TDOC Z TA245.7 B873 NO.1307 . “Two Bwl 307 y’ Of Alternatives For Improving Honey Mesquite-- Infested Rangeland ,',> ' } ‘ \_\\\‘;~‘\\\ \. ‘l ‘ \ . x g _\\_\\ ~~Q \i The Texas Agricultural Experiment Station, Neville P. Clarke, Director, The Texas A&M University System, College Station, Texas Economic Comparisons [Blank Page in Original Bulletin] B-1307 ECONOMIC COMPARISONS OF ALTERNATIVES FOR IMPROVING HONEY MESQUITE-INFESTED RANGELAND R. E. Whitson and C. J. Scifres WM‘ Associate Professor and Professor, Texas Agricultural Experiment Station (Departments of Agricultural Economics and Range Science} The Texas AGM University System. [Blank Page in Original Bulletin] SUMMARY. INTRGJUCPION . DEVELOPMENT OF PRODUCTION RESPONSE CURVES. BRUSH MANAGEMEIVI‘ ALTERNATIVES EVALUATED. Aerial sprays . _ Individual-Plant Chemical Treatments. Oiling. Tree Dozing (Power Grubbing). Low=Energy Grubbing . . Chaining. Root Plowing. Roller Chopping . Shredding . Raking/Stacking . ECONOMIC ANALYSIS. Cost/Revenue Characterization . Factors Influencing Selection of Alternatives . RESUETS. . . High Plains . Rolling Plains and Rolling Red Plains . Grand Prairie and Cross Timbers. North Central Prairies. Blachland Prairies. Texas Claypan Area East Texas Timberland . Rio Grande Plain Coast Prairie . 21 21 24 24 24 25 25 26 26 26 27 27 27 35 36 36 47 68 81 106 113 118 127 Edwards Plateau. Central Basin. Trans-Pecos. . . DISCUSSION. A . REFERENCES CITED. . APPENDIX. O I 0 0 0 Q O I 0 I I O 0 Q I I "H - 132 - 150 - 157 167 175 - 176 - 180 sUmmRY Economic responses to honey mesquite control were estimated for each of the major land resource regions in Texas. The results pertain to individual ranch firms, and cannot be extrapolated to the total industry without ascertaining the impact of potential suply/demand shifts on cattle prices. The economic analysis utilized a net present value and capital budgeting techniques for a 20-year planning period to estimate annual rate of return (internal rate of return), net present value for a 9 percent discount rate, and net cash flow for alternative mesquite control practices. Net cash flows were expressed in constant l978 dollars and were developed for alternative weaned beef price scenarios of 34 cents to 54 cents per pound over the 20-year planning horizon. Economic results varied considerably among and within vegetation regions. The variation was a function of range site potential, degree of honey mesquite infestation at the time of treatment, and the control alternative selected. Aerial application of 2,4,5—T consistently produced the highest annual rates of return, regardless of vegetation region. Based on the highest rates of return from each vegetation region, the unweighted average anal rate of return was 15.9 percent. When 2,4,5-T was eliminated as potential control measure, dicaba produced the highest annual rate of return (ll.4 percent), approximately one—third less than that from 2,4,5-T. The simple average of the highest average annual rate of return from each resource region for non-herbicide treatments was 5.7 percent, The average cost of mechanical methods, based on l978 dollars, would have to be reduced by approximately 50 percent to generate a 9 percent annual rate of return. Assuming long term rainfall patterns and average cattle prices, the average length of time required to recover all investment capital for treatment and additional livestock with 2,4,5-T (8.5 years) was about Averaged (unweighted) across all resource regions, the net annual cash flows half that for the "next-best" herbicide treatment (16 years). increased 2.25 dollars per acre from the "next best" non-herbicide alternative. However, it was not possible to identify any single "best" honey mesquite control practice since producer preference is a critical criterion for treatment selection. While aerial application of 2,4,5-T produced the highest annual rates of return, a producer could logically select another practice if it met his minimum rate of return criterion, capital was not limiting, and the practice produced higher annual net cash flows than 2,4,5-T. Selection of a practice other than aerial application of 2,4,5-T necessitates greater investment capital requirements. Ranchers typically have pay—back periods which are shorter than pay out periods for brush control. Consequently, as investment capital requirements increase, pay out periods increase, thereby increasing cash flow deficits. Such situations require a transfer of cash from other sources to meet these deficits. Small producers (93 percent of all Texas ranch producers have 200 or fewer cows) have fewer cash sources (because of cash consumption requirements within the ranch firm) to offset an increasing cash flow deficit than do larger producers. No industry supply shifts were evaluated in this study. However, it can be anticipated that if brush management becomes more expensive, fewer acres will be treated. Over time, this could result in a reduction in 1 v-I the supply of beef which will cause prices to increase. The net result on beef prices will depend on the nature of the supply shift relative to demand characteristics for beef. EIIIWJMIC CIBEHURISONS OF AIHEHUQNTIVES Fffii IMPROVING-HONEY MESQUITE—INFESTED RANGELAND R.E. Whitson and C.J. Scifres INTRQDUCTION According to a recent ccnmfilation, there are nearly 86 million acres of rangelandl/ in Texas (Table l). These native grazing lands form the backbone of the State's range livestock industry and provide food and cover for most of its wildlife. However, during the past century, the density and stature of woody plants has increased dramatically. The present brush cover prevents achieving potential forage production from most native grazing lands in Texas. The most cosmopolitan woody plant problem, honey mesquite (Prosopis glandulosa Torr. var. glandulosa), infests almost 55 million acres in Texas. Consequently, considerable research effort has been focused upon development of methods for allevia- ting the detrimental effects of the mesquite problem. Most success has been achieved in the development of mechanical and chemical methods of mesquite control. A variety of techniques have been successfully applied during the past 25 years. However, during the past 5 to l0 years, interest in the econcnuc performance of the techniques has intensified because: (1) The rising costs of equipment and energy have seriously influenced treatment costs at the producer level, especially with mechanical honeyl mesquite control; and, 1/ Selected terms are defined in the appendix and may be helpful in proper interpretation of research results reported herein. .m=N@N@ wwm N=NNN¢¢ m@@=NQ=H = .A<@@Nv =N;H=@=u@¢ vcm :~@Ew Eonw mopmsfiwmo moam co woman m .mowoum x-m~uwm@uaw @=@N >:m ow:~u:N Ho: wwow .>uc:ou xn -wm~v xHo~=o>c~ muwuz =oHum>~@m:ou wmxoe co comma m o>Nwummmoa o :N Q :.mmm>m%u mwxwe ms» mm susm mmonm new mo:Hw> mommonucfi suflzz moan muasommn wcmfi pohme . aw . w Q N N u w =m@=@NE¢~@om= pmsu wmooxm muopmwcsv omzuz wcm nmpamu .>m~mwou EOHW wo~mmw< o .m@NQ@@m nmswo cw“: onswxfis 2“ no mucaum wnsm cfi mwcmfim moamuumum mm wofiv no>ou xmocmu w .woN|o~ no>oo >@¢=~u Q NONA ao>ou >@¢=@u n .om:ommoa oafimccoficfimo co woman m mm N NM Q m~ N>< NNN.@Nu w¢x@@ Nm Nv NN fiv mfi Nmm mow ¢¢m.NN w@n@mam @=¢NxQNNm v NN mm oN ofl wwN ¢@@.N ¢¢¢.N m@N~N@N@ wcmnw vm m . wfl N NN ow ov~.~ ooo.m mhonsfih mmonu ¢_ MN mN N mq o~o.~ oom.m oom.o m@NNN¢NN N@-=@u =-oz .m¢ o~ ¢N Q NN ¢@w.NN w¢@.mN ¢¢¢.N~@z Duswwq Jowmnowoz bmmcoc woumowcfi 1 oefim mam ao>ou N@¢=@uJ wcm~om:mm M xn hwy cowumwmomcfi ouwsvmmz fiwonum mo mccmmsospv moam new; .mflXOP W0 mmonm QUHUOWQH wcmfi Momma esp cfizpwz Hmwucowom ouwm can ao>ou xaocmu >2 cofiumwwomcfi mpfisvmos osw mo cowwsnwnwmwa .~ m~nmP é. (2) Increased scrutiny by society of chemical use in agricultural production systems has prompted federal agencies to challenge the use of certain herbicides for range improvement . Although these pressures are not restricted to range livestock production, rangeland as a contributor to national agricultural productivity “has some unique characteristics which provided the impetus for this study. 'Ihe importance of rangeland to agricultural production on both the State and National levels is related to the massiveness of the resource rather than / to potential high axmual productivity on a per acre basis. Rangeland is h managed extensively as contrasted to the highly intensive management efforts required for row crop agriculture. Consequently, rangeland, relative to most short-term economic criteria, is viewed by industries such as herbicide manufacturers as a "minor crop" (Scifres and Merkle 1975). Therefore, relatively few of the herbicides registered for agricultural production are cleared for use on rangeland, For these reasons, refinement of equip- ment for row crop agriculture has surpassed mechanization advances for range livestock production. Removing or constraining use of any given production alternative for range improvement may result in relatively few remaining alternatives, Moreover, there is little economic information on which to base sound decisions; either at producer or federal levels regarding the economic impact of retmving or constraining selected alternatives. With herbicides for example, the major research thrust has involved investigating efficacy, toxicology, application technology, and environmental implications rather than the economics of their use for brush management. Unfortunately, trial and error economic evaluations have formed t the primary basis for acceptance of various brush management practices at the producer level. Apparently, this has been deemed an acceptable procedure on the rationale that variation among enterprises and management objectives strongly influence economic acceptability—-a practice may be judged to be economica-llY feasible by one producer and fail to perform satisfactorily in another management situation. There is no argument that variation in individual management effectiveness strongly influences performance of any range improvement practice. Yet, sound benefit / cost analyses are essential to the decision-making processes concerning adoption of any agricultural practice, regardless of the characteristics of a specific situation. This study was conducted under the assumption that effective management was utilized for carrying out mesquite control practices. DEVELOPMEDTT‘ OF PRQDUCTION RESPONSE ctmvms The lack of estimates of annual production responses to treatment has been the major restriction to economic analysis of bzrush management alter- natives . Very little research on brush control has been conducted with long-term product ion response as a primary criteron for treatment evaluation. Such research is lirmited because: ' (1) Investigators have traditionally placed most emphasis on treatment performance relative to response of target species with little regard for the forage component. (2) Experimental plots are usually not of adequate size to allow evaluation of forage / animal performance across all major range sites or researcher control has yielded to management requirements of cooperators who furnish the land causing response data to be confounded with pattern of land use and periodic changes in production practices. ( 3) Long-term response data are generated from investigations which span mdmany years and require continuity of evaluation which has not been possible because of cost , personnel changes and short-term research goals. Even in the few cases where these constraints have been circumvented, experimental approaches have invariably ‘provided data of limited applicability because the research has been necessarily confined to a rather narrow region and/or does not adequately duplicate actual production conditions. One approach to overcoming the time and cost limitations to collecting actual production data is to utilize estimates of persons experienced with brush nanagement practices. The research herein is based on "best estimates" by range trained personnel with experience in the particular resource area for which they were queried. This approach allowed assimilation of working experiences of selected respondents into usable estinates for relatively large land areas. The respondents were asked to provide critical information which affects production responses to brush management alternatives including: (1) Major land resource area (by precipitation/evaporation zone). The absolute responses of range vegetation to any management effort is governed by the potential of the vegetation resource, especially in relation to effective moisture, soils and growing season. Response data provided by counties were further grouped into homogeneous sets by the respondents. Sets were based on relative potential productivity with- in each major land resource area (Figure l) in the state. (2) Land use of resource surveyed. The respondents provided estimates of acreages of rangeland, cropland, tame pasture, woodlands and all "other" land uses. These data allow projection of the potential impact of constraints on brush management alternatives on a regional basis. (3) Kinds of livestock. The typical ratio (based on animal units) of kind of animal (cattle, sheep, goats, horses), principal types of operations (breeding [cowecalf etc.] stocker [steers, lambs] or mixed), and acreages of typical operations were provided by counties. For these analyses, the response curves were based on cow/calf produgtign Qnly, This was done because of the statewide adaptability High Plains Rolling Plains Rolling Red Plains North Central Prairies Cross Timbers Grand Prairie Blackland Prairies FSPWPPP?‘ 10. 11. 12. 13. 14. Texas Claypan Area East Texas Timberlands Coast Prairie Rio Grande Plain Central Basin Edwards Plateau Trans-Pecos i-‘lajor land resource areas of Texas. 10 of the cow and to reduce the number of alternatives in the analysis. (4) Range siteppotential. Since range sites are unique vegetation/ soil complexes within climates, the production responses to any given treatment may vary widely among sites. However, to identify responses for every range site in Texas would be virtually impossible because of the large number of sites per major land resource areas. Nbreover, such an approach would be impractical since managenent units are typically composed of a complex of sites rather than any one range site. Therefore, the respondents were asked to consider two broad site categories, g§gp_and shallow, for formulating their response estimates. In this report,_g§gp_§it§§_are those of moderate to high production potential-—those range sites with well-developed, deep soil profiles of high moisture—holding capacity. Shallow_§ite§ are those of relatively low production potential-—those sites typified by soils of low production potential and which are usually droughty by nature. These terns arerelative, and must be used 9_n_ a gparative basis and_in the context_gf_major land resource area. For instance, a "deep" site in regions of high rainfall may have considerably higher production potential than a "deep" site in arid regions. (5) Degree of mesquite infestation. The density of brush cover on any given site greatly influences the relative response to brush management alternatives. Greatest relative production responses generally occur following treatment of deep sites supporting heavy brush covers. Conversely, the least relative response would be expected from treatment of range sites which support little brush cover. In fact, range sites with low brush cover are generally 11 considered maintenance problems, or they are not considered for treatment until the brush cover becomes luniting to range forage production and/or livestock handling and care. Approximately 39 percent of the State's mesquite infestation is a light canopy cover (Table l). Consequently, two broad categories of mesquite infestation, nedium (canopy cover 10 to 20 percent) and high (canopy cover greater than 20 percent), were evaluated in this study. (6) Treatment/treatment sequence. The respondents listed the brush zmmmunmmnnzalternatives in the order of use as based on acreages treated in their area of responsibility. Since a 20—year planning horizon was selected for study, they were also asked to indicate the followup treatment normally applied and the frequency'of application for maintenance of range unprovement from the primary practices. (7) Treatment life. The life of any treatment, the time from appli- cation until retreatment or application of another practice is deemed necessary, varies with vegetation region, range site potential, and initial brush cover. It was assumed that the initial investment in mesquite control would not lapse but that the appropriate followup treatment would be applied before the brush cover reached original proportions. (8) Frequency of followup treatment. The normal frequency (years after application of initial treatment) of followup treatment was indicated by the respondents to facilitate estinmtes of timing and magnitude of cost inputs over the 20—year planning horizon. (9) Current treatment costs. The respondents submitted 1978 costs (dollars per acre) of each initial and maintenance treatment. These data were verified by contacting individuals in the chemical industry, 12 heavy equipment contractors, aerial applicators,and ranchers in most of the major land resource areas. (10) Livestock production responses to treatment. _0f the information required for range economic studies, livestock production response data have traditionally been the most difficult to obtain. The respondents estimated the average carrying capacities (acres per animal unit) before treatment (year zero) and after treatment, thexmndnmmxcarrying capacity after treatment, and the time (years) required after treatment to achieve the maximum carrying capacity. All estimates were forrmllated k for average rainfall conditions. Although it is understood that drought can nullify treatment effects following application of brush.nanagement alternatives and that higher than average rainfall may accentuate the responses to honey mesquite control (Scifres and Polk 1974; Scifres, Durham.and Mutz 1977), consideration of the economic hnpact of that variation was beyond the scope of this study. The general response curve of Workman, Tefertiller and Leinweber (l965) (Figure 2) for aerial spraying of honey mesquite was adopted for this study. This response curve was modified slightly in that carrying capacity (acres per aninal unit) changes were used as adjusted for proper grazing use on a yearlong basis (Figure 3). In addition, a 20-year planning horizon was used so that followup treatments could be incorporated. The 20-year planning horizon was felt to be adequate for relative comparison of livestock responses among treatments assuming average annual rainfall conditions. There were several a assumptions and/or response alterations in adapting the response curve to the major brush management/range site/brush cover situations including: .700 - .650 ' .600- .550 Grazing rurflAUIWs/Acro) .500 - l I 1 l l J_ A I l 1 -I 0 I 2 3 4 5 6 7 8 9 l0 ll l2 Years before and after grazing Figure 2. Response curve of Workman, Tefertiller and Leinweber (1965) used for estimating rates of grazing by years before and after aerially spraying honey rnes- quite on upland range sites on the Rolling Plains of Texas. , 13 response Rotroatmom .700’ 7 23 Q .650- ‘D I a j .600“ . Untreated E “.550 E ‘i 2 0.500’ O I A A A A A A n l I A A I A A A A A A L A; -IOIZ34567B9l0lll2l3l4l5l6l7lBl92O Your: aflor tnutmcm Figure 3. Modification of the response curve of workman, Tefertiller and Leinweber (1965) to include retreatment of honey mesquite-infested rangeland over a 20-year planning horizon. 15 (a) Retreatment was scheduled when the brush canopy cover had been replaced to the extent that the maximum carrying capacity was reduced to the estimated 20-year average carrying capacity for the treatment. (b) The length of time between retreatments was increased in longevity (for example, the increase was l year in the case of aerially spraying with 2,4,5-T) to account for range improve- nent accured from the initial treatment. Whereas the resident forage species may be of relatively low grazing value prior to the initial treatment of brushland, higher-value species establish following treatnent under proper grazing management and are present at the tine of retreatment.. Thus, retreatments were generally applied to sites in better range condition than were the original treatments. (c) All response data were developed as if grazing management effectiveness was adequate to avoid range deterioration following treatment. As with variation in rainfall, it was beyond the scope of this study to evaluate the flnpact of management effect- iveness as a variable,tnn:nanagement was assumed to be adequate. (d) The relative magnitude of response varied with initial brush cover on the range site (the relative response to treatment was greater on high than on mediunxinfestations on a site of a given production potential), and with site potential (response was greater on deep than on shallow soils) for all alternatives, based on estimates of the respondents. (e) The1mvdnmm1response varied with effectiveness of herbicides on associated species. For instance, a mixture of 2,4,5-T + picloram (4-amino-3,5,6-trichloropicolinic acid) more effectively controls broadleaved weeds such as annual broomweed (Xanthocephalum dracunculoides) than does 2,4,5—T alone (Scifres, Brock and Hahn 1971). It also controls species such as pricklypear (Qpuntia sp.) and other perennials normally associated with honey mesquite. However, aside from consideration of such species which are usually associated with honey mesquite, it assumed that no other major species occurred in the stands. For example, this analysis did not consider honey mesquite as occurring with signficant aneunts of other woody species on the South Texas Plains but as essentially pure stands. This assumption caused vegetation response differ- ences on the South Texas Plains between 2,4,5—T and the 2,4,5-T/ picloran1ndxtures to be estinated.sonewhat more conservatively than would usually occur (Scifres, Durhanmand Mtz 1977). (f) Where mechanical treatments were followed by artificial reseeding, grazing was assumed to be deferred for l year after treatment and to be reduced by 50 percent the second year after treatment to allow forage stand establishment. (g) Followup treatments were applied to ensure a treatment life of at least 20 years. Where treatment life exceeded 20 years, a salvage value was determined for the treatment/retreatment based on the remaining effective treatment live as a percent of total projected treatment life. (ll) Labor savings. The respondents also provided estimates of annual savings (dollars per acre) in labor for handling and caring for the livestock following application of the brush management alternatives. Efficiency of handling and care of livestock is often the basis of scheduling retreatment of brush, even before the available forage 17 supply is reduced by increasing canopy cover. (12) Wildlife implications. These analyses were conducted on the assumption that all brush management programs would consider the need for quality wildlife habitat, and that treatments would generally be applied in such a manner as to deteriorate the habitat. This assumption was essential to the analyses because of the extreme diversity in vegetation, wildlife management goals, and even differ- ences in gane»species on various enterprises across the state. Since wildlife management is now approached on an enterprise by enter- prise basis, introducing wildlife habitat as a variable would result in an infinite array of analysis possibilities. Moreover, there is little data relating the economic response of wildlife to honey mesquite control. However, some broad generalizations concerning the use of some brush management methods on wildlife habitat are possible. Complete treatment of a.management unit with herbicides, especi- ally those containing picloram, is less desirable for wildlife habitat maintenance than spraying strips alternating with untreated strips of brush. Aerial spraying 80 percent of a mature honey mesquite brushland in alternating strips with 2,4,5-T + picloranlat l pound per acre total herbicide did not adversely affect populations of white-tailed deer (Odocoileus virginiana), nilgai antelope (Boselaphus tragocamelus), wild turkeys (Meleagris gallopavo) or feral hogs (Sus scrofa) in South Texas (Beasom and Scifres 1977). Complete spraying of range- land caused at least short-term population shifts with all species except nilgai antelope. The detrimental influence of complete spraying on white—tailed deer habitat was attributed to a reduction in production and species diversity of forb populations (Beasom and Scifres 1977). Total treat- ment apparently reduced habitat quality for wild turkeys by seriously reducing canopy cover of roosting sites and by reducing masti a desired food item. Feral hogs reacted negatively to complete spraying apparently because of reduced availability of mast, especially acorns and mesquite beans. The only species that reacted negatively to both strip— and complete spraying in the study of Beasom and Scifres (1977) was javelina (Eecari_taQa§u). This response was attributed to the preference of javelina for pricklypear as a food item, which was reduced significantly by both treatments. Tanner, Inglis and Blankenship (1978) conducted an experiment similar to that of Beasom and Scifres (1977) in the western portion of the Rio Grande Plains. They found that white-tailed deer tended to evacuate a 4,500-acre pasture for 5 months following strip spraying (80 percent sprayed) with 2,4,5-T + picloram at 0.5 to l pound per acre. However, deer were attracted to the treated pasture in above normal numbers the following winter and returned to normal numbers ll months after spraying. They attributed these shifts to availability of browse which was initially reduced by the herbi- cide. Surviving plants developed succulent regrowth the year of herbicide application and the regrowth matured the year after treat- ment. Darr and Klebenow (1975) felt that the effect of spraying on browse was beneficial to deer in the Rolling Plains of North Texas. Whitson, Beasom and Scifres (1977) reported that strip—spraying of brush tended to maximize economic returns to land owners, and l9 apparently, it offered a hedge against low cattle prices when compared to complete treatment or no herbicide use. For example, complete spraying was economically feasible based on a 10 percent discount rate and a 9-year projected treatment life when cattle prices averaged at least 49.5 cents per pound. However, when cattle prices were lower, partial treatment was preferable economically because returns from lease hunting, where 20 percent of the brush was left untreated for wildlife habitat, more than compensated for returns frm cattle production. Deer use following brush control is influenced by the inter- action of habitat and treatment characteristics (Darr and Klebenow 1975). For instance, chaining bottomland habitat in the Rolling Plains reduced deer use, and the larger the area chained, the less it was used by deer. Therefore, as with herbicides, mechanical methods should not be applied to entire managment units if Wild? life habitat is a consideration. Application of mechanical methods in strips, preferably following major breaks in topography and with occasional disruptions to increase edge effect, will prevent significant reductions in wildlife habitat quality (Scifres 1979a). Bkneover, sensible application of these methods can be used to effectively improve wildlife habitat. Species of wildlife desired is also an important consideration. Whereas clearing the woody plants and stimulating grass cover may not be ideal for white—tailed deer, quail (§Qlinus'virginiana) and other upland game birds prefer grasslands with scattered brushes for nesting cover to heavy brush stands. (12) Indirect effects. There are a number of effects attributed to brush management in addition to the direct econmic responses. Many of these effects are conservation responses that have not been documented on a research basis, and which have not (or presently cannot) be assigned a monetary value. These include soil conservation, increased water yield, and decreased sedimentation. Also, this study did not entertain the indirect effects of the treated management unit on associated units. Treatment of one pasture of a ranch can result in improvement of other pastures through increasing the deferment time for untreated pastures. This research considered the treated management unit as an isolated entity. It is conceivable that a producer might accept a zero rate of return fron a brush management treatment if the investment offered adequate conservation opportunities. ‘However, until a dollar value can be assigned these indirect effects, they can be utilized only to embellish economic interpretations. Conversely, in some areas, brush control is considered a detri- ment to land values for certain segments of the real estate market. Land values for certain nonagricultural uses, especially "ranchettes“ and retreats for the urbanite, may be reduced by removal of woody plants. Potential cost decreases as indirect results of brush nanagement include reduced veterinary costs because of increased ability to care for sick and diseased animals, and potential reduction in number of breeding males required. Again these benefits vary widely and the relative magnitude is influenced by managerial effectiveness as it interacts with brush management at the firm level. 21 BRUSH MANAGEMENI‘ ALTERNATIVES EVALUATED Since the brush management alternatives include an evaluation of chemical and mechanical methods, a brief discussion of their use and characteristics is important to understanding results of the economic comparison. Because of the lack of widespread application, biological methods, such as goating, and prescribed burning, are my; discussed_ This does not mean that their use in certain situations is not important for honey "Bsqllite COIItrOl, “and that their use will not become more widespread in the future. Prescribed buming- technology is still in the formative stages, and goating is limited to areas of the animal's adaptation. Aerial §prays Honey Inesquite is most susceptible to foliar-applied herbicides at 40 to 90 days after bud burst. Depending on vegetation region, the Texas "spray season" usually lasts from the first week in May to the first week in July. The herbicides are applied primarily with fixed-wing aircraft usually in spray swaths 36 to 42 feet wide. The usual herbicide carrier is a diesel oilzwater emulsion, l gallon of diesel oil and enough water to total 3, 4, or 5 gallons per acre of spray solution. These carriers are referred to as "standard volumes." In some areas of the kState, especially the Rolling Plains and Trans-Pecos, it has become increasingly popular to apply the herbicides in only l gallon per acre of the diesel oilmrater (1:3) emulsion. This practice is referred to as "low volume" spraying. The cost components of aerial spraying include herbicide, diesel oil, emulsifier, and application (hauling of materials, mixing of spray, and application of the spray including loading, flying and 22 flagging). Cost of several of these components are reduced, compared to stan- dard volumes (Fishefet a1 . 1974') where low-volume applications are mssible. Only a brief discussion of herbicide alternatives for aerial spraying will be discussed since detailed comparisons of the herbicides are available (Scifres 1973, 1979a) (1) 2,4,5-T. The standard brush herbicide since the mid 1950's, 2,4,5—T, is the most popular treatment for honey mesquite control in Texas. It is generally applied at 0. 5 pound per acre in the northern g and western parts of the State but may be applied at 0.67 pound per acre in the eastern third (average armual rainfall greater than 28 inches) of the State. Many species of broadleaved weeds are controlled by 2,4,5-T although it is generally not as effective against herbaceous species as are more recently developed herbicides. The herbicide 2,4,5-T is sold LITIdBI‘ many tradenames and is available in various forrmilations. (2) '2,4,5-T + picloram. Picloram was formally introduced in the 1960's (Haneker et al. 1963) and has been used for brush control in Texas since the early 1970's as a 1:1 commercial mlixuzre with 2,4,5-T. The 2,'4,5-T+pic1oram combination is synergistic for honey mesquite control (Bovey, Davis and Morton 1968), and kills, on the average, about '42 percent compared to a longterm average of 26 percent mortality 0f honey" mesquite treated with 2,4,'5-T only (Fisher et al. 1972). Addition of picloram also increases the spectrum of associated species controlled, both herbaceous and woody (Bovey and t Scifres 1971). The 2,4,5—T + picloram mixture is generally applied at 0. 5 pound per acre for honey mesquite control but 1 pound per acre may be used where a proportion of hard-to-kill woody species are associated in the stand such as on the Rio Grande Plain, Coastal 23 Prairie or Edwards Plateau. (3) 2,4,5-T-+ dicamba (3,6-dichloro-0-anisic acid). Dicamba and 2,4,5-T are commercially available in.a l:l mixture. In contrast to the mixtue containing picloram, the 2,4,5-T + dicamba mixture is additive for honey mesquite control (Scifres and Hoffman 1972). The combination broadens the spectrum of herbaceous species con- trolled somewhat, compared to 2,4,5-T alone, but usually does not increase the number of woody plant species controlled. The same rates of the 2,4,5-T+dicambacotnbination are used as when 2,4,5-T is applied alone. (4) Dicamba. Honey mesquite control with dicamba is usually equi- valent to that resulting from.the same rate of 2,4,5—T alone applied under the same conditions (Scifres and Hoffman 1972) in the eastern two-thirds of Texas. However, the effectiveness of dicamba apparently increases in the drier portions of the state, generally the Trans- Pecos vegetation resource, and in.New Mexico. Conversely, the herbi- cide apparently performs in.a less predictable manner in.the wetter (eastern and southeastern) portions of Texas. Dicamba is not usually used alone for honey mesquite control but was included in this study because of its performance similarities to 2,4,5-T and 2,4,5-T + dicamba. Moreover, should use of 2,4,5-T be eliminated for brush control, dicamba is considered the "next best" alterna- tive from the standpoint of registered herbicides for honey mesquite control.§.For purposes of this study, forage and livestock responses were assumed to be the same for 2,4,5-T and dicamba. 24 Individual- Plant Chemical Treatments Individual plant treatments may be applied as foliar, cut-stump, or basal sprays but the latter is usually preferred for range situations. Single—stemmed plants or those with few stems haying diameters of 5 inches or less on rocky, porous or sandy soils are most easily controlled with basal sprays. Herbicide is usually nixed at 4 to 8 pouds (active ingredient) in 100 gallons of diesel oil or kerosene. The lower 6 to 8 inches of the trunks should be wetted to runoff. Basal sprays nay be applied at ahmost any time of the year but sunuer treatments are generally used. One to 2 pounds of herbicide in l0O gallons water or diesel oil water emulsion are used for individual plant, foliar sprays. The foliage should be wet thoroughly but not to runoff. Treatments are generally most effective in late spring as are broadcast sprays. 9212s Oiling is one of the oldest methods of honey mesquite control. One pint to 2 quarts of diesel oil or kerosene is poued around the base of each tree to wet the bark and soil to the lower most dormant bud. Best penetration of the oil occus when the soil is dry and pulled away from the base of the trunks. Tree Dozing (Power Grubbing) Power grubbing is most effective for stands of widely-spaced, single- stenned honey mesquite plants on sites supporting good forage cover (Scifres 1973). The woody plants are uprooted below the lower most bud 25 leaving a "pit" in the soil. The pits trap moisture and may be individually seeded to enhance the grass stand. Power grubbing is also used as a "clearzup" or maintenance treasure following other methods. Standard power grubbing operations usually employ crawler tractors of 100 horsepower or larger that are equipped with a front-mounted, U-shaped "stinger" blade. Efficiency of power grubbing varies widely depending upon size of the plants, stand density, and soil texture and water content. low-Energy Grubbing "Low-energy" grubbirxg refers to the use of a 65-horsepower or smaller crawler tractor with a modified hydraulic system and automatic transmission. Low-energy grubbing is more cost efficient than standard power grubbing for controlling sparse to moderate. stands of honey mesquite on rangeland (Wiedemann, Cross and Fisher 1977). ‘Therefore, it is an excellent maintenance practice and was included as such in this study. low-energy grubbing also appears promrising for controlling other woody species such as huisache (Bontrager, Scifres and Drawe‘ 1979). hainin Chaining refers to dragging a heavy—duty anchor chain (80 to 100 pounds per foot), usually 200 to 300 feet long, between two crawler tractors to uproot brush plants.. (lmzhiing is most effective when the plants are large enough to be uprooted rather than bent under the chain and when soil—water content is adequate to allow uprooting. It can be used on relatively thick stands. "Double chaining," covering the land twice with the second trip in the opposite direction to the first, is more effective than one—way chaining (Scifres 1973). Chaining also is used effectively following aerial spraying of honey mesquite 26 Root Plowing The root plow is a large (l0 to l6 foot) straight or V>shaped blade mounted on a heavy duty crawler tractor. The blade is usuallyipulled l0 to 16 inches below the soil surface to sever the roots and dislodge the honey mesquite plants, Its best use is clearing dense brush stands on deteriorated range sites of high production potential in preparation for artificial seeding. When root plowing is used without artificial seeding, the rate of vegetation replacment, because of the soil disturbance, is relatively slow Gfiutz et ta al. 1978). Roller Chopping Roller choppers are constructed by attaching heavy duty blades to run lengthwise on drums and vary widely-in size and weight. The drums 3 are usually filled with water to increase their weight, and pulled over the brush to crush, mash and cut off the woody plants. Roller chopping causes nfirunel soil disturbance and is a means of rapidly reducing the brush cover. However, since damage is inflicted only upon the woody plant tops, under- ground buds and those along surviving stem segments rapidly develop regrowth. 1 Tflue effect of roller chopping on the brush plants is essentially the same as E shredding. However, larger plants are cut off by roller choppers than with conventionalshredders, and roller choppers are better adapted to the rough terrain of rangeland. Also, the cuts made by the roller chopper blades into the soil surface may trap and hold water that would normally run off undis— ‘U turbed rangeland_ When the soil is danm>or wet,the roller chopper can tear up herbaceous vegetation as well as the soil surface. Shredding l Large, flail-type shredders may be used to temporarily reduce the brush 27 cover on rangeland. In general, conventiaonal shredders are effective only on those woody plants with trunk diameters of 2 inches or smaller. Therefore, they are used primarily for maintenance following use of other methods. Although relatively large shredders of improved durability have been developed recently, they have not been in use long enough to allow economic evaluation. Raking[Stacking Large rakes attached to the front end of crawler tractors are use to push the woody plants into stacks. The stacks are usually burned to remove the debris or if seedbeds are to be prepared for artificial seeding. Drag-type rakes (root rakes) often are used to dislodge brush roots fnan the soil and place them in windrows. EIIEKPHC ANALYSIS Cost/Revenue Characterization A capital budgeting net-present value analysis was utilized to evaluate the brush.nemegement alternatives. Use of this method required identifi- cation of the following economic data: (1) Cost increases. Increased costs associated with brush management included expenditures for the brush control practice(s), added breeding livestock, and added operating expenses. These costs were expressed in 1978 dollars for a projected 20-year planning horizon. Texas Agricultual Extension Service budgets were used to identify operating costs in each resouce region.of the State. These budgets were adjusted to include costs that were expected to increase as the result of increases in the livestock breeding herd following brush 28 management. Fertilizer costs (Ilolt et :11. 1976) were included for tame pasture alternatives. Estineted annual costs ("out—of-pocket" only—- not fixed costs) are smmarized by Vegetation Region in Table 2. Total costs (including application) of 0.5 pound per acre (active ingredient) for conrrercial formulations of 2,4,5—T, 2,4,5-T + dicamba, dicamba, ad 2,4,5-T-+-picloram were estimated to be 5.50, 5.95, 7.50 and 9.75 dollars per acre, respectively. For 0.67 pound per acre, the costs were estimated to be 6.16, 6.75, and 8.85 dollars per acre for 2,4,5—T, 2,4,5-T + dicamba, and dicamba, respectively. The 2,4,5—T + picloram combination was assured to be applied only at the 0.5 pound per acre rate. Silvex was also included in the analysis; however, because of its limited potential use, economic results were not presented in the tables. Silvex could not logically be considered a substitute for 2,4,5-T since it also is being evaluated relative to potential with- _ drawal or regulated constraints on its use. Thus, it was assumed that constraints on use of 2,4,5—T would also apply to silvex. Costs of mechanical alternatives varied with major land resource area and are presented in the discussion of results. Costs for any treatments requiring a deferment period included a land rental fee for the year (s) of deferment. This armual cost was assured to average 60.00 dollars per cow. (2) Revenue increases. Estimated increases in revenue were identi- fied for cow-calf operations for each brush management alternative in each vegetation region. Somrces of revenue increases were (a) increases in the size of the livestock herd, (b) increases in weaningweights of calves from original cows grazing the land before treatment, and (c) increases in percentage weaned calf crop from the original i k 29 Table 2. Estimated pretreatment livestock production and variable cash costs per cow used for economic comparison of honey mesquite control alternatives, Texas. Before treatmenta variab1e cashb 'Weaning Weanedl . costs ($/cow); Major land weights calf-crop Tame resource area (lb/Calf) (%) Rangeland pastures High Plains 424 89.0 78.76 - Rolling Plains 439 88.0 72.02 112-02 Rolling Rea Plains 439 88.0 72.02 112.02 Cross Timbers 410 84.5 79.42 109.70 North Central Prairie 466 87.5 79.42 130.19 Grand Prairie 414 86.5‘ 82.47 113.23 Blackland Prairie 400 80.0 79.70 119.70 Texas Claypan 389 78.8 79.70 101.36 East Texas 388 80.0 79.70 101.36 Coastal Prairie 395 76.0 69.78 94.26 Rio Grande Plains 440 77.6 63.24 107.47 Edwards Plateau 408 85.0 68.92 108.92 Central Basin 408 85.0 68.92 - Trans-Pecos 434 81.0 65.53 - State Average 418 83.3 74.26 110.02 a . . . . . . Livestock production estimates by Soil Conservation Service personnel. Weaning weights represent an average for steers and heifers. Variable cash costs from Texas Agricultural Extension Service Livestock Budgets, 1973-1979- These costs represent an estimated increase in annual expenditures (less interest on investment) if one additional cow was added to an existing breeding herd. 3O cows grazing the land before treatment. Selling price projections to the year 2000 were obtained frcnlthe U.S. Department of Agriculture (Smith, Dec. 1978, personal communication) and were expressed in 1978 dollars. For this study, six alternative weaned calf prices, ranging fron134 to 54 dollars per hundredweight were used to estimate economic; feasibility of mesquite control. A selling price of 44 dollars per hundredweight was projected as an average price (1978 dollars) for weaned steers and heifers over a 20-year planning hortamiin order to \ present relative economic comparisons. No livestock price cycles were incorporated in the study because of the longeterm nature of the planning horizon. However, adjustment factors for annual rates of return and cash flows were developed for each mesquite control alternative for livestock prices ranging from 34 to 54 dollars per hundredweight. The results of the study would have been more conservative if the initial portion of the 20-year planning horizon represented the ufavorable portion of the livestock cycle. Conversely, if the initial years represented the portion of the cycle with favorable prices, results would be more favorable toward.implementing brush nenagement practices. No industry suply curve shifts were assumed to occur as a result of brush.management. If shifts occu because of widespread adoption or elindnation of brush control alternatives,the results of these analyses would need to be adjusted accordingly. A.decrease in supply \ could likely have a positive impact on total industry revenue because of the inelastic demand for beef at the ranch level. However, if any sclectcd mesquite control practice were discontinued, reduction in supply would not likely occur uniformly among ranch firms. Thus, 31 the portions of the industry with mesquite infestations would be affected by a ban on a given control and could bear a disporportionate amount of the economic loss because of the non-uniform losses of production capability. Increases in revenues frcm indirect production responses were not included in the study. As mentioned previously, a ranch manager could expect to increase carrying capacity indirectly from non- treated areas if, by treating a portion of his ranch, a deferment period was provided for the non-treated areas. Conversely, the manager could expect, in many cases, continued decline in carrying capacity over time if no brush management was undertaken. For this study, the "before treat- mient" carrying capacity was utilized as a constant value over the 20- year planning horizon. Projected carrying capacities "after treat- ment" were always ccxnpared to the carrying capacity which existed at the time of treatment. (3) Cost decreases. It was assumed that reduced labor require- ments was the only cost decrease associated with brush management, and was related only to the original cows utilizing the treated areas. Net cash flows were generated for each year of the 20-year planning horizon. The only non-cash items included in the analysis were the salvage value in year 2O of added breeding livestock and, if appropriate, an estimate of any ranaining mesquite control value at the end of the 20-year horizon. all "before treatment" livestock production estimates, as well as projected changes following treatments, were obtained from the questionnaire . Results are presented for each vegetation region and include: (l) Annual rates of return. (2) Initial treatment costs. _ (3) Cost reduction required to yield an annual 9 percent return. (4) Average armnual net-cash flow. (5) Years required to break—even. (6) Average annual beef production per acre before and after treatment. An annual rate of retmn was estimated for the investment in added breeding livestock, brush management, and operating capital over the 20- year planning horizon. This rate is commonly considered an internal rate of return. The internal rate of »retu1n,'if used as-the discount rate in a. net present value analysis,would result in an accumulated net present value of zero for the 2O year cash flow. It ‘can be directly compared to interest rates charged by financial institutions,‘ and properly considers the timing and magnitude of all costs and returns over time. Since annual rates presented in this study are based on constant 1978 dollars, the analysis does not include the potential impact of inflation.- If it is deemed desirable to include an estimate of the influence of inflation, an assumed inflation rate can be added to the annual rates of return estimated for this study. However, addition of an estimated inflation rate assures that inflation will affect costs and returns equally and within the same time period. For example, an individual investing in long-term government bonds at 10.5 percent in 1978 at a projected 7 percent inflation rate actually realizes a 3.5 percent real rate of return on his investment. If brush management had no additional risk or imcertainity (compared with the bonds) the individual could invest in a brush management alternative that produced an anrmal 3 3 rate of return of 3.5 percent (as reported in this study) and be as well off in an econounlc sense. Since investment in brush management would likely represent an increase in risk and uncertainty, compared to investment in lorxg-tertn government bonds , a risk-return premium would be warranted for selection of brush management over the tmre secure investment. The aimuxit of this premium would depend on individual judgement in view of other opportunities for investment at the firm level. For this study, an annual interest rate of 9 percent was assumed to include a risk-retmnzn premium as well as the opportunity cost associated with the "next best" investment (such as the 3. 5 percent government bond example). It could be argued logically that assignment of a "constant" premium for risk and uncertainity is unrealistic. For example, the risk associated with reseeding projects are usually considered greater than with aerial spraying. However, since no comparative, reliable estimates of risk were available, a uniform annual interest rate was used. The magnitude of the initial treatment cost reduction that would be required fran a given practice to result in an return of 9 percent is presented.- This cost reduction can be used to determine the precentage reduction in initial cost necessary to achieve an annual 9 percent retmn. No particular emphasis should be given to the 9 percent value except that it A was assumed to represent a realistic level of return to compensate a producer for the added risk and uncertainity expected from brush management, If an individual accents the annual projected rate of return (internal rate of rent-n) diSCUSSEd earlier, no reduction in the initial treatment cost would be necessary. Initial treatment cost reported in the study includes implemen- tation of brush rrnnagenaent. ' Maintenance (followup) treatment costs, 34 also included in the analyses, were the same as initial costs for all broadcast herbicide treatments, but were generally less costly for mechanical treatments. Added investment in breeding livestock was included in the analysis but was not reported as part of the initial brush management cost. Calculation of annual average net cash flow allows evaluation of the influence of magnitude of investment and rate of return on funds avail- able at the firm level following adoption of a selected alternative. Since the timing of the cash flow was not considered, two treatments that produced different annual rates of return could have similar cash flows (even with a similar magnitude of investment). Determining the number of years required to recover the initial brush control costs and added investment in breeding livestock allow identifi- cation of a potential breakeven period. This criterion often becomes extremely important when lending institutions are involved in funding brush management. A practice that produced an acceptable rate of return might not be adopted if a shorter payback period were required, unless cash flows were adequate from other ranch activities, or from other sources, to pay back the investment. Generally, lending institutions require a relatively short payback period for brush control (less than 5 years in nany situations). However, it is possible to utilize longer- ternacredit sources, such as the Federal Land Bank, to borrow against land value for financing range improvements. The average weaned calf production response allows estimates of potential increases in beef production from alternative practices in each major land resource area. Pretreatment production estimates are included to allow percentage increases to be evaluated. Identical livestock production responses were assumed following use of 2,4,5—T, silvex EZ-(Zflfi-trichlorophenoxy) propionic acidl, 2,4,5-T + dicamba or dicamba for honey mesquite control. The 2,4,5-T + picloram mixture re- sulted in somewhat higher production responses than other herbicides primarily because it controls a broader spectrum of associated species, and has a longer average treatment life than that of the other chemical alternatives . Factors Influencing Selection of Alternatives Since various environmental and managerial variables influence responses to brush management practices, no specific practice can be uniformily judged superior for every situation. Consequently, two resource managers may make correct decisions and not choose the sane practice for similar management situations. For example, assume the use of a given herbicide produced an annual return of l5 percent compared to another alternative which produced 9 percent. If capital was not limiting and an individual would accept 9 percent as a annual rettnn, he might choose the "lower yielding" practice if risk conditions were different or if it allowed investment of more total funds which, in turr1, would provide a greater absolute net return than could be realized from the higher armual return investment. If investment capital is limited, the correct decision is usually to choose the practice with the highest irate of return for a given level of investment capital which is above the individual risk-return preference. Potential inxpact associated with the size of the operation also influences decision-making when selecting brush-management alternatives. 36 About 93 percent of all ranch firms in Texas which sell 2,500 dollars or more livestock annually operate with herds of less than 200 cows (Table 3). These firms are maintaining 63 percent of the State's breeding herd. The remaining 37 percent of the State‘ s breeding herd is maintained by 7 percent of the ranch firms which operate with herds of more than 200 cows. As ranch firms decrease in size, they can be expected to experience greater cash flow problems, since fewer "surplus dollars" are available for paying off range improvement loans after meeting consumptive needs. RESULTS The relative importance of honey mesquite as a management problem varies within and among the vegetation resource areas of the State. Therefore, it is imperative that basic differences in the vegetation, soils, climate, and rmige livestock production systems among these areas be considered when assessing the honey mesquite problem. High Plains The High Plains encompass about l9 million acres in extreme northwest Texas (Figure l) of which more than 7 million acres is used as rangeland (Table 1). This high tableland is essentially level and dotted with playa lalws- The elevation is 3,000 to 4,000 feet and the annual frost- free period is 180 to 230 days. Average armual rainfall is l4 to 2l inches, and rangeland is typified by short grasses such as buffalograss (Buchloe dactyloidg) and blue grama (Bouteloua ggacilis). Honey mesquite is the major brush problem in association with sand sagebrush (Artemesia filifolia) , cholla (Qptuntia imbricata), yucca (Yucca glauca), and sand 37 .moNwm :N oom.~w NmmoN pm w=NuNomoN mENNm Ncmmoammp mo:Nm> Q .som .mom .:oom ..Nw< .@@= .m.: .wNm>Nmcm Nwou NmEN:@ Name MOM m=oNw@N :oNpu:won@ .@N:pN:uNNm< mo wsmcmu ¢NmN “%HOuC0>GH mwmou wcm m@>Nwu .@NNNmu Eosm m@:Nm> >NoN:o>=N N N ¢N N N. NN N¢ ¢¢N cc. mN@.oN NNN.m mNn~oN oNnNm w mw wN cm QN mm m.N ¢.¢ w@N.N wmw mouwm m=NN+ N @N N NN Gm N@ ¢.@ N.@ N@Nu wmxoh .moNNNmnm w:mN |xumNm .w@NnNma@ wcmpo N NN M NN om N» N.@ o.m m@N.¢ vww moNNNmN¢ Nmnwcwu cwnoz .mnonENP wmoau N. NN m oN om ww N.mN N.m ~NN.oN @Nm m=NmNm wom w:NNNom .m=N@NN w:NNNoz N mm N mN Na Nm <.m, @.w @NN.@ mmw m:NmNm =NN= mENNw mzou NENNN mzou .mEHwM mzou mENNw wzou wENNw Nwwcmmsosuv ¢Qhm oohsomow comma wmom comma wwom sucmm moon zucwm mwom :uc¢¢ wzou Noon n=wN HO@m2 +¢¢m @@<-¢¢N maN|N NNV @N@Nw ¢~ N m»@@E=z Nmsmnesc ®~HHmUw :oNp:nNN~:ou QNNN @N@; Np NNV :oN~:nNN~mNQ wN@~QN .m.mX®P CM @096 wonsowoa NvcmN HO.MGE W300 M003 Q56 wEsNm SUCQH ‘#0 COfiPHNDNTHHwNZu, QNMw QQHNEMHWM QAQNP a Shirmery oak (@er¢u$ hgvafdii) _ The High Plains is typified by upland soils with slow-to-moderate drainage, primarily dark brown to reddish brown, mostly deep , neutral to calcareous clay loams , sandy loams, and sands . Cow calf operations are the most ccxrmon ranch enterprises on the High Plains which supports about 8.5 percent of the State's cows and of the ranches in Texas (Table 3) .e Only about 2 percent of the ranches support more than 500 beef cows with 9l percent of the operations having fewer than 20o cows‘. g About 48 percent of the rangeland on the High Plains is infested with honey mesqmiite (Table l). Although mere than half of the infestation is represented by light canopy cover, the moderate to dense infestations occur primarily on the sites with highest production potential. Based-on an annual survey conducted by The Texas Agricultural Extension Service (Hoffman, l978) , from 1973 through l977 an average of 63,752 acres were treated annually with chemicals for brush control and an average of 28,253 acres were treated by mechanical methods . Based on a comparison of the most commonly-used brush management alternatives on deep soils on the High Plains, the highest annual rate of return exceeded 9 percent and resulted from aerial applications of 2,4,5—T (Table 4). If 2,4,5-T and all herbicide combinations containing 2,4,5-T were eliminated, only dicamba would rennin as a registered chemical alternative for honey mesquite control. Shifting to dicamba reduced annual rates of return to 4.5 to 5.5 percent. Because of the higher cost of dicamba treatment, the shift would also increase capital requirements k by 45 percent, compared to 2,4,5-T (Table 5). The treatment sequence, root plowing-roller chopping-seeding, and maintaining range improvement by power grubbing produced a 2.9 percent Table 4. Annual rates of return (%) for honey mesquite contol on deep soils based on a cow-calf operation and $44/cwt cattle prices (1978 dollars) over a 20-year planning period in the Texas High Plains. Mesquite canopy cover and initial carrying capacity _ b (acres/AU/yr) Treatment ‘Moderate Dense Initial Maintenance (36) (41) 2,4,5-T 2,4,5-T 9 4 9.5 2,4,5-T + dicamba 2,4,5-T + dicamba 8 l 8.4 Dicamba Dicamba 4.5 5 5 2,4,5-T + picloram 2,4,5-T + picloram 5.4 5 0 Tree doze Grub 2.7 2 3 Tree doze-seedc Grub 2 4 0.7 Tree doze-roller chop-seed Grub 1.9 -- Root plow-roller chop-seed Grub -- 2.9 Typical counties Oldham Lynn 39 The rate of return considers all operating and investment capital in brush control and breeding livestock. constant 1978 dollars. costs and returns equally. Costs and returns were projected in Thus, annual rates of return do not include infla- tion impacts and are considered a real rate of return. market or nominal rates of return may be made by adding tion rate to the real rates. All herbicides aerially applied at 0.5 lb/acre. Seeding with native mixture of adapted species. An estimate of an assumed infla- This process assumes inflation will affect 40 u m 5 .mo@uomm wopmmwm mo opzwxfie o>@~m: zwfiz wcfiwoom u .@~U@\@H m.o pm wwflfiggm »H~@@~@@ mwvflufigpwz -< @ .mom:oQxo cofiumnomo wcw .m~mE~:m w=@@@@~@ wowmopucfi .~oa~cou smsun cfl wowm@>:@ Hmpflmmu wownm ~Hm MOM @w~@;@ wmwgowcfi wm m mme:mmm.ms~w> ucowonm um: ash .w~:oE~mo>=@ xuopw@>@~ w:@w@m~n mn:Huc@ Ho: on mpwou wcmspmwwu ~m@~H:~ m ccxq Em:U~O mofipczou _@@H@>+ mH.w~ oo.om 1| || nsnu unmom|mo:u no-oa|2o~m poem || 1; mo.- oo.mm nswu uuwom|mo:u noH~on|m~ow woak @@.¢~ oo.mm ¢@.¢H oo.m~ nsau Q@@@m-@NQ@ omnh ~m.- ¢Q.- om.o~ oo.o~ Qzgw @N¢@ ownh m~.m m~.@ ~m.m m~.@ emhofiufig + @-m.¢.N Ewgofiofim + P-m.¢.~ ~o.m cm.~. @@.~ ¢m.~ mnamufio mnemufia m¢.¢ mm.w mm.o mm.m wpemufiw + h|m.¢.~ mnsmofiw + e|m.w.N ¢ ¢w.w Q ¢m.m @-m.<.~ @-m.<.~ cowuuswoa “moo cofiwuswwa pmou oucmcowcfiwz A ~m@p@:~ pmou flmfiwwmw uwou ~m@w@:~ npcoswmope ~_¢v A@mV A: omcoa uwmauwoz ~a>\:<\monom~ xumummmu w=@>-¢o ~m@u@:@ can no>ou >@ocmu opfisvmoz .m:@m~@ M aw“: mmxoh ms» co wofiamm w=~==¢_@ nmo>»o~ m wo>o woofinm wfiwpmu w2u\v¢w ccm cofipwnomc wfimuizoo m so ummmn m~@om moon co ~m~m-on w~a~V xuo~mo>@~ wcfiwwmnn vomnm wan ~o-:ou owfisvmos xocoz cfi ~:oEpm@>:M map so cpspoa mo owma fimsccm wm m @~@fi> ow @@~@=¢@~ ~mpum\%v cofluuswon pmou wcm wwmoo ~:oEwmo~p ~m@pH:~ .m wfinmk 4-1 annual rate of return, the highest of the mechanical brush management systems on deep soils (Table 4). However, the capital requirement for the root plowing-based system was nine times that of aerial spraying with 2,4,5-T (Table 5). All honey mesquite management approaches, except aerial spraying with 2,4,5—T required reduction of initial costs to achieve a 9 percent, annual rate of return (Table 5). Use of the "next best" chemical alternative to herbicides containing 2,4,5-T, dicamba, would require an average cost reduction of 3.00 dollars per acre if cattle prices were maintained at 44 cents per pound. However, substituting half of the 2,4,5—T with dicamba would require cost reductions of only 1+5 to 53 cents per acre to yield a 9 percent rate of return, based on 1978 costs. Cost reduction requirements for mechanical practices ranged from lO.5O to 28. l5 dollars per acre to generate a 9 percent annual rate of return on the investrrent. Annual net cash flow increases were estimated to be 54 to 72 cents per acre for aerial applications of 2,4,5—T if l978 cost/prices were maintained (Table 6). Net cash flow was projected at 23 cents per acre per year less if dicamba was aerially applied than when 2,4,5—T was selected. Annual net cash flow increases for all mechanical methods on deep soils of the High Plains were positive with greatest net cash flow (l.36 dollars per acre) resulting from root plowing-roller chopping-seeding and maintaining range inprowrexrent ? by power grubbing. Tree dozing maintained by power grubbing increased the annual net cash flow 42 to 47 cents per acre, regardless of honey mesquite canopy cover. Tree dozing and artificially seeding the pits increased annual net cash flow 21 cents per acre on sites with dense canopy cover and 54 cents per acre on sites with moderate canopy cover. The pay-back period ranged from ll to more than 2O years (Table 7), indicating problems in financing brush management practices by ranchers on 42 Table 6. Increased annual net cash flow ($/acre) following control of honey mesquite on deep soils based on a cow-calf operation and $44/cwt cattle prices (1978 dollars) over a 20-year planning period on the Texas High Plains. Mesquite canopy cover and initial carrying capacity b (acres/AU/yr) Treatment Moderate Dense Initial Maintenance . (36) (41) 2,4,5-T 2,4,5-T 0.54 0.72 2,4,5-T + dicamba 2,4,5-T + dicamba 0.49 0.67 Dicamba Dicamba 0.31 0.49 2,4,5-T + picloram 2,4,5-T + picloram 0.53 0.48 Tree doze Grub 0.47 0.42 Tree doze-seedc Grub 0.54 0.21 Tree doze-roller chop-seed Grub 0.61 -- Root plow-roller chop-seed Grub -- 1.36 Typical counties Oldham Lynn The net cash flow is total added cash sales ($44.00/cwt) less costs of brush control, added breeding livestock and increased annual operating costs plus the salvage value of cows and brush control (if applicable) Interest charges were not at the end of the 20-year planning horizon. included and the timing of cash flows was not considered. Native mixture of adapted species. All herbicides aerially applied at 0.5 lb/acre. 43 Table 7. Years required to recover initial mesquite control and livestock investment on deep soils with a cow-calf operation and $44/cwt cattle prices £1978 dollars) over a 20-year planning period on the Texas High Plains. 2 Mesquite canopy cover and initial carrying capacity b (acres/AU[Yr1 Treatment Moderate Dense Initial _ Maintenance (36) (41) 2,4,5-T 2,4,5-T 12 11 2,4,5-T + dicamba 2,4,5-T + dicamba l2 l2 Dicamba Dicamba 20 + A l8 2,4,5-T + picloram 2,4,5-T + picloram l6 20 Tree doze Grub l9 19 Tree doze-seedc Grub A 20 + 20 + Tree doze-rgller chop-seed Grub A 20 + -- Root plow-roller chop-seed Grub —- 20 Typical counties Oldham Lynn a A 20-year planning horizon was utilized and no interest charges was included. The time period represent a "pay-back period" commonly used to evaluate investment opportunities. Salvage values of cows and brush control (if applicable) are not included as part of the pay-out period, but would represent gross returns to the operation at the time of "pay-back." A 20 + indicates greater than 20 years will be required to recover the investment. b All herbicides aerially applied at 0.5 lb/acre. Native mixture of adapted species. 44 the High Plains if surplus cash flows were not available from other activities by the operation. Pay—back period for aerial application of 2,4,5-T or 2,4,5-T + dicamba was ll or 12 years but was l8 to more than 20 years when dicamba alone was applied. From l6 to 20 years were required to pay back the investment in 2,4,5-T-+ picloram,and pay-back period for mechanical methods rangedfrom 19 to more than 20 years. Potential increases in livestock production fronxmesquite control on the High Plains ranged from 42 to 126 percent (Table 8). Since site potential was the same, there was little difference in potential weaned calf production after treatment for either canopy cover situation. Honey mesquite control with herbicides increased weaned calf production to l3.7 pounds per acre per year, compared with 8.9 to l0 pounds per acre annually on brush-covered rangeland. Tree dozing did not increase weaned calf production.ctnpared to spraying, except when the pits were seeded on sites with moderate canopy cows: or when tree dozing was followed by roller chopping and seeding. Highest weaned calf production, 21.2 pounds per acre per year, occurred following the root plowing-roller chopping and artificial seeding inprovement sequence. In order to develop comparisons annng the honey mesquite alternatives, cattle prices were projected to average 44 cents per pound over the next 20 years based on 1978 prices. Obviously, any changes in cattle prices and/or associated production costs will alter the economic responses used as criteria of comparison. Moreover, it would be impractical to attempt analysis of a range of cost/price situations because of the *' number of resource regions and associated production situations. However, changes in net cash flows and annual rates of return within a range of cattle prices from 34 to 54 cents per pound can be estimated from data presented here. Table 8. Total weaned calf production (lb/acre/year) following hogey mesquite control on deep soils on the High Plains of Texas , 1978. Mesquite canopy cover and initial carrying capacity (acres/AU/yr) Treatmentb Moderate Dense Initial Maintenance (36) (41) None (pretreatment) 10.0 8.9 2,4,5-T 2,4,5-T 13.7 13.7 2,4,5-T + dicamba 2,4,5-T + dicamba 13.7 13.7 Dicamba Dicamba 13.7 13.7 2,4,5-T + picloram 2,4,5-T + picloram 14.4 14.2 Tree doze Grub 14.1 13.5 Tree doze-seedc Grub 16,5 14,4 Tree doze-rgller chop-seed Grub ' 18.2 -- Root plow-rgller i chop-seed Grub -- 21.2 Typical counties 7 Oldham Lynn a Production responses over a 20-year planning period. b Herbicides aerially applied at 0.5 lb/acre. C Native mixture of adapted species. 46 Average cash flows per acre can be adjusted by multiplying the net increase in beef production per acre by the amount of price change and adding or subtracting the result from the 44 cents per pound situation. For example, assume that 50 cents per pound was considered realistic and tree dozing and seeding was to be evaluated. The average annual net increase in.beef prodction per acre for this practice is estimated to be 6.5 pouds per year (16.5 - l0.0 ) (Table 8). The change in price, 6 cents per pound (50 - 44), multiplied tines the anual production increase (6.5 pouds per acre) results in a projected 39 cents per acre per year increase in value from the 44 cents per pound price situation. This value sumed with the value reported for a cattle price of 44 cents per pound, will yield the net annual average cash flow increase for a 50 cents per pound situation. For the tree dozing and seeding alternative, increasing the cattle price from 44 to 50 cents per pound resulted in an anual net cash flow increase from 54 cents per acre CTable 6) to 93 cents per acre. Annual rates of retun can be adjusted by multiplying the rate of retun adjustmentictor for a given honey mesquite alternative by the price change from 44 cents per pound and adding (or subtracting) it to the annual rate of return presented in Table 4. The rate of return adjustment factors for the price range, 34 to 54 cents per pound, for the High Plains are: Alternative Adjustment factor 2,4,5-T .54 2,4,5-T + dicamba .53 Dicamba .49 2,4,5-T + picloram .46 47 Tree doze .22 Tree doze/ seed .2l Tree doze/ roller _ chop/ seed . 24 Root plow/ roller chop / seed . 24 For example, assume that an estimate of the rate of return isdesired for tree dozing and seeding (given a moderate honey mesquite canOPY) when cattle prices are 5O cents per pound instead of 44 ‘cents per pound. The adjustment factor (0.21) is multiplied by the price change per knmdredvreight ($50.00-$44.00 = $6.00) yielding a value of 1.26 percent. This value is added to the annual rate of return when cattle prices are $44 per hundred- weight (2.4 percent from Table 4), yielding a total annual rate of return of 3.33 percent for the new cattle price situation. A reasonable accuracy of the estimate cannot be insured if livestock prices outside the range, 34 to 54 cents per pound, are used. Rolling Plains and Rolling Red Plains The Rolling Plains is often considered as mo distinct land resource areas; the eastern portion being often referred to as the Rolling Red Plains or "reddish prairie" because of the preponderance of reddish and reddish brown soils. This differentiation is based primarily on soils but differences in rainfall also occur. The Rolling Plains and Rolling Red Plains cover about 24 million acres of northwest Texas (Figure l). The Rolling Plains and Rolling Red Plains are broad, nearly level to rolling plains with moderate to rapid surface drainage. About 6O percent of the area is estimated to be in native range (Table 3). Elevation is 1,000 to 3,000 feet, and average annual rainfall is l8 to 28 inches with the Rolling Plains averaging l8 to 22 inches annually. ‘intermingled in various proportions depending on range site. 48 The anual frost-free period is 185 to 235 days. Upland soils are pale brown to reddish brown to dark grayish brown, neutral to calcareous, sandy loams, clay loams, and clays over reddish calcareous, loamy to clayey subsoils (Godfrey, Carter and.McKee undated). The bottomlands are ndnor , areas of reddish brown, loamy to clayey, calcareous alluvial soils. l The Rolling Plains and Rolling Red Plains support 9.2 percent of the State's beef cows and contain 13.2 percent of the ranches in Texas (Table 3). Only l percent of the ranches operate with 500 or more head of beef cows whereas 96 percent of the ranches have fewer than 200 beef cows and account for 78 percent of the cow inventory for the resource region. Vegetation is mixed grass with sodgrass and midgrasses (bunchgrasses) Honey mes- quite is the primary brush problem in association.wdiialotebush (Zigyphus obtusifolia) and pricklypear (Qpuntia spp.). The sandy soils support sandy shdnery oak, yucca, and sand sagebrush with scrub oaks (Quercus $pp) increasing in importance in the eastern portion of the vegetation region. Over 85 percent of the native range of the rolling Plains and Rolling Red Plains support a honey mesquite infestation (Table 1). During the past 5 years, herbicides have been applied to about 278,000 acres annually, and about 105,000 acres were treated per year with mechanical methods for brush control (Hoffman 1978). About 45 percent of the presnet honey mesquite infestation is represented by light canopy cover, a reflec- tion of past brush management efforts (Table 1). However, 42 percent of the infestation (about 5 million acres) have moderate to dense canopy covers on range sites of higher production potential. \ h 49 Rolling Red Plains. Econoic responses on the Rolling Red Plains were similar to those discussed for the High Plains. Regardless of site potential or canopy cover (and associated pretreatment carrying capacity) on the Rolling Red Plains, highest annual rates of return resulted from.aerial applications of 2,4,5-T (Table 9). Highest rates of return (15.4 percent) occurred from applications of 2,4,5-T to dense canopy covers of honey mesquite on deep soils. Annual rates of return from treating deep soils with a moderate canopy cover or from treating shallow soils were about ll percent. Although aerial spraying cobined with chaining has traditionally been a standard management system for dense honey mesquite stands on the Rolling Plains, annual rates of return were about the same as from spraying only (Table 9). Annual rates of return from dicamba, the only herbicide treatment not containing 2,4,5-T, ranged from 7.1 percent to 7.6 percent, except on deep soils supporting a dense canopy (10.8 percent). Highest rate of return from the mechanical practices, 10.5 percent, was generated by chaining followed by maintenance sprays of 2,4,5-T. The utility of this practice is limited primarily to areas supporting sites of honey mesquite plants large enough to be uprooted by the chain. Adjustment factors for evaluating annual rates of'return for cattle v prices ranging from.34 to 54 cents per pound for the various alternatives on the Rolling Red Plains are: Alt€fn&tiVe Adjustmnt factor 2.%,5—T 0.61 Z,4,5—T (chain) 0.63 Z,4,5—T + dicamba 0.59 Dicamba 0.55 2,4,5—T + picloram ‘ ' 0,54 .wnum\n~ m.o um wmfiflmmm >-mHsom ®h®3 mowfiuflnpwz .o~:~x@E mmmnm|@>Hpm: noummwm op wwmuozu .>-m:¢o mcnzpon new mumou puowwm -@3 :oHum~wcH moesmmm mmmoonm mfick no PQMHME mo mwmsfiumm c< ow caswoa mo mwpmn fimsccm .m::P .moums flmon map ow mama coflwmfiwcfi wmesmwm cm wcfiwwm >2 mums on xws cwspon we mmump fimcdeoc .:n:poa mo ouma fimoa m wwaonfiwcoo ohm wan mpummsfi :o@wm~w:H @w:~uc@ we: .mnm-ow w>m~ wcmpmcou GM wouuo@owm OM03 mcasuon wcm mwmou .xuopw |®>M@ MC@©®®H£ U56 AOHHCOU swans CH HGHMQNU HGOEHm0>C@ U56 MCwH@HOQO add wsowflmcou CHBHQH MO QHGH QSFM pcoz ~@w~@@~HHz w=@¥ o~puou moflwcsou H@@@@>@ -- ¢.¢ -- ~.~ ~Ho HHQ -- -- m.¢H m.@ P-m.<.~ ¢M@;u 1| || m.w w.m QJHU mmmnm:@o~x|3o~m poom ~.¢- ~.¢- m.m m.¢ Qzgw @@@w-;¢H@ pooz ¢.¢- ¢.~- @.¢ ~.m %@=~w @@@@w-@N@@ mmhb -- -- @.@- -- k-m.¢.~ @@@m-@¥m~-=fim;@ w.@ @.~ H.¢H m.w empofiuwm + P-m.<.~ emgofiufim + @-m.¢.~ @.~ m.~ w.¢H ~.~ mnemufic mpemufla ~.Q~ m.¢~ ~.¢~ m.¢~ @@e@Q@@ + @-m.¢.N mnamufiw + P-m.¢.~ ~.- -- m.<~ -- =@m;@ @-m.¢.N ~.- m.- <.mH m.H~ @-m.<.~ P-m.¢.~ hmqv fiaqv Am.mmV AQMV @Q=m¢@~=H@z ~@@p@=~ omcwc owmuowoz mmcoa oumnmnoz nucoewmonk wflfiom zoflfimsm w~@om move ->\=<\m@»u@H >~@ummmu wcwxnnmo fimfiwficw mam mpfim >2 »o>ou xmocmu owfisvmoz Q co nommm mcfimflm mum .wo@aom w=@==m~@ amo>|o~ m no>o ~mnm-ou w~m~v.mou@pm o~pumu u3u\wvw new cofiumwwmo w~mu|zou wcfiflfiom ocw co ~on~:ou wuflsvmms >020: EOMM fiwv canvas we wmumn ~m:::< .a oflnmk n . 51 Chain-rake—seed - 0.29 Tree doze-seed (native mix) 0.21 Root ploweseed (native mix) 0.l8 Root plowekleingrass 0.46 Chain 0. 50 Oil 0. 3O These factors can be used to adjust the annual rates of return for variation in cattle prices, within the stipulated range, as described in the example for the High Plains. Initial costs for herbicide alternatives on the Rolling and Rolling Red Plains were the same as those for the High Plains (Table 5). Initial costs for the mechanical brush management alternatives on the Rolling Red Plains ranged from 8.00 dollars per acre for chaining and maintaining improvement with broadcast sprays of 2,4,5-T to 80.00 dollars per acre for root plowing and establishing kleingrass pastures (Table l0). No initial cost reduction was required for aerial applications of 2,4,5-T, 2,4,5—T followed by chaining, or 2,4,5-T-+ dicamba to yield a 9 percent annual return to management for honey mesquite control on the Rolling Red Plains (Table ll). In addition, no initial cost reduction was required for dicamba or 2,4,5-T +-picloram.to yield a 9 percent anal rate of return when applied to dense honey mesquite canopies on deep sites. However, application of these herbicide a alternatives to the other honey mesquite/site situations required au cost reduction of 0.44 to 2.17 dollars per acre to yield a 9 percent annual rate of return. The only mechanical practice not requiring a cost reduction to yield a 9 percent return was chaining followed by appli- cations of 2,4,5—T to dense honey mesquite canopies on deep soils. The same treatment required a cost reduction of 72 cents per acre if applied 52 .mo@uomm wopmmwm mo oaswxfie mmanw|o>Hum: ow wuwmom u Q iuowmo>z MCMQQQHD owsfiucfi HOG Ofi mwmou HGQEHMOHH AUMHHCM w .onom\n~ m.o pm wo@~mmm xfifimfiaom monwofinaoz uflmz aowamnfifiz w=@¥ wfiupou mofiwcsoo ~@uH@>@ -- o¢.¢~ -- Qm.~N fifio ~@Q 1| -1 oc,w oo.w @-m.¢.~ =H¢;u || 1| oo.ow oo.om nsnu mmmnw:Ho~x|3o~m uooz ¢m.- cm B@ ¢¢.¢@ Q¢.¢m @=~u Q@@@m-3¢~@ ~¢o¢ oo.m< om.~v oo.ov oo.cw @=~@ Q@@@m-@~¢@ woke '1 -1 oo.cm 1| P'm.¢.~ uwwom|oxmn|:@m:u Amwv .¢¢. ~m.mmV flow - @Q=@=@~=@@z ~@@@H=_ omcma . owmsmnoz omcoa mwmpwwoz . nwcvépmosb mfifiom zofifimsw mfifiow move ~a»\:<\woaomv >u@ummmo mcwxnnmu ~m@p@:@ mam oumm >@ no>ou xmocmu opfiswmoz @.w~@~ .w=@@~@ wmx m=@HH¢¢ m¢x@P @=~ =¢ H¢-=¢u oufisvmoe xococ wow wofiflmmm mm>@~m:no-m wcoaowmcms swsan nuwooflow mo ~o~um\wv mwmou ~@@»fi=H .oH ofinmk 53 .mo@oomm wwwmmwm we mpzwxfis mmmnw|@>@pm: ow muowwz .mnum\n~ m.O um fiwfiaflflm >-m@nmm mmwfiufingos ~H< U n .mow=omxo zoflumammo wan .m~mE@:m wcfinomnn nommwaocfi -OHHGOU £mDHQ Cw wo~w@>:fi ~m~@mmu wanna Hfim now mmwmcu pmonowcfi wm m moasmmm o:~m> pcwwonmlpoc use Q w=@¥ G ucoz pwmgmgfifiz ofipuou moflwcsoo fimufimxw 1| w¢.¢~ 1| o~.N~ fifio fifio -1 || o -.¢ @-m.¢.~ =@@;@ || || w~.¢¢ mc.om nsau mm@~w=@@Hx-=oH@ uoom <~.¢m @H.¢m mw.mm >m.m~ nzuu Q@@@m-zoH@ poem m~.@m ~@.¢m @m.>H >~.- nsnu U@@@m-@N¢@ oonk '1 1| -.¢~ 1| @-m.¢.N U@@@m-@¥@»-=@@=Q >H.~ -.~ ¢ <¢.¢ amgoflofim + @-m.<.N EQHQHQHQ + P-m.¢.~ m~.~ m~.~ o ~@.~ mnemufia mnemufio o o Q o mnemufiw + P-m.¢.~ Qpemufiw + @-m.¢.N o -1 c -1 =H@=u @-m.¢.~ ¢ ¢ Q @ @-m.<.~ @-m.¢.N fimqv A@\m<\mw~um~ xudummmo w=@>-@Q Mwfiuficfi wcw ouflm >@ »o>ou xmocmu owfizcmoz .wwm~ .m:@m~m mom m:@-oz mmxwk wan :0 nofiaom w=fl==@_@ umo>|cN m ~o>o mouflam ofiwumu w2u\@~ mcfiwoonn wonnm was ~o~wcou ou@:¢mo&.>o:o: :H u:oEumo>:@ 0:» :2 SHZHUP HO mums dmzccm mm m mcHn~o@> HO% wmnwflvon ~onom\%v cofiuosuoa umoo ~m@u@:H .- QHQMP 54 to moderate mesquite canopies on deep soils. Cost reductions for other mechanical practices to yield a 9 percent annual rate of return ranged from 12.76 to 54.24 dollars per acre. Increases in estimated annual net cash flows varied widely among the honey mesquite control alternatives on the Rolling Red Plains (Table 12). However, annual cash flows associated with aerial application of 2,4,5-T, 0.81 to 1.32 dollars per acre, were consistently higher than the herbicide alternative not containing 2,4,5—T. Aerial applications of \ 2,4,5—T followed by chaining increased anual net cash flow by 0.77 to 1.52 dollars per acre when applied to dense canopy covers of honey mesquite. iDicamba increased annual net cash flows by 0.65 to 1.06 dollars per acre depending on the specific honey mesquite/range site situation. Applied to honey mesquite on deep soils, 2,4,5-T + picloram resulted in increased annual net cash flows similar to those from 2,4,5—T alone. This response was attributed to the slightly longer effective average life of the 2,4,5—T/picloram combination and improved weed control, compared to 2,4,5—T alone. Where mechanical treatments were applied to shallow soils, annual net cash flows ranged from a -34 cents per acre to + 7 cents per acre (Table 12). However, on the deep soils, mechanical practices increased the anual net cash flow and, in.most cases, the increases exceeded those from herbicide treatments. Greatest increases in annual net cash flow, 4.34 to 5.49 dollars per acre, were generated by the most intensive alternative, establishment of kleingrass pasture. Increasing ~ aual net cash flow, if the annual rates of return are above an operators ndnimum acceptable level but less than other alternatives, is one motive for selecting mechanical brush control practices over other alternatives. 55 059 UGM fi®U3~UCM HOG 0903 wowamco HWQHOHCM .m0@oomm nowmmwm we wuswxfie o>H~m= ow m~ow@m .onuw\nH m.o um wo@~mmm xfifimqnwm mowflufinnmc -< .wo~owHw=ou po: mm: mzoflw ammo mo mcflefip .coN@»o: mcficcmfim »@@> ow ocu we cam mcu pm Ao~nmuHHmmm mfiv ~onu:ou smsan wan mzou mo o:~m> omw>~mm ecu mafia mwwou w=H~@~@@¢ ~m:::m wommonucfi wan xuopwo>H~ wcfiwmoan nmuwm .~o~p:ou swans mo mpmou wmo~,-3u\oo.w¢wv mm~wm.:mmu wvuwm fimpow ma 2o~w ammo yo: oak »=@¥ ~@@»@@~H= m=@¥ @H~pou wmflpzsou ~@QH@>P |» ~o.o || m¢.o ~@o flfio 1| || om.~ @@.¢ @-m.¢.~ cwmsu 1| || ¢m.< mv.m nsnu wmmnmcfimfix/2o~m uooz @@.¢- ¢H.@- @~.~ om.~ Qzpu Q@@@m,=¢~@ pooz ma.©| Qm.@l , £.:.H@ UQvQQW/QNOU 0.0%.? 1| l» mo.o| -1 @-m.¢.~ u@@@m-@¥@~-=H@;Q mw.o o~.o m~.~ mm.o Emnofiufim + P|m.¢.~ Ewao~u@m + P|m.v.N ow.o mo.c oo.~ ~@.¢ mnemofig mnEmu@Q ww.¢ >~@¢ @N.H ~w.¢ mpemufiw + P-m.¢.~ Qpemufiw + P-m.¢.~ -.¢ || Nm.~ -1 cfimsu P|m.¢.~ ~@.¢. ~w.¢ ~m.H No.0 P-m.¢.~ P-m.<.~ fimwv AQQV ~m.mmV momv oucmcowcfimz ~m@p@:~ omcoa opmnowoz owcoa oumamwoz ucmepmonb m~@om 2o-m:m . wfiwom mama n>\:<\wonum~ xpwummmu wcfixaamu ~m@u@cH wcm owfim >2 ao>ou >mo:@u oufisvmoz .w~@H Q .mc@m~& wom wcflfifiom wmxoh ecu co Awnmflfiow w>m~v moufism o~p~mu u2u\www was :o@pwnmQ©Jw~mu|2ou m co wwmmn m@>@~m=~@-@ ~o»~=oQ opfisvmws zone: wouuofiwm EOPM ~o~um\wv zoflw ammo Ho: fimsccw vmmmmao:~ b. .N~ wfizwk 56 Again, the decision to select a given alternative for a selected management unit is influenced by overall financial requirements of the ranch firm. If past investments practices which yield a high annual rate of retmzn have been installed on other management units, the manager may option to install a practice which may be complementary in nature to established practices and will significantly increase net annual cash flow through the operation Such an approach, of course, assumes that investment capital is not a limitation and mlinimum rates of return are achieved. Time required to recover the initial investment in aerial appli- cation of 2,4,5-T or 2,4,5-T followed by chaining for honey mesquite control on the Rolling Red Plains ranged from 7 to ll and l2 years, respectively (Table l3). Nine to l3 years were required to recover the initial investment in aerial applications of 2,4,5-T + dicamba and l0 to l5 years were required for recovery of‘ the initial investment in applications of dicamba. Because of the relatively high initial cost (Table 5), l2 to l6 years were required for recovery of the initial investment in aerial application of 2,4,5—T + picloram1 (Table l3). On shallow soils, more than 2O years were required to recover the investment in the selected mechanical alternatives for honey mesquite control on the Rolling Red Plains (Table l3). Chainirmg followed by application of 2,4,5-T. required lO years for recovery of the initial investment, similar to the, time requirement for recovering the investment in 2,4,5-T alone applied to the same sites. These responses illustrate the importance of site selection based on product ion potential for range improvement activities . For example, root plowing or tree dozing followed by seeding a mixture of native range grasses on soils required l6 to l9 years for l recovery of the initial investment, even on the more productive sites (Table l 57 .mowoomm UQHQNUQ W0 QHDHXME ®>wH6Z .0HUm\£@ m.O um UQXNHQW xH~m~nom mowwufinnws -< .u:oEpw@>:N oz“ M®>O00H op wopfizwoa on HHNz mnmox om cmsu aowmwaw wo~muNw=N + ow < :.xomn|>wm: we oefip osu pm coflpwwomo mag ow mcaspwa mwoum ucomonmon nH:o2 was .woNnm@ ~:o|>wm oz» mo pawn mm wow:Hu:@ Ho: max ~oHnmoNHmmm wfiv Hoaucou :m:Hn mam mzou mo mo:Hm> omm>Hmm .wwH@N::unommo pcoEpwo>=N opm:Hm>@ ow wow: >HcoEeoo :woN~om xuwn|>mm: m wpcmmwnmon wofinom mafia one .wow:~u:N ohm momamsu umoaop:N oc new woNNHN»: mm: coN@no: N=H=¢@H@ Nam» xwcmzu < m H=@H aownmn~@2 N=H¥ ofipwou mofiwcsou Hmuflmxe -- + QN -- QN HHo HHQ -- -- QH QH P-m.<.N =H@=u || 1| ow NH nsau mmmam:NoHx|2oHm woom + ¢N + ¢N mH wH H=HN Q@@@m-:oH@ HQQN + ON + ON ©~ mm .D5HU U©®®m|®NOU QQHP -- .-- + @N -- h|m.¢.~ Q@@@w-@H@N-=HN=u @H @H NH mH ENNQHQHQ + @-m.¢.N EmNoHuNm + @-m.<.N ¢H mH QH NH NHENQHQ NQENQHQ NH .mH N HH NHENQHQ + @-m.¢.N @@EN@H@ + @-m.¢.N HH -- N -- =H@=u P-m.¢.N NH N Q QH @-m.¢.N P-m.<.N HNQH HQNH Hm.mNH HQNH @Q=@=@H=H@z HmHHH¢H owcwc QHMHQUOZ omcoc QHQHOUOZ HCQEHMQHP m~@om 2o-m:m mHNom mmon An>\:<\monomv . zufiummmu mcfixanmo Hmfiuficfi wcm mufim >2 ~o>ou xmocmu ou@:vmo: 6 G GO OQWQD HC®EHWQ>CH ¥UOHm0>H4 U56 #OHHCOU QUAD .®B@@ .m:Hm~a UOM MCM-OZ MNXQP USP GO ~mna-ow whmaw WQUMMQ QaHH@U H3U\¢¢% fiiw COMHNHQQO W~@U|3OU UWQE XQCOC MMHHHCH P®>OUQH OH UQMADUQH mH®®> .n~ wanna. 58 . Qmua. am.‘ Applying the same treatments to shallow soils caused the time to recover the investment to exceed the 20 year planning horizon. Although 20 years werezrnwdarxifor recovery of the initial investment in establishing kleingrass on deep soils supporting dense canopy covers of honey mesquite, only l2 yearsvmnearequired on sites supporting moderate canopy covers. Average annual production responses were similar among herbicide alternatives ranging from 18.0 to l9.3 pounds of beef per acre on the deep soils with greater responses following application of 2,4,5-T + picloram than from 2,4,5-T, dicamba or 2,4,5-T + dicamba mixtures 1 (Table 14). Greatest annual average production response, 62.8 pounds of beef per acre, occurred where tame pastures (kleingrass) were established following root plowing. Revegetation projects utilizing native forage mixtures following tree dozing or root plowing were estimated to produce from 23.8 to 27.8 pounds of beef per acre per year for the 20 year planning horizon. Rolling Plains. Annual rates of return from aerial applications of 2,4,5—T on the Rolling Plains varied from 12.7 to 16.9 percent on deep soils, depending primarily on site potential (Table 15). Rates of return from honey mesquite control on deep soils on the Rolling Plains were some- what higher than on the Rolling Red Plains, apparently because of somewhat higher rainfall. However, annual rates of return were lower on shallow soils of the Rolling Red Plains (Table 9) than on the Rolling Plains (Table 15). This differential was attributed to higher initial carrying capacities on the shallow sites of the Rolling Plains which reduced the 4 potential production change following brush control, compared to the Rolling Red Plains. Application of 2,4,5-T for honey mesquite control on shallow soils of the Rolling Plains varied from 4.1 to 7.9 percent. Annual .om=omwo~ .mowu0@m nowmmwm mo QMDHXME @>@pmz u .onum\n~ m.o um ww@~mmm xfifimflamm mowfiufinaoz n cofiwuswoam @m@~@>@ mcfiepmwon op woN@~@~: mm: nofiaom wcficcmfim nmo>|o~ < w mmwpcsou ~@@@@>F fific =H¢;u mwm~m:Ho~x»2o~m poem owoom|2o~m poem uwoow|oNow oogh uw@om»oxma|:Mmcu Emnofiufim + e|m.¢.N wnemufia mnemufiw + P|m.¢.~ P|m.¢.~ @-m.<.N Auzmeumonuopmv ocoz wcox ~@m~@@~@: w=@¥ odppou -- ~.¢~ -- H.@~ flmc -- -- <.wH m.@H @-m.¢.~ -- -- ~.mm w.~@ @=»@ w.@~ ~.@H @.@~ w.- Qzgw @.¢~ m.<~ w.m~ m.m~ Qshu -- -- N.@~ -- P-m.¢.N @.¢~ ~.¢~ m.w~ m.@~ Emgofiuflm + @-m.¢.~ ¢.m~ @.m~ @.wH ~.wH @@E¢QM@ ¢.m~ @.m~ @.w~ N.wH wgemofiv + @-m.¢.~ ¢.mH -1 m.@H -- =@@;u ¢.m~ @.mH ¢.@H ~.w~ @-m.<.~ @.w ~.@ N.- m.- Amvv Aoqv fim.mmv HGMV @u=@¢@~=H~z omcoc QHQHQUOE wwcoo oumnmuoz Q mflfiom 3o~Hm:m . wH@om mmoo ~n>\:<\moaomv xpmummmu w=@>-@U ~m@pHcH wcm oufim >@ ao>ou xmocmu owfisvmoz G M CO UQWQQ ~OHHCOU QHHD ’ ~m@u@:H ucwswmoae .w~m~ .w:@m~@ mom mc@-om mmxoe map co fiwamflfion w~m~v woofinm o~ppwu p2u\v<@ wcw cofipwaomo w~mu|2ou vwoe xocos nowuo~ow EOHW ~pmo>\onum\n~v cofipusmopm wflmu nocmoz flmpok .v~ Qfiamk \I 66 H. i moesmwm wmeeepm mesh flmcfisec no eexnms we owmsfipwe c< we: on cnswwa we moemn flmsccm .m:cP .me@eemm wowmmem we en:~xH=_ e>@emz ‘ .enem\n~ m.c em @@H~ee@ >-m@~em mowfiefingez H~< .>-@=¢@ mcpseon ecm mewee eeemmm -~2 :eH~w~w:@ .meum» fieea use ow ewmw :e@~m~wc@ eesswwm cm wcfiwwm >@ meme on xms cnspon we meems .ca:eoa we even fimea m eowecfimcee one wcm weemmefi :e@em~m:@ eezfiecfi .m~m-ew wwmfl pcmemcee ed eepeeweam eaez mcwspen new mpmeu |o>@~ wcfiweean new Heaucee sweep cfi Hmefimme ecoEewe>c@ new mcfiweaeme -m waewfimcee cwseea we owe» oak .xeeum m=flH~@em Qxoe Hem: mcexefia :m:e-mu >e~cee me@u::ee ~@eHe>@ -- -- w.¢ ~.m H.w @.@ Qsee mm@~w=e@H¥-3o~e pea“ -- -- N.m @.~ e.~ ¢.N Qzpe ewmwm V lmece ne-en|2o~m poem || || 1| || v.~ || H|m.w.N woom|2eHQ weenlmfimew ¢.~ m.H- H.~ ~.~ ¢.m m.H Qzhe @@@m-@No@ @@~e @.~ w.¢ ~.m ¢.< w.m @.~ @=~e @@@@m-z¢~@ eaoz -- -- e ~.> B.¢~ H.- -- @-m.<.~ =e@=e -- -- .QIN m.H ~.~ m.~ @-m.¢.~ Ue@@m-@No@ Que? -- -- ~.~ @.m ¢.N m.¢ P-m.<.~ e@@@w-zQH@ poem -- m.@- m.¢ -- -- m.¢ E-m.¢.~ @No@ weak m.¢ w.H @.w . ~.@ ~.- ~.e_ Emneflefim + P-m.¢.~ Ewnefiefim + P-m.¢.N m.» w.¢ m.w m.QH m.~H @.@ wpamuea weemefig w.@ w.¢ . w.~H >.mH w.m~ ~.mH mpeweee + @-m.¢.~ mpameew + @-m.¢.~ @.~ H.¢ >.N~ @.<~ @.e~ N.vH @-mHv.N P|m.<.N fimme Heme flwve meme Amme Lh@~e @Q=@=@e=H@z Hmee@=e emcee QQMHQUOZ emcoa mamnowez HCQEHQQHP m~@em 2e-m:m k . wfifiem meme Q ~a>\:<\muuumH xufleemme wcfixnnme fimwpficfi use eufim >@ ne>ee xmecme ewfiswmoz .w~@~ .m=H@H@ w=e~eo¢ mmxek one ce wefiwem wcficcmfim nme>|oN e no>e ~m~m~Hee wwmfiv moeflpm efipuee pzewvww um cefiwmpeme mfime |2ee e ce women me>@pm:~ee~m fienwcee epfisvwes xecec eowee~om EOHM hwv canyon we ween» Hm:c:< .m~ weewe 61 rates of return produced from the "next best" chemical alternative, dicamba, varied from 8.5 to 12.5 percent on deep soils and from 0.8 to 3.5 percent on the shallow soils.’ Chaining followed by maintenance treatment with aerially-applied 2,4,5-T (deep soils, dense canopy cover) produced annual rates of returns of 7.2 to 12.1 percent on the Rolling Plains (Table 15). Annual rates of returns from all other mechanical alternatives were less than 4 percent, except when root plowing was followed by establishment of kleingrass pastures. Since the annual rates of return were based on cattle prices of 44 cents per pound. adjustment factors as discussed for the High Plains are needed to compare alternatives on the Rolling Plains when beef prices are in the range, 34-to 54 cents per pound. The adjustment factors are: Alternative Adjustment factor 2,4,5-T 0.65 2,4,5-T + dicamba 0.60 Dicamba 0,56 '2,4,5-T +-picloram. 0,55 Tree doze 0,23 Root ploweseed (2,4,5—T as maintenance) 0.24 Tree doze-seed (2,4,5-T as naintenance) 0,23 Chain 0.51 Root ploweseed (grub as maintenance) _ 0.23 Tree doze-seed (grub as maintenance) 0.23 62 Scalp-root plow-seed 9 0.20 Root plow-roller chop-seed 0.22 Root plow-kleingrass 0.41 Treatment costs for chemical brush management alternatives evaluated on the Rolling Plains were the sane as for the High Plains (Table 5). Costs for mechanical treatments varied fran 8 dollars per acre (chaining) to 7O dollars per acre (scalp—root plow-seed) , depending on treatment intensity (Table 16) . No reduction in initial treatment cost was required to yield a 9 percent annual rate of reunm from herbicide applications for honey mesquite control on the Rolling Plains, except for aerial application of dicamba or 2,4,5-T + picloram to honey rresquite on the deep soils with relatively 10w production potential (Table 17). However, cost reductions were required for herbicide treatments to yield a 9 percent rate of return on shallow soils, except when 2,4,5—T was applied to dense honey mesquite stands. Except for chaining followed by aerial application of 2,4,5-T, cost reductions ranging from 6.56 to 41.28 dollars per acre were required for mechanical treatments to yield a 9 percent rate of return. The greatest cost reduction requirement was associated with the most intensive treatment, scalping-root plowing-seeding to a native range mixture, which was applicable only to the highest potential sites. In contrast, root plowing and establishment of kleingrass on the sane site required 6.56 dollars per acre reduction in initial cost to yield a 9 percent rate of reuxm. a; In general , the brush rrenagerlent alternatives increased the annual net cash flow when applied for honey mesquite managerrent on Rolling Plains rangeland (Table 18). Increased annual net cash flows from aerial 63 .moHuo@m QQHQGUN %O QHDHXHE o>H~mz U .@~@@\@~ m.o um wwfiflgmm >-m@nom m@@HQH@~@= 2 .mw:oEumo>:w xuowmo>H~ MCMUQQHD fi®U©m QUSMUCH HOG OU mumoo HCQEHGQHH ~m@~@=H Q m=H-@~m mxou -m: m=@xuH@ =@=m-@u »@H=oQ mofiwczou ~mu@mxa || 1| oo.mm oo.mm oo.mm Q¢.@m nsao mwm~wc@o~x»2o~m uoom || || .oo.om oo.om oo.om oo.om nsnw comm ‘| »mozu »u-o~|2owm poem 1| 1| 1| 1| oo.o~ || F|m.w.N womm 2oHm woon|m~mum oo.o¢ Qm.N¢ oo.ov oo.mv cc.cv om.Nm nnnu 0 u wo@m|m~ov monk oo.mw ¢m.>¢ .oo.om oo.mw oc.mw oo.mv pzgu Q @@@w-=oH@ poem -1 1| ¢@.- oo.N~ oc.w |» @-m.¢.~ cfimsu 1| || oc.mm oo.o< oo.om oo.Nm P-m.v.~ vo@w|@~ow wage || ‘I oo.mw oo.mv oc.mm oo.mw F-m.¢.~ Q @@@m-zo~@ poem -- Qm.~¢ oo.NN -- -- @@.¢~ @-m.¢.N 0% @N@@ @@~P Ammv Aflmv Amwv fi¢mV Ammv .fi@NV @U=@=@~=@wz ~@@@@=~ omcmc wumnmnoz omcoe opmwwwoz pcoepmona m-om 2o-m:m m~@om ammo Q ~n»\:<\monum~ xufiummmo w=@>-@Q ~m@u@c@ mam ouwm >@ ao>oo xmocmu ouwsvmmz w’ i. .w~@H .w¢@@~@ wmflfifloz wmxwk .mo@oomm wowmmwm mo on:~x@=_ o>@pmz u .w~om\n~ m.o an wofifimmm xflfimfinom wowfiuflnhoz n .mom:o@xo cofiwmsomo wcm mfimsficm wcfiwwoan womwonucfl .Hoa~:ou sways cfi woum@>:H Hmwfimmu wowum fiflm now owuwsu pmopupcfi §m m wossmmm o:~w> pcomoum um: ash m m:@-oum oxou :msm-mu,mcoxu~: -m: >@~=¢¢ woducsou ~mu~m>+. -- -- m@.@~ @>.H~ @m.¢ @m.m~ Qzpu mm@~m=@@H¥-=Q~@ pooz -- -- m<.>~ .wm.mm ~H.@~ m~.Hm nshw V Q@@@m , |mo:u ~m-o~|2nH@ poem 1| || -1 || w~.~¢ 1| e-m.¢.N uu@om|3o~m ~oo~|m~muw m~.m~ ~>.~m <~.¢~ ¢~.@~ ¢¢.- @~@¢~ @=~u Q@@@m-@N¢w monk ¢~.@~ ¢@.mm @~.@N m@.Q~ -.NN @m.@~ Qzhw u@@@w-:oH@ paoz -- -- fi¢.~ ¢ c -- @-m.¢.N =H@=@ -- -- mm.- >@.m~ ¢¢.wH m<.w~ @-m.<.~ u@@@m-@~Q@ Qwgk -- -- @¢.- @w.- >m.~m ¢@.~H P-m.v.~ u@@@m-:¢~@ paom -- ¢m.m~ Hm.m -- 1- ~¢.w @-m.<.N @~o@ QQQP @m.m m~.m @¢.¢ ¢ ¢ ¢ Emaofiofim + P-m.¢.~ Emhaflufig + @-m.¢.N @~.m ~¢.< @m.¢ o ¢ ¢ mnsmufia wpemufia mm.~ ¢¢.~ c ¢ ¢ ¢ ¢@e@uH@ + P-m.<.~ mpamufiw + h-m.¢.~ cj ~¢.~ Q Q ¢ ¢ @-m.<.N @-m.¢.~ fimmv fifimv fiwvv ~¢mv fimwv Ammv Qucwawucfimz ~@M»H=~ wmcon QHQHOQOZ mmcmo otwawuoz HCQEHQQHP mgom 30:95 mfiom QOQQ D §>\:<\wonu$ . - >u@ummmu wcwzanmo fimfipwcw was ouflw >@ no>oo xmocmo opfiswmwz 64 m.w>@~ .m@x@P we mcfimfig w=@H~o¢ @=~ =¢ ~m~@H~¢@ wwmfiv mmufinm @-~@u ~3o\wvw wcm mcofiumammo w~mu1zoo m co woman ~cmEuwm>:@ map co cnspon mo oump Hmzccm wm m wfiwfix ow mm>@~m=»ou~m mpfisvmoa xocos wo~om~om MOM @@~fi=¢@~ ~o~um\wv cowwosnoa wwou ~m@»@:~ .>~ oflnmk 65 ammo %O Mflfifiww 0£H UGM ©®UD~UGH HOG ®H®3 m®M%@£U Hm®H®HGH .moHuomm wowmmum we waspxfla o>@~mz Q .onum\n~ m.o pm wo@~@mm >-m@wom mowfiufinuoz .U®H®fiHwCOU HOG mm: m3o~m .:o~H~os w=@==@H@ am@>1oN oz“ mo wco map um ~o~nmoH~@@m mflv ~oa~coo swans wcm mzou mo o:Hm> omm>~ww on» w:~Q mwmou wcflumaomo ~m:::m wmmmoaucfi cam xuoww 1o>@~ mcfiwoonn wanna .~on~=ou swaps mo mpmou mmo~ ~usu\oo.¢wwv mo~mm cmmu wmwwm ~mpop m@ zoflw ammo pm: oak wafifigwpw Qxou -m: mcoxofia cmswfifimu xoficoa mofipczou ~mu@m>e 11 11 wm.m H~.v ~o.~ wo»v naps mmm»w:@o~x12o~m woom 11 11 o@.H @>.@ ~N.~ om.o @=~@ uwowm 1mo:u no-oa12o_m poem 11 11 11 11 mm.~ 11 P1m.w.N uumom12o~m poon1m~mom @>.¢ ~¢.¢- @~.¢ >@.¢ mm.H vm.o mono Q@@@w-@~¢@ monk ~w.¢ wm.o m@.H w@.~ ¢m.~ @@.~ @=~u U@@@m-zoH@ poem 11 11 -.¢ ¢m.~ m~.~ 11 @1m.¢.N =H@;u 11 11 1w@.o m<.¢ @m.¢ ~§.@ @-m.¢.~ uwoow1o~ow monk -1 -1 @w.¢ ¢~.~ @~._ @@.H @-m.<.~ U@@@m-3QH@ pooz 11 <~.¢- om.o 11 11 Nw.o @-m.¢.~ @No@ owne @m.@ m~.¢ ¢o.H @Q.~ ~¢.~ ¢N.~ a¢~¢H@M@ + @-m.¢.N ewgcfiufim + @-m.¢.~ <~.¢ mo.o 11 No.~ m~.~ ~w.Q mpsmufia mnemufia ~¢.¢ m~.o . mm.c m~.H ~<.~ mo.~ maamufiw + @-m.¢.~ mpsmufiw + +-m.¢.~ w¢.¢ m~.Q m@.¢ @H.H m<.~ @¢.~ P-m.¢.~ @-m.¢.N fimmv “Hwy -¢V Aomv ~mNv ;~@NV @u¢@=@~=H@z HmHw@=H omcoo oumnowoz mmcoa mwmnowoz pcmepmoae mfifiom :o-m:m mfifiom moon n ~nx\:<\m@»umV xufiummmo mcfiznnmu ~m@~@:@ wcm owfiw >2 ao>ou xmocmu mpmsvmoz @.w~@~ .m=@@_@ w=@-¢¢ mmxwk ocu co wofinom m=~==@~@ nmo>1oN m so>o Amnmflfiow w>m~V moofian ofluwmu u3o\v¢w wcm ww>Hwmcsou~m Honucoo oufisvmws xococ wowuofiww >2 wouswonm ~oaom\wv 3o~w ammo um: ~m:c:m;wowmo»u:~ mcofiwmaomo m~mu13ou co nmwmn .wH wan“? 66 aplications of 2,4,5-T ranged from 0.93 to l.43 dollars per acre on deep g soils, and from.0.l3 to 0.48 dollar per acre on shallow soils. In compari-d annual net cash flows were increased by 0.87 to 1.25 dollars per acre on l deep soils, and by 0.23 to 0.42 dollar per acre on shallow soils from aerial applications of dicamba for honey mesquite control. On the sites "with highest production potential, increases in.annual net cash flow exceeded l.40 dollars per acre from all herbicide alternatives except dicamba (l.25 dollars per acre). Of the mechanical alternatives evaluated on the Rolling Plains, root plowing followed by establishment of kleingrass pasture produced the greatest increasesir1annual net cash flow, from.3.38 to 7.01 dollars per acre, depending on site potential (Table 18). In contrast, root plowing and seeding to a native range mixture increased annual net cash flows by 1.09 to 1.95 dollars per acre on the deep soils. It must be emphasized, however, that these estimates do not consider potential economic interactions of the improved rangeland with associated uninproved nenagement_units within the ranching enterprise. Fran 5 to 9 years were required to recover the initial investment for aerial application of 2,4,5—T on deep soils, and 12 to 13 years were required on shallow soils (Table 19). These recovery times were the best' of the honey mesquite control alternatives evaluated. For example, from ll to 13 years were required to recover the initial invest- ment in dicamba applied to deep soils and from l7 to more than 20 years when shallow soils were treated. Since efficacy of the two herbicides were considered equal, this contrast indicates the economic sensitivity of rangeland enterprises to cost changes. 2_ 67 .moHoomm mwwmmnm mo waspxfla o>@~mz o .0HU®\D~ m.C HQ wofiflmmm x-m@nom mmvwownaoz Q .u:oEumo>:@ 0£H h®>OUOH ow @@~@=¢@~ on flfifiz mamox ow camp noummnw mopmuficcfi + om < :.xomn»>mm: we oeflw osu ~m cofipmnomo oz» ow mcaspoa mmonm ucowonmon wfisoz was .wo@nom ~=o->@@ map we uamm mm wmwzflucfl pom ohm ~o~nmu@~mmm mflv floapcou swans wan wzou mo mm:~m> wmm>Hmm .mo@~H::w~ommo ~:mEpmo>:@ o»m:Hm>o op now: xficoseou zwofiamm xumn|>mm: m mpcomonmoa nofiwom oefiw ask .uow:~u:@ mam momamsu pwmnopcfi on new woN@~Hp: wmz :o~@no: w=@==@~@ nmoxlom < m mc@~no~w oxou -m: mcoxufia :m:mH~mu xoflcoo mofipcsou ~@u@m>P -- -- @~ @~ QM mfi @=~@ ww@~m=M@_¥-zo~@ “cox 1| -| mfi + ow mfi om Qzgw unwmm ,@¢;@ nofifionuzonm poem || || -1 ,1 om 1| P|m.w.N uwoowuzoflm poon|m~mom + ow + ow ow ow ma wfi @=~@ Q@@@m-@N¢@ wane + om + ow wfl m~ ofi om nznw @@@@m-3¢~@ wooz || || - ofi m I- @-m.<.~ =H@;u -- -- + ¢~ + ¢~ cm QN % @-m.<.N @@@@m-@No@ QQQP -- -- + ow wfl QN wfi @-m.¢.~ Q@@@m-3o~@ ~¢o¢ || + ow NM || 1| ofi P-m.v.N mwow @@- o~ + ow wfl Nfi ofl . flfl Em~o~o@m + P-m.<.~ sm»o~uHm + P|m.¢.N >~ + om . MM Hfi ~H Nfi mnemufic mgemufia mfl + ow - m m m, wnewoflw + @-m.<.N mpemufiw + @-m.¢.~ N~ m~ Q w m Q P-m.<.~ @-m.<.~ hmmv Afimv -~@Q@@@@ w:@>nnmu ~m@~@:@ can opflm >2 no>ou xmocmu muwsvmmz @.w~@~ .m=@@~@ MCwamOK WQXQP 05H GO ~mnm-o© wN@a@ m®U@HQ QMHHQU H3U\¢Q% UGQ WCOMHQHOQO %~@U|3OU GO wwmms xuowmo>@~ CM QCQ wo>@pm:aouHm aOHPCOU OHMDUWQE X0505 ©ouoo~om Cw HC®EHw0>CH HMMHMCH H®>OU®% OH UOHMDUQH mH%W> .@~ ®~£®P I 68 Herbicidal treatment of dense canopy covers of honey mesquite on the highest potential sites on the Rolling Plains was estimated to increase weaned calf production from 14.6 to 22 pounds per acre annually over the 20-year planning horizon (Table 20). On shallow soils, the expected average increase was 3.2 pounds of beef per acre annually. Of the mechanical alternatives evaluated, highest expected anual beef production occured following root plowing and artificial seeding with a native range mixture (27.5 pounds per acre), or with kleingrass (61.0 pounds per acre). Grand Prairie and Cross Timbers The Grand Prairie coveniabout 7.0 million acres of which about 75 percent is undulating to hilly, deeply incised (locally stony) prairies. Thirty-eight percent of the region is native range (Table l). Elevation is 600 to l,O0O feet, annual average rainfall is 30 to 35 inches, and the anual frost-free period is 230 to 240 days. Upland soils are dark, deep to shallow and stony, calcareous clays with subsoils containing significant amounts of limestone. The bottcne lands are minor areas of reddish brown, loamy to clayey, calcareous alluvial soils (Godfrey, Carter and McKee undated). Vegetation of the uplands is tall bunchgrass, midgrasses, live oak (Quercus virginiana), and juiper (Juniperus spp.). stands of hardwoods, prinerily oaks (Quercus spp ), elms (Ulmus spp.) and The bottomlands support é . pecan (Carya illinoiensis). Mesquite infests about 55 percent of the"natim§§ é range, primarily as moderate to dense canopy cover on deep range sites (Tebleé Godfrey, Carter and McKee (undated) separate the Cross Timbers into the East Cross Timbers and West Cross Timbers, whereas Gould (1975) discusses the region as a single entity. For the purposes of this .wom:omwow cofipmswonm @w@~@>@ ocfisnopow ow wo~H~Hp: was wofinom wcficcmfim nwo>|o~ < .wo@uomm wopmmww mo onswxws m>@wmz u .waum\n~ m.o um wwfiflmmm xfiflmfinmm mow@u@nao: Q M wcflfiuopw oxou ?-m: wcwxofim :m:m-mu >Hm=oo wmfiwczou ~@QH@»@ -- -- @.H@ H.m¢ H.@m >.m< @=~u wm-w=H@H¥-3o~@ ~oo¢ -- -- ~.m~ ¢.- o.HN m.- @=~w . wwwm |mo:u noflfionlzowm uoom || -1 >.w~ -1 I- -1 e|m.w.~ uwwwmlzoflm uooalmfimum @.wH ~.wH H.@~ <.- ~.~H w.@H @=~w Q@@@m-@~o@ Qmhb @.@~ @.wH m.- <.¢~ @.- ~.mN @=~u @@@@m-:¢_@ yoom -- -- @.oN ~.w~ ~.mH -- P-m.<.~ =@m;u -- -- @.@~ @.@~ ~.m~ N.@~ @-m.<.~ U@@@w-@N¢@ Qwhh -- -- ¢.@~ N.<~ ~.>H ~.¢~ P-m.¢.~ U@@@w-:oH@ pacz -- m.- -- -- m.<~ m.wH @-m.<.~ @NQ@ make w.¢H ¢.mH @.- ¢.Q~ @.mH ~.@~ Ewgofiufim + @-m.¢.~ em~¢~@H@ + @-m.¢.~ @..~H fip=@s~@@~»@~@v @=¢z fimmv fifimv ~mNv Acmv hwqv ~@~V @Q=w=@~=H@z fimfip omcoa QMMHQUOZ omcoa QQQHQQOZ wcweuaone mfifiom zofifimsw wflfiom move n . ~n»\:<\w@womV xpfiommmu wcfixnnmu Hmfiuwcm cam wuwm >2 Hm>ou »@o=@@ wpfisvmoz co wwwmn mo>@~w:~op~m mpfisvmwe xmcos wmuuofiww EOHM m~nmmx\mnum\n~V cofiuuswonm m~mu wvcmmz fimwok .w~m~ .m:@w~m mcfiflflom wmxoh map co wcoflumnmmo mHmu|3ou .¢~ wfipmw 7O research, it did not appear necessary to neke a division and total area was estimated at roughly 3 ndllion acres (Table l). Average anual rainfall is 28 to 35 inches, increasing eastward across the resource area. Topography is udulating to gently rolling with uplands supporting oak trees and tall buchgrasses, and the bottomlands supporting hardwood stands dominated by oaks. Upland soils are light, slightly acid, loanw sands, and sandy loams. Bottomlands are ndnor areas of brown, slightly acid, loamy, alluvial soils. Hbney mesquite is a lesser problem in this area than are oaks. Moreover, aside from the East Texas Timberland, the Cross Timbers supports the least honey mesquite problem, based on acreage infested, of the Texas land resource areas (Table 1). About 95 percent of the ranch firne operate with cow herds of fewer than 200 head (Table 3). Based on average acreages from 1973 to 1977, about 59,400 acres were treated annually with herbicides for brush control, and mechanical methods were applied to about 63,225 acres (Hoffman l978). Thus, about 3 percent of the rangeland on the Grand Prairie and Cross Timbers receives brush control treatment annually. Highest annual rates of return from honey mesquite control in the Grand Prairie zuuiCross Timbers land resouce areas resulted from aerial applications of 2,4,5-T, regardless of site potential or canopy cover of mesquite (Table 21). In general, 2,4,5-T was followed by 2,4,5—T +-dicamba and then 2,4,5—T +-picloran1wmen.ranked relative to magnitude of anual \ rates of return. The lowest anual rates of return from.herbicide alternatives resulted from aerial applications of dicamba or basal appli- cations of 2,4,5-T. 71 .mo~oomm mmpmmnm mo osspxfie o>@pmz u .m>mamm fiwmwn mcfiumuwwcfl Amy P|m.w.N waw onum\nH m.o am Empofiofim 1 H|m.v.N pmouxm oauw\n~ ~o.o um wm@~mmm »11@1~@@ mmufiufinnoz n .>_1@=¢@ wcasuoa ucm mumoo uuowmw -@2 cofipmfimcw woesmmw mmmoonm mwce .mo~mn ~mon map ow owmn :o@~m~m:H mossmmm cm w=1@@@ An owns we Ame cnsuon mo wmpma fimcfisoc HO uwxams we o~wE@~mm.:< .:n:pon mo mmpmn Hams woaowfiwcou ohm wcm wwummefi cofip 1m~m:@ owsfiocfl pom on cnsumw mo wopmn ~m:=:m .w::h .m~m-ow wnmfi ucmpmcou cfi wwwumhonm QHQZ mcasuop wcm pmou .xuoumm>@~ w=1@@@~@ wcm fioaucoo cmswn cw Hmpfimmu p:oE~mo>=H new mcfipmnomo Hfim wnowflwcou cwspww we owmn ask m omfis omfis spasm mswwom COHCQQ Q9723 ucmnnmk .232 mofipcsoo HMUHQXF @.N 1| 1| 11 ~.¢ 11 _ 1| 11 name mmmaw:H@~x1oxmn12oHm uoom 11 o.~ 11 11 11 1| ~.N 1| mass mwmnm:@o~x12o~Q poem 11 11 1| o~.1 1| o.~ 11 11 nsnw owoom|oxma|2o~m woom 1- 1- -1 11 -1 -1 m.< 1- Qzhu @@@@m1@¢=U 1@H~Q~|3o1@ ~¢o¢ ~11 m.w ¢.m1 11 m.¢ 11 -1 1- @=~@ Q@@@m1=o1@ pagm 11 w.o 1 .11 11. 11 11 11 . nuns wmmaw:Hw~x1oNow monk 1.m . >.m 1.»- 1- ~.¢ ¢.H “.1 @.~ @=~¢ Q@@@m-@No@ QQHF 1- 1- 1- @.¢ -1 -1 w.1 1- @=~@ @N@@ @0111 w.1 1.1 -1 w.m “.1 1- 1- @.~ . 11¢ 1 11¢ -1 1- @.m Q.1 ¢.@ 1.1 1- m.@ E¢~¢1Q1@ 1 @-m.¢1~ EQMQHUHQ 1 @1m.11~ ~.w ~.@ “.11 _m.H m.@ ¢.m -1 w.m mnemufig mgawvflc m.~H @.@ ~.N “.1 H.¢~ ~.@ 1- ~.@ @@E@Q1@ 1 P-m.¢.~ @@E¢U1@ 1 @1m.11N 11 11 -1 1- 1| @.m 11 w.m fimv @-m.<.~ Amy @-m.¢.~ m.~1 @.Q1 m.m w.m m.H1 m.@H 1- w.¢1 @-m.<.~ @-m.v.N ~@~v ~¢Nv ANNV ~mN~ Awmv ANNV AQNV fiflwv @U=@=@p=1@z 1@1~1=H wmcwc owmamwoz mmcoc wwwnowoz omcoc owmnucoz. ucoepmonk 51 2 mfiwom moon m-om zo-w:m w~mow mwmc mam Ea wwon1 ofinfima cma. s .& u . . Q ~nmm>\:<\monumv xufiummmu m=1>»~@@ ~mH~H:M wcw owflm >@ ao>oo xmocmu mwfisvmoz 11 .w~@1 .mmxoP m mo waonefik wmonu can ofinflmnm wcmnw 0:» co wo@aom m=@==@H@ amo>1oN m no>o ~mnmH~ou wnmfiv moolmm ofiwpmu w3u\vvw U-Zu. WZD4JMHDLD JHBJIZD) 3D 3DOU‘OJID:-JW)>Z4 43.41.15) >A4$V7)..1 x1111): .:>i| x11 1||1>|>| || I | | . |1 1 72 All mechanical methods produced internal rates of return of less than 5 percent on deep soils on the Grand Prairie (Table 21). On shallow soils, negative annual rates of return resulted frdm all mechanical alter- natives except tree dozing followed by grubbing which yielded only 0.9 percent (essentially a negative result if the potential impact of inflae tion is considered). Comparatively, the mechanical practices were more effective, based on annual rates of return, when applied to deep soils of the Cross Timbers. For exmnple, root plowing and establishnent of kleingrass pasture were estimated to produce a 2.7 percent annual rate of return on the Grand Prairie compared1x>a.7 percent retun for the same practice in.the Cross Timbers. Adjugumgqg factors to compare annual rates of return when cattle prices range from 34 to 54 cents per pound, as discussed for the High Plains, are as follows: Adjustment factor Alternative Grand Prairie Cross Timbers 2,4,5-T 9,53 0.7l 2,4,5-T (B) 0.39 -- -2,4,5-T-+ dicamba 0.60 0.69 Dicamba 0.55 0.63 2,4,5-T +-picloram 0.55 l -- Oil 0.47 0.45 Tree doze 0.29 -- Tree doze—seed natives 0.24 0.31 Tree doze-kleingrass -— 0.54 Root plow-seed natives 0.26 0.37 Root plow~roller chop—seed 0.30 -- natives 73 Root plow—rake-seed natives 0.23 -- Root plow—kleingrass 0.30 0.55 Root plow-rake-kleingrass 0'38 0'33 Since higher herbicide rates are generally required for honey mesquite control on the Grand Prairie zumiCross Timbers, treatment costs were higher than for the Rolling Plains, Rolling Red Plains or High Plains land resource areas (Table 22). In addition, basal treatment with 2,4,5—T was given as one of the nore popular practices for two site/honey mesquite _ canopy cover situations. Costs of basal treatment, because of labor and herbicide requirements, were 3 to 4 times the cost for broadcast 2,4,5-T applications to the sane sites. No cost reductions wererequired for aerial applications of 2,4,5-T or 2,4,5-T + dicamba on deep soils to yield a 9 percent annual rate of return in the Grand Prairie cn~Cross Timbers (Table 23). Cost reductions of 3.37 to 3.43 dollars per acre were required for aerial applications oi dicamba to yield a 9 percent rate of return, and equivalent performance of 2,4,5—T + picloram would require cost reductions of 1.97 to 3.17 dollars per acre on deep sites of the Grand Prairie. All brush management alternatives were estimated to require _cost reductions to yield a 9 percent annual rate of return on shallow sites of the Grand Prairie (Takfl£e23). Cost reductions for 2,4,5-T »ranged from 3.04 to 4.17 dollars per acre whereas reductions of 4.30 to 5.43 dollars per acre were required for dicamba to yield a 9 percent annual rate of return. All mechanical practices required a reduction in their initial cost, regardless of site potential/honey mesquite cover situation, to yield a 9 percent aual rate of return. The cost reductions to yield a 9 percent 74 .mw@ummm voummww mo oa:wx@=_ o>@~mz. .m~onE@h wmonu U .mxmnmm ~mmmn w=@»@@@@=H Amv @-mm~fi xoowmo>fi mcfiuwmun wowwm QUSHUGM #02 0U wumou HGOEHQQRH Tfiufifl m ow“: ow“: spasm msvwom coucwm noxnwm pcmnnmk wfififiz mmfiwcsoo fimufimxk oo.¢H~ || -1 1| oo.~m || || 1| nape mmmnmc@o~x|oxmu|3o~m uoom || oo.mw || || || -1 oo.em || nsnw mmmnw:@o~x|2o~m uoom |» 1| 1| oo.ow || oo.m> 1| || capo woow»oxmu|3o~m uoom -- -- -- -- -- -- Q¢.~< -- @=~u Q@@@m-@w=U »@H~¢~-zo~@ ~oo¢ ¢¢.@< ¢¢.- ¢¢.om -- @o.@< -- -- -- nspw uw@@m-z¢H@ pocz -- ¢Q.~< -- -- -- -- -- -- pahu wm@~w=@@Hx-@N¢w.@-P ¢¢.m@ ¢¢.@m -- o¢.m< ¢@.m@ @¢.o< o@.@@ ¢Q.mm nshw Q@@@m-@~o@ QQFP || 1| oo.mm -1 || || oo.mm || nsao mwow monk Qo.Q~ ¢@.m~ @¢.m~ Hm: om.~N An» -- . ¢¢.mH fifio Hfio --, -- m>.@ m~.@ m~.@ mB.@ -- m>.@ E-oHu@@ + h-m.¢¢~ E@~¢~QM@ + P-m.q.~ mw.w mw.w mw.w mw.w mw.w mw.w -- mw.w mnswofim wnswufim m~.@ m~.@ m~.@ m~.@ m>.@ m~.@ -- m~.@ mpewufiw + h-m.<.~ wnamofiw + P-m.¢.~ -- -- -- -- -- ¢¢.m~ -- QQ.¢~ any P-m.¢.~ fimv P-m.¢.~ @H.@ @~.@ @~.@ @H.@ @H.@ @~.@ -- @~.@ P-L.¢.~ % e-m.¢.N h@- fi¢~v ANNV Am- hwwv ANNV HQNV AMNM @Q=~=@p=M@z ~m@pHc~ QMCQD QHMHQGOZ QMCQQ QPGHUQOZ omcoc QMQMQUOZ QCQEHNQHP mflfiow noun mflfiom 2o-m:m mflfiom mama Q mfipflmpm ,wcmnu ~umo>\:<\wm»umv xwfiummmu wzfixupmo flmfiuficw can oufim >@ »o>ou xmocwu mufiscwoz .w>mH .mmxwh mo wnwnefih wwouu wcm mfiwfimum wcmpu map co mo>@wm:wop~m fionpcou opfiswwme »@=¢; wowumfiwm now ~onum\wv mwmou ~m@wH:~ .N~ o~nmP 75 .mm@oomm nopmmwm mo opspxfie @>@~mz u .m>mpmw ~wmmn mcflwmuwwcfi Amy a1m.w.N can maum\n~ m.¢ pm Ew~o~uHm + e1m.v.N wmmuxo oaum\n~ ~o.oum @@>@~@m >-w@n@m mowfiufinmoz n .mow:@mxo cofipmaomo cam m~Em@:m mcfinwonn wwmmwaucfi .~onp=ou :m:~n ca nopmo>:@ flmpfimwu nmuwm -m pom omumcu pmonmwcfi wm m moesmwm @:~m> ucowmam was one m mmfiz omfiz zumnm mswmom copcma noxamm pcmpamw mfiflfiz wowpczou fimufimxa mo.~w 11 11 11 Nm.m¢ 11 11 11 nsuu mmmum=Mo~x1oxm»12oHm Hoax 11 mm.v~ 11 11 11 11 mm.o@ 11 nnau mwmnm=@o~x1zo~m Hoom 11 11 11 @~.Nm 11 oo.om 11 11 nsuu uuoom1oxmn13o~m uoom 11 11 11 11 11 11 @~.- 11 @=~u Q@@@m1@¢=u »@-o~1zo~@ Hoom ¢m.- w~.~ @m.@< 11 _~.¢N 11 11 11 @=»@ Qw@@m1:¢~@ Hoom 11 m@.w.@< ¢~.w~ ~@.- ~m.¢m nsnu unoow1o~ow wane 11 11 11 ¢¢.¢~ 11 11 m~.~N 11 nspu oNow @@~@ ¢@.¢~ om.m 11 @~1w wN.- 11 11 1¢w._ 1 _@¢ ~@o 11 11 mw.m @m.@ o >@.~ 11 -.m smno~u@m + @1m.¢.~ smnoflufim + @1m.¢.~ @¢.~ ~@.m mm.m @~.@ ~¢.m m<.m 11 ~w.m mnsmufio mnemufla o. o m<.m ¢m.¢ o o 11 o mpsmofiw + @1m.¢.~ mpemufiw + @1m.¢.N 11 11 11 11 11 ~H.m~ 11 @@.@ Amy ~1m.<.~ Am. @1m.¢.~ o o >~.¢ <¢.m o Q 11 o @1m.<.~ P1m.¢.~ ~@~v hwmv hwwv fimwv hwwv ANNV AQNV W-~ @Q=@=@~=@@: ~@@~@=_ omcoa owmnowoz omcoa oumaowoz mmcma opmgmuoz QCQEHMQHP mfiflom mama mfiwom zo-m:m mfiwom moms Q maonewe mmouu mwpflmam wcmnu ~nm@x\:<\wunumV xafiummmu mcwxnamu ~m~uw:@ new owfim >5 no>ou xmocmu owfiswmwz @.w~@~ .mh0£EwP mmosu wan ofinflmam mamas oz» co wofinmm w=fi==@~@ ~@@>1Q~ m no>o ~mnmH~ow wwmflv mmufiam o~p~mu p2u\vvw pm mcoflpmnomo m~mu12oo so wwmmn xoopwo>H~ mcwwoonn wmwwm ncm mo>@~m:no-m fionwcoo opwsvmoa >020; nmuumfimw 2“ ~:oEpmo>:@ osw co cnzwon we mums ~w:::m wm m mcfiwfiofix new @@~@=¢@~ A@aum\w~ cofiuuswon wmoo ~@Hu@:H .mN m~nme 76 annual return were estimated to range l.78 dollars per acre for root plowing and seeding a native range mixture in the Cross Timbers to 8l.05 dollars per acre for root plowing, raking, and seeding kleingrass. Increased annual net cash flow ranged from 0.28 to 1.70 dollars per acre from aerial applications of 2,4,5—T on the Grand Prairie or Cross Timbers, compared to -0.l6 to l.34 dollars per acre where dicamba was applied (Table 24). Increased annual net cash flow from aerial appli- cation of 2,4,5—T to deep soils of the Grand Prairie varied from 1.09 to 1.38 dollars per acre, and was 0.28 to 0.62 dollar per acre on shallow k sites. Across all site and canopy cover situations on the Grand Prairie, average increased annual net cash flow from aerial applications of 2,4,5-T was 89 cents per acre. When dicamba was substituted for half of the 2,4,5—T, average annual net cash flow was reduced to 79 cents per acre, and was reduced to 85 cents per acre when picloram was combined with 2,4,5-T. Average annual net cash flow from aerial applications of dicamba was estimated to be 46 cents per acre, 48 percent less than when 2,4,5—T was applied alone. On deep soils of the Cross Timbers, average annual net cash flow from 2,4,5—T was l.48 dollars per acre, l.39 dollars per acre from 2,4,5-T + dicamba, and 1.08 dollars per acre from dicamba. Greatest increases in annual net cash flow from mechanical methods on the Cross Timbers, 5.78 dollars per acre, occurred where the honey mesquite was root plowed and deep soils were seeded to kleingrass (Table 24). Root plowing, raking the debris, and seeding kleingrass on the Grand Prairie increased the annual net cash flow by 4.29 dollars per acre. The same mechanical treatment but artificially seeding with a native range nxixtmire increased annual net cash flow by 53 cents per acre on deep soils but decreased cash flow by 2 cents per acre annually on shallow soils . 77 mcflumofincfl any @1m.¢.~ mam onum\n~ m.o pm Emwoflufim + P1m.w.~ umouxo oPuw\n~ >@.o um wmxmnmw >-m@nom wowfiuflnnoz .wo~ow~m:oo HOC mm: m30a% ammo MO MCHEMH ®£H U56 U®@5~UCw uo:“E!>mumnmcu umonou:~ .wo@oo@m woummwm mo mwspxfia o>@~mz o .m>mnmm.~mmmn Q .CONHHO£ Mflmflfiflafi Hm®% ON QSH mo ucm osp pm ~m~nmoH~mmm wfiv fioawcou swans mam mzou mo o:~m> omm>~mm on» w:_@ mpmou,w:@pmaomo fimsccm nommonocfi ucm xuoumo>@~ mcfiwoman wownm .~o~p=ou swans we wwwou mmo~ ~p2o\¢¢»v wo~mm ammo wmnwm ~mpop mfi zofim ammo pa: oak m omflz ow“: nwmam mscmom copcmo nmxnmm pcmppme m-@2 moflpcsou fimufimxa ~o.m 11 11 11 mN.¢ 11 11 11 DDHU mmmnw:@o~x1oxm~12o~m woom 11 w>.m 11 11 11 11 om.~ 11 nzno mmm»wc@wHx12o~m poem 11 11 11 No. 1 11 mm.o 11 11 nsuu uwowm1oxmu12o~m woom 11 11 11 11 -1 11 <~.~ 11 naps @@@@m1@¢=u ~@-¢~1zo_@ Qccm w<.~ @<.~ mw.o1 11 @~.~ 11 11 11 nsao uno@m12o~m ~o¢¢ 11 -.m 11 11 -1 -1 1- 11 @=~u mm@»m¢@@~¥1@~¢@ mmye >o.N oo.~ m~.H1 11 <¢.¢ mm.o -.m m<.~ nspu Q@@@m1@~Q@ woke 11 11 11 om.o 11 11 co.o 11 Qsgu @~@@ Qowk m~.~ ~>.~ ~@.¢ wm._ 11 11 @<.~ Mao MHQ 1- -1 ~¢.¢ @m.¢ ~m.~ m¢.~ 11 mw.@ E@~o~QH@ + @1m.¢.~ Emuo~u@m + ~-m.<»~ ¢m.~ @~.¢ @~.o1 -.o om.o H~.o 11 w@.¢ ansmuwc mnsmufla ~@.~ m~.~ m~.o ~m.Q w~.~ Ho.~ 11 >a.o mnemufln + H1m.<.N mpemufin + +-m.<.~ -1 11 11 .1- -1 ~@.Q -1 m~.~ Amy »-m.¢.~ Amy @-m.¢.~ o>.~ @~.~ w~.o No.0 wm.H mo.~ 11 @o.~ @1m.¢.~ ~1m.¢.~ fi@~v h¢~v -- fim- AQNV ANNV BQNV fifimv @u=@=@~=@@= Hm-@=_ . wmcma owwaowoz omcoc owmsowoz mmcoc oumnowoz wcvsumowe m~@om move m~@ow zofiflmsm mfifiom mooa muonefih mmopu o@~@m~m ncmau ~amo>\:<\wmnumV xwwumnmu mcfixnumu fimfiuficw new ouww >3 ~@>ou xmocmu ouflsvmoz .w>mH .mH®QEMP wmohu can N ufiafimam wcmau on» co nofinom w¢H==@~@ nmm>1oN m no>o Amnmfiflow wwmflv moofinm oflpuwu u2u\vvw pm mcofiumnomo w~mu12ou CO momma mo>Hum:nmw~m OHMDUWQE XQCOS UQHUQMQW EOH% UOUDUOHQ a0HUd\%g ZOAW ammo H®C>afl3CC@ UQWNOHUCM av .vN ofinmh \v 78 From 9 to 19 years were required, depending on site potential, to recover the investment in aerial application of 2,4,5-T for honey mesquite control on the Grand Prairie, and Cross Timbers (Table 25)- In ¢0mPaTi$0n» from.l4 to more than 20 years were required to recover the initial invest- ment in dicamba, the only aerially-applied herbicide which did not contain _ 2,4,5—T. Time to recover the initial investmnt in.mechanical methods fori inprovement of rangeland infested with honey mesquite ranged from l5 to nnre than 20 years on the Grand Prairies,and.from.lO to more than 20 years in the Cross Timbers. In general, there were relatively small production response differences within site/canopy cover situations to aerial applications of various herbicides on the Grand.Prairie or Cross Timbers (Table 26). For example, on deep soils supporting moderate canopy covers of honey mesquite on the Grand Prairie} annual beef production ranged from 22.4 to 24.2 pounds per acre following herbicide treatment. However, production differences following treatment compared to pretreatment weaned calf production varied widely among sites. For example, following aerial application of 2,4,5-T, weaned calf production on deep soils was increased by 6 pounds per acre aually after moderate canopy covers were treated, and increased 7.1 to 9.9 pounds per acre-after dense canopy covers were sprayed. 'Aerial spraying of honey mesquite on shallow soils increased annual weaned calf production, on the average, by 5.7 pounds per acre on the Grand Prairie. Production responses to mechanical treatments for improvement of honey mesquite-infested rangeland varied widely on the Grand Prairie and Cross Timbers. Root plowing and seeding shallow soils supporting moderate mesquite canopies on the Grandlkairie produced 22.2 pounds per acre of beef annually, essentially equivalent to results from.aerial spraying. However, establish- .moHommw wowmmvm mo oaspxfie o>fi¢mz“v .m>@nmm fimmmn mcfiumufiwcfl Amy P1m.v.~ cam oaum\n~ m.ouw Ew~o~QHQ + e1m.w.~ pmouxo o~um\n~ >@.o um @@@~@@@ xfifimflpmm mmwfiofinnoz .~:@E~m@>:@ ms» Ho>oooa op @@~@=¢@~ on -M2 mamox ow swap aoumoam mowmufiwcfi + ow < :.xumn1>mm: mo msfip map pm cofipmammo on» op mcaspon mmonm ucommnmoa cflsoz pan .uofi~om p:o1>mm ocw mo ~amm.mm wou:~u:@ ~02 mpm ~@H@¢Q@~@@@ mfiv ~oa~=ou swans ucm mzou mo mm:~m> owm>~mm .mm@pH=:p~ommo p:wE~mo>c@ @pm:~@>o op mom: xficoeeou zwofinom xu@n1>mm: m mucomonmon uowaom mew» och .wow:~u=@ mam momawcu umoaoucfi oc can wo~H~wu: mm; cowfinoc w=@==@~@ nm@>1o~ < w owfiz mm“: sumam osvmom cowcoa aoxamm pcmanmh w-H2 mowwcsou ~wu@m>& + om 11 11 11 o~ 11 11 11 nsnu mmm~w=@o~x1ox@n12o~m ~oom 11 mfi 11 11 11 11 mfl 11 . nape mmm~wc@@~x12o~m woom 11 11 11 + om 11 + om 11 11 nape owoom1oxmn1:o~m uooz 11 11 11 11 11 11 - 11 ammo onoom1mc:u no-oa13o~m poom wfl ofi + om 11 mfl 11 11 11 nnnu owoom12o~m woom 11 mfl 11 11 11 11 11 11 nsuo mm@~w=H@~x-@NQ@ woke mfi mfi + ow -1 1 QN 1 mfl mfi. 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North Central Prairies The North Central Prairies, undulating prairies and nearly level valleys, cover about 6.5 million acres in.the extreme north and central part of Texas (Figure l). More than 3.5 million acresznnaused as native range (Table l). Elevation is 900 :5 1,400 feet, annual rainfall averages 20 to 30 inches, and the anual frost-free period is 225 to 240 days. Upland soils support scrub oak, honey mesquite, and a mixture of Hfidr and tall—grasses. The upland soils are brown, sandy loam to silt loam.and slightly acid over gray, neutral to alkaline, clayey subsoils (Godfrey, Carter and McKee undated). The bottolands, ndnor areas of brown to dark gray, loamy and clayey, neutral to calcareous alluvial soils, support hardwoods and honey mequite. About l.6 million acres of the native range, roughly 46 percent, support honey mesquite infestations. About 79 percent of this infestation occurs on range ' sites of higher production potential. Most of the ranches, 96 percent, in the North Central Prairies and the closely associated Cross Timbers vegetation areas operate with fewer than 200 cows (Table13). Only about l percent operate with 500 or more beef cows. These vegetation regions support 6.3 percent of the State's ranches andiabout 5 percent of the beef cow inventory. Based on results of this study, the North Central Prairies vegetation region was one of the most profitable for honey mesquite control. Annual rates of return from aerial applications of 2,4,5-T ranged from 82 11.8 to 24.9 percent on deep soils, and from 8.2 to 23.4 percent on shallow soils (Table 27 ). Averaged across all soil / canopy cover situations for the North Central Prairies, rates of return were 16.4 percent from aerial applications of 2,4,5-T, 14.5 percent from 2,4,5-T + dicamba, 11.2 percent from 2,4,5-T + picloranl, and 10.2 percent from applications of dicamba. The differential response among range sites related to soils was not as great for the North Central Prairies. as for other land resource areas . Mechanical practices, except chaining and seeding to a mixtmte of native grasses, produced less than 7 percent annual rates of return with several of the practices resulting in negative rates of return on shallow soils of the North Central Prairies (Table 27). Differential in site potential, deep versus shallow soils, was much more pronounced in the economic response to mechanical methods than to chendcal alternatives. As with other land resource areas, root plowing and establishment of klein- grass pastures resulted in higher rates of return than from other mechanical practices. Establishment of bermudagrass pastures resulted in annual rates of return, 6.5 percent, approximately the same as for establishment of kleingrass. pastures. If alternative rates of return are required for cattle prices ranging from 34 to 54 cents per pound, as discussed for the High Plains region, t-he following adjustment factors for the North Central Prairies may be utilized: Alternative Adjustment factor 2.4.54? 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Q7 =- 84 .wo@uomm woummwm mo oa:px@E o>@pwz u .>mnmw Mmmmn moumufiwcfi zufisz hwy P|m.v.N can wnum\n~ m.o pm wwfifimma mm: sofizz Emaofiufim can P|m.¢.N wmouxo onum\n~ No.0 pm wofiflmmm zfifimfinom womflufinaoz n .>-@=¢@ mcasuon vcw wumou puommm flfifiz :o@~m~w:H mmesmmm mmouonm wash .moHmn flaw» mag op mpmp coflumfimcfi uoesmwm cm mcfiwwm >2 mums on xme cnspmp mo wmwmn Hmcfieoc ao.~oxamE mo mpmsfiwmw :< .ca:»@~ mo magma Hwoa wuawwfiwcou mam ncm wpommefi =o@um~m=@ @w:~u:@ Po: ow cpswon mo mouma fiwsccm .m::P .mpm-ow w>m~ pcmpwcou cfi wouuomopm mam: wcnspma @=m.mpmou .xuowmo>HH mcflvoonn wcm fionwcou cmsnn cw fimpwmmu PGOEHm®>GH wcm wcwpmnmmo flfim mnoufiwcou cnsuwp mo muwp use m n@:on< mmmm mcocmowm npmam czopm xumw omw@m uswmwcoz osucweou moflwcsou Hmufimxk -- -- -- -- -- -- N.~ Q.» -- P-m.¢.N ww@@m-@¥@»-=oH@ “com o.~| -1 ~.~| || 1| w.N ll || 1| nsuo unoom|oxm»|2o~m uoom || -1 || || || m.o || m.¢ || nsnu wmm~wmw:E~wm|mxmn|2o~m poem -- -- -- -- -- -- -- m.@ -- nspu mm@~w=@@~x-@¥@»-:o_@ Qooz HNQV HQNV Ammv ficmv Away ~m.@mv fi-v ficmv »Am- @@=@=@~=@@z H~@»@=~ owcua mpwnvwoz umcon opmnomoz nucoepmuwe mfifiom 3o-@=w mflfiom QQQQ ->\:<\moau@ ~o>ou xmocmu opfinvmoz .@@==@~=ou .- mfinmk 85 Oil (2,4,5—T as maintenance) 0.62 Oil (oil as maintenance) 0.48 Tree doze-seed natives 0.45 Tree doze-rake-seed natives 0.31 Tree doze-rake 0.37 Tree doze ' ' 0.32 - Tree doze-rake-kleingrass 0.23 Root plowerake-kleingrass 0.20 Root plow-rake-Berrrudagrass 0.25 Root plow~rake—seed natives (grub as maintenance) 0-31 Root plowerake-seed natives (2,4,5-T as maintenance) 0.36 Costsiifiaerial herbicide treatments on the North Central Prairies\were the same as for the Grand Prairies and Cross Timbers (Table 22). Cost of mechanical practices varied from 10.00 dollars per acre (chaining) to 70-00 dollars per acre (tree doze-rake-seed native grasses) on the North Central Prairie (Table 28). In only one case, the site with the lowest potential productivity, was a cost reduction required for aerial application of 2,4,5—T or 2,4,5-T + dicamba to yield a 9 percent annual rate of return (Table 29). However, except when applied to sites of highest potential production (initial carrying capacities of 20 acres per animal unit per year or higher),cost reductions were required before aerial applications of dicambaiyielded a 9 percent annual rate of return. For example, a cost reduction of BT31 dollars per acre would be required for 0.67 pound per acre of dicamba aerially applied to sites with pretreatment carrying capacity of 23 acres per animal unit per year to yield a 9 percent rate of return“ Cost reductions were required of all mechanical practices, 86 Amv P|m.w.N wcm w~um\n~ m.o pa woflfimmm mm: sufi 5| .w~:oEpmo>:M xuopmo>@~ w:@n@@nn.ooncm on:Hu=@ Ho: on m .wo@ummm woummwm mo onspxfis o>Hpmz U .>mamm fimmmn moumuwwcfi sufisz :2 Ewaofioflm + b|m.v.N pmouxo m@um\nH no.0 pm @@@~;@@ >-m@n@m wmw@u@n»o: Q HWOU HCQEPMQHH ~®wH@C~ M ~m:o~< mmmw mcosmmpm zpwnm V czoam xumw ommwm oswmwcoz msucmsou mwfiwanau ~@uM@>@ || || || || || || oo.ooH oo.~@ || e|m.<.~ Qw@@m|@¥@H|:o~@ uooz oo.o~ || oc.m@ || || oo.mo || || || nzwu uw@mm|@xm~|2o~m woom || || || || || oo.ow || oo.ow || nspu mwm»wmn:E~wm|o¥m~|zoHm poem || 1| || || 1| || || oQ.ow || nfinu - wmmHw:wm~x|oxmn|3o~Q woo: || || || || oo.o@ || || O0.0m || nsuu mmm~mc@o~¥|wxm»|o~ow oouh || || || || || || || || oo.mm nswu o~ow mo»? -| Qo.Hm -| @Q.@¢ -| |- |- || -| Amy P|m.¢.~ @x--@~¢@ @@~@ oo.cm || oo.mw || || co.m¢ || oo.w¢ || @=~u u@@@m-@x@~-@~o@ Qvpk || . || || ¢@.@m || || oo.o~ || .|| capo uw@om|o~on wok? || || oo.o~ || || || || oo.o~ || fifio ~@o || || || || || || ¢¢ cm || |- Amy P|m.¢.~ MMO || || || || || oo.om || oo.om || P|m.¢.~ u@@@m-@@;u ~@H~o~|@¥@»|=@¢;u || || || || || || oo.~N || || e|m.¢.~ @@@m|=@@;u -| || || ¢¢.QH || -| || || || ~-m.<.~ Q =@@;u || co.om || o¢.o~ || || || || oo.o~ Amy @|m.q.~ fimv P|m.¢.~ ANQV A¢~v Ammv AQNV fiwfiv ~m.@mv -~v A¢mv Amwv @U=@=@~=M@z ~wH~@:~ wmcmn opmkunoz omswa mpmpowoz ~=os»m@~e mflflom zofifimsm mH@om mvoa Q ~ax\:<\monumv xpwuwmmu wcfixaamu ~m@u@=@ mam ouwm >2 no>ou xmocmu opwscmoz m.m~a~ .mwx@e .nmH»@m~¢ fimaucwu swnoz osw now wopm:~@>o mo>@~m:»opHm floapcou opwzcmoe xococ wowuoflmm mo ~onum\wv mpwou ~nHu@:H .w~ @_@@P 87 11 11 11 11 wv.mv 11 11 mo.>~ 11 nsuu mmmnwc@o~x1oxmh1u~ow om»; 1- -1 -1 -1 1- -- 1- 1- oN.- QQQQ o~ow weak 1- ~o.@ -1 Qm.Q~ -1 -1 -1 1- -1 AQQ @-m.Q.~ @QQ~-@~QQ QQQQ vo.wm 11 QQ.mQ 11 11 o~.~N 11 -.wN 11 Qsgu onwom1oxm»1o~ow ooph -1 1- -1 Nm.- 1- 1- ¢N.vw 1- -1 QQQQ QQQQm1@~QQ QQQQ -1 -1 m>.w~ 11 -1 -1 -1 QQ.Q -- ~Ho .~@n -1 -1 -1 1- 1- -- Q_.Q 1- -1 AQQ Q1m.Q.~ QQQ 1- 1- 1- -1 1- @m.- -1 ~@.v~ -1 P1m.¢.N QQ@@m1QQ=Q ~@~HQ~1@Q@~-=QQ;Q 1- -1 -1 11 1- 1- Q -1 -1 Q-m.Q.~ QQ@@m-=QQ;Q 11 -1 -1 QQ.Q 11 1- 11 -1 -1 Q1m.Q.~ QQQQQ @~.N Q1 mQ.m Q Q Q Q Q ~w.~ sm~o~u@m 1 Q-Q.Q.N EQQQQQQQ + Q-m.Q.~ Q~.~ Q Qm.m Q Q o~.~ Q @m.c _Q.Q QQEQQQQ QQEQQQQ Q Q ~Q.~ Q Q Q Q Q Q QQEQQHQ + Q-Q.Q.~ QQEQQQQ + P1m.¢.~ 1- mQ.Q 1 -1 Q 1- -1 1- 11 Qm.~ AQQ P1m.w.~ AQQ Q-m.Q.~ Q Q 1 Q<.Q Q Q . Q Q Q Q e1m.w.N 1 Q-m.Q.~ -¢v AQNQ AQQQ AQNQ AQHQ ~m.QmQ A-v AQQQ AQNQ @Q=Q=@Q¢HQz QQQQQ=H owcoa QQQHQQOZ owcoa QHQHQGOZ MCQEQQQMP m~@om zofifiazm m~@om mama n ~nm\:<ufiumnmo mc@>wnmo flmfiwwcfi can upflm >2 ao>ou xmocmu mpfisvmuz m.wQm~ .mmxoe . wwflnfimwm ~mn~:ou zwaoz map co no@po@ mc@=:m~m amm»1o~ m no>o fimumflfion wwmflv mwuwhfi oflppmu u2o\@~ wcfiwoopn wmuwm mam mo>Hum=»ow~m ~onp:ou opfizvwos zmcoc nmuowflmw cw w:oE~mo>:@ osw co cwzuoa we mwmu ~m::cm wm Q w:Hw~@H> new wmafiswmn AoaoQ\wv comuuswma pmoo ~mH~@:H .m~ @~nmP I9 D 88 wcfi ova. omwmaucfl .~oau:ou> man ca opmm>:~ ~m-mmu o m -@ k0 ownm.u pmmaopca wm m mmssmmm wsfi .@ n u . = Q . w . . @ cu M 1 . 0 .mo@uomw wowmmwm mo oa:px@E o>@umz U .>mnmm ~mwmn moumufiwcw zuficz any @|m.v.~ was oaum\nH m.o um mmfifimmm mm: sows: Emao~uHm + P|m.v.~ wmooxw onum\n~ ~@.o pm @@@H@@@ >-m@nom moc@o@nno: A .wow=o@xo cofipmnomo can m~mE@:m m> pcowmnm pm: one m a@=oa< mmmm mcmnmoum zpwam czoam xumw ammw@ ozwmwcoz msucweou moflwcsou ~muHm>e -- -- -- -- -- -- @~.¢@ ¢~.~m -- e|m.<.~ Q@@@m-@xm~-=o~@ Hoax m@.mm -- ~¢.¢m -- -- m¢.@m -- -- -- @=~@ @@@@m-@¥@~-3oH@ Qoom I- »| 1| || -| ¢@.@~ »| @¢.Nw -1 nsau mmm~wmw:e»om|oxma|zo~@ weom -- -- -- -- -- -- -- @w.v~ -- @:~u wm@~u=@@~¥-@#--zo~@ “com ANQV “GNU Ammv “GNU Away Am.@mv -- AQMV Ammv @u=@=@p=H@z -@~@¢H omcoa owmnowoz omcoc ouwnowoz . npcoeumoak mdwcm 30-m:m m~@om QQQQ ~n>\:<\mosumv >w@ommwo mcwxaamu Hmfiwficfi can ouflm >2 ao>ou xmocmu upflswmoz .@@==H~=¢u .a~ Qfipmb 89 except chaining and seeding native grasses , for a 9 percent annual rate of return to be realized. Cost reductions for mechanical practices ranged from 6.01 dollars per” acre for tree dozing, raking and maintaining improvement with basal applications of 2,4,5-T on shallow sites with initial carrying capacities of 2O acres per animal unit per year to 64.79 dollars per acre for root plowing, raking and seeding native grasses on deep ‘sites with initial carrying capacities of l7 acres per animal unit per year. Averaged across all sites and canopy cover situations, increased annual net cash flows were 1.75 dollars per acre following aerial applications of 2,4,5-T, 1.61 dollars per acre following application of 2,4,5-T + dicamba, 1.31 dollars per acre following application of dicamba, and 1.53 dollars per acre following 2,4,5-T + picloram applications (Table 30). Increased annual net cash flow from mechanical practices ranged from —0.52 dollar per acre on the lower productivity soils to 7.50 dollars per acre when high potential sites were root plowed, raked and established to coastal Bermudagrass. Average number of years required to recover the initial investment in aerial ‘application of herbicides was 8.2 for 2,4,5-T, 9.6 for 2,4,5-T + dicamba, 12.7 for dicamba, and 12.4 for 2,4,5-T + picloram (Table 31). From l4 to more than 2O years were required to recover the initial invest- ment in Inechamical practices for honey mesquite control on the North Central A Prairies . Annual beef production under "brushy" conditions was 16.1 pounds per acre, and production responses were relatively high following honey mesquite . control on the North Central Prairies (Table 32). 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On the average, herbicidal mesquite control with aerial applications of 2,4,5-T, 2,4,5-T-+ dicamba or dicamba was estimated.to result in a total annual weaned beef production of 24.3 pounds per acre. The 2,4,5-T +-picloranzcombination was slightly more effective, relative to beef production, than other herbicide treatments resulting in an annual production of 25.3 pounds of beef per acre per year over the 20-year planning horizon. Blackland Prairies The Blackland Prairies occupy about 11.5 million acres (Table l) and are typified by nearly level to rolling topography. Elevation is 250 to 700 feet, annual rainfall is 30 to 45 inches,and the annual frost free period is 230 to 280 days. Nearly half the area is cropland and a fourth is used as tame pasture and meadows. There are less than l million acres of rangeland- Upland soils are dark, calcareous clays. Bottmland soils are reddish brown to dark gray, slightly acid to calcareous, alluvial loams to clays. The ulands support tallgrasses with scattered stands of honey mesquite and.oaks, and the bottomlands support stands of oak, ehn QQ@§§_spp}). cottonwood, and native pecan. It is estimated that only about 538,000 acres of the Blacklands in native range are infested.with mesquite. In addition, a considerable amount of abandoned croplad is being retuned to native range use. Based on average aual brush control activities from 1973 to l977, about 15,500 acres per year are treated with herbicides on the Blacklands,and.mechanical methods are applied to nearly 38,000 acres each year. 97 Annual rates of return ranged from 10.9 to 13.5 percent and.averaged about l2 percent for aerial application of 2,4,5-T for honey mesquite control on the Blachland Prairie (Table 33). Aerial applications of 2,4,5-T + dicamba yielded 9.9 to 12.5 percent annual rates of return on the investment in.brush.nemagement. Dicamba, the "next best" alternative to 2,4,5-T (or herbicide mixtures based on 2,4,5—T),yielded 7.0 to 9.5 percent (average 8 percent) amual rates of return. l Mechanical treatments yielded annual rates of returns less than 5 percent with root plowing-seeding returning the highest (4.6 percent) rate on the investment (Table 33). Establishment of tame pastures to coastal Bermudagrass or kleingrass yielded annual rates of return only 3 to 4 percent,primarily because of the high cost of establishment (125.00 to 150.00 dollars per acre) and annual fertilizer requirements (Table 34). The following adjustment factors, as discussed for the High Plains, may be used to estimate rates of return fornathe honey mesquite alternatives (within a range of cattle prices from.34 to 54 cents per pound: Alternative Adjustment factor 2,4,5-T 0.64 2,4,5—T (B) 0.28 2,4,5-T + dicamba 0.63 Dicamba 0.57 2,4,5—T + picloram. 0.66 Shred 0.49 i011 0.33 Tree doze-seed natives (2,4,5—T as maintenance) 0.20 Tree doze-seed natives (grub as maintenance) 0,27 D 98 coflumfimcfimwizmwm MWQUOHQ mi? 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No reduction in initial cost of ' ‘ aerial applications of 2,4,5-T, 2,4,5-T + dicamba, or 2,4,5-T + picloram were required to yield aéipercent annual rate of return for honey mesquite control on the Blackland Prairies(Tab1e 35). However only on the more productive sites did applications of dicamba yield a 9 percent annual rate of return without necessitating a reduction in treatment costs. With other canopy cover/site situations, cost reductions of 1.70 to 2.86 dollars per acre were required for dicamba to yield a 9 percent annual rate of return. All mechanical treatments required a reduction in initial costs to yield a 9 percent annual rate of return (Table 35). The more intensive treatments such as root plowing, raking, and establishment of coastal §ermuda- grass pastures required reductions of as much as 119.53 dollars per acre, a 90 loarcent reduction in initial costs, in order to recover the investment and yield a 9 percent annual rate of return. Aerial applications of 2,4,5-T generated increased annual net cash flows of 1.46 to 1.94 dollars per acre for the investment in honey mesquite Q control on the Blackland‘ Prairies (Table 3e). All other herbicides aerially applied, generated positive increased annual net cash flows, and averaged 1.58 dollars per acre for 2,4,5—T + dicamba, 1.30 dollars per acre for 101 new ouom\n~ m1o~m wm@~mmm mm: cows: Emno~u~m + e1m.¢.~ wmmuxo wommwnucfi .~o~p=oo smsun cw wmpwo>c@ flmpwmmu wowwm fifim now omnmnu .no@uomm uopmmwm mo QHDHXME o>Hpmz U .>m»mm ~mm@n woumufincw sows: Amv P1m.w.N 0HUQ\Da >o.o.wm wo@~mmm >-mwnom MQQMUMQHQI A .mom:mmxm cowumuomo was m~mE@:m wcfiwoonn HWQHOHCM NQ G MOEDWMM ®5~G> HCQWQHQ HQC 05% M comuaonom -fi: comflwmz Qonwmmm =omm~n:m wowpcsou ~@Q@@>@ -.~@ mm.@- m¢.ww 11 wm.mm .mv F1m.¢.~ wm@~m@@=e~@m-@¥@~-=o~@ poem m@.w@ w~.~¢H ~H.N~ 11 mo.mo nsnw wmm~u=@@HX1@¥@~1=o~@ »oQ¢ 11 -1 -1 mH.¢m 1- any @-m.v.~ u@@@m1@¥¢~-;o~@ ~¢¢¢ 11 wm.~N 11 11 11 nsuu owoom13o~m poem 11 mm.mo. 11 11 11 nzau mmmnwc@o~x1o~ow oouk 11 11 11 mm.m¢ 11 h1m.v.~ ocomm12o~m ~oo~1o~on monk 11 ~m.m¢ 11 11 11 nsnu uwuom1m~ow omae -1 1- 11 11 w@.@m ~mv.P1m.¢.~ Q@@@m1@No@ Qwgk 11 11 11 om.m 11 fifio awe 11 11 11 11 ~Q.¢ wwhzm wmpzm 11 o 11 11 o emuofluwm + k1m.v.~ E¢~o~u~m + e1m.v.~ o~.~ @w.~ m>.~ 11 o mnemufie @@e@UHQ ¢ o ¢ -1 ¢ mpemuww 1 @-m.¢.~ mnemofiw + @-m.¢.~ 11 w@.@~ 1- 11 @@.¢~ Amy @-m.¢.~ Amy @-m.¢.~ @ ¢ ¢ 11 ¢ @1m.v.~ P1m.¢.N hcmv fim~v ANNV HNNV .~m~V @U=~=@p=@mz H@M-=H mm=oa1o~m~@woz mmcoa owmnowoz nycosgmohw m_@¢m zaflflmgm m~wom mama ~nx\:<\moaomw1»u@om@mu wcwxnnmo ~m@w@:@ can muflm >@ po>ou >@o:mu oufisvmoz Q ew~m~..mmxoH .mOwP@9P=©¢m~xomHm on» co vofinom m:@=:m~m amo>1o~ m no>o ~mnmH~ow wnmfiv wmufiam ofluwmu u3u\v¢w can mcoflumnomo w~mu12ou co woman xuouwo>@~ ucfluoonn wowwm was floawcoo ouflswmue >@=¢= cw u=oEumo>:@ mcw :o.ca:~on mo mums ~m:=:m wm m m=@@~@@> new mwcosumwau flmwuwcfi wo.~oaum\»v cowuusuoa umou .mm oflnme Q. 1! 102 H. i can @nom\n~m.o Hm wuaflmmm mm: sows: smnofiuflm + P|m.¢.N wmouxo waom\n~ >o.o aw wwfifimmm >-m@nom mow@uHn~m: mm: mzofim. A~MGU MO MGMEMH 05H UCM UQUDMUGM HOG Mk0? WQNHQSU wmonoupfi @- .mowoo@m wouumwm mo onswxwe o>M~mz u .>@»@m ~¢w@@ wwwmwflwzfl zufizz Amy P-m.¢.~ Q .ww»@u@m:ou we: .:o~Hno: w=@¢=@~@ nmo>1o~ oz» mo wcm osu um ~m~nmu@~mmm wfiv ~onu:ou amass wcm mzou mo @:~m> omm>~mm ms» m:~m mumou mcfiuwammo ~m:::m wommoaocfi van _xuoum0>- w=@w@@~@@@@@¢.*¢-=ou swans mo wwmou mmoH Ap3u\vwwv woflmm ammo nouns Mayo» mfi 3oHm ammo pm: oak m mm@w::ou fimofimxk Gomuhmflom H~@: comflwmz monuwmm cowm~n:m ll. H~.m ~o.m w~.o || ~o.m flaw P»m.v.~ mwm~wmw:En0m|wxm~|2o~Q uoom ~v.m ~o.< mo.w || wm.m nnuu mwmhmcfioflx-mxmu|2o~m wooz || 1| nu‘ m~.H || Amy h|m.v.~ ovwom|ozmn|2o~m poem -1 ~m.N || 1| '1 nave @oom|2o~m uoom || ¢m.v I» »: '1 nsuu mmmnwmmm~x|m~ow QQHP “ »| || vm.~ -| h|m.v.~ Hwoomlzofim uooa|w~ow ompk 1| w~.~ || =1 || nape huvo@m'o~ow weak 1| :1 |: || ow.o| ~mv.P-m.<.~ onvmmlouow ooak 1| 1| :1 oo.~ || ~HO Mao || 1| || »| ~@.¢ vonnm consm -- ~w.~ -- -- @¢.» Em~¢~QH@ + @-m.<.~ Emkofluflm + P-m.¢.~ w~.~ m~.~ ¢m.~ || @m.~ wpemufim wpemufia ¢¢._ @m.~ ~@.~ -- @w.~ mnewuflw + @-m.<.~ mpewuflw + h-m.¢.~ -- w~.~ -- -- @w.¢ Amy @-m.¢.~ Amv F-m.<.~ ~m,~ @<.~ o>.~ || ¢@.~ @-m.<.~ @-m.¢.~ Aomv Amwv fiwmv Awmv ~m~v oucmcopcfimz ~m@-:~ om:mo|oum»uwo2 mwcmo oumpowoz nucuswmoph mfiflom zofifimzm ouwm xn uo>ou >@¢=~u owflswmoz mdwow moon ~n>\:<\monowv »wMQ@m@@ mcflxnnmu ~mwu@:@ vcm ..w>a~ .wmxoP .mmM#@npm wcaflxumflm mzw co :o~@noz m=@==@~@ ~@@>-¢~ m no>o fimoufiam wwmflv woufiam o-umu ~=¢<¢<» gm wcofiumnomo w~mu -300 co momma wo>@um=aou~m ouflswmoe >@¢¢= wowoofimw scum ~mnum\wv 2o~m ammo won ~m:::m wummo~o:~ .@m Qflnmk 103 dicamba, and 2.44 dollars per acre for 2,4,5-T + picloram. All mechanical practices resulted in increased armual net cash flows except tree dozing and seeding to a native range mixture. The greatest increase in annual net cash flow occurred following root plowing, raking and establishment of Bermmdagrass or kleingrass pastures. From 9 to ll years were required to break even oninvestments in aerial applications of 2,4,5-T while 13 to l7 years were required to recover initial investment in dicamba for honey mesquite control on the Blagkland Prairies (Table 37). K11 but two of the mechanical alternatives required at least 2O years tobreak even on the investment. These extensive payback period requirements increase problems for the land manager in secturing capital to undertake such range improvements. Total annual weaned calf production over the 20-year planning period was nearly doubled by the herbicide treatments and increased more than six times by the mere intensive mechanical alternatives compared to pre- treatment production levels (Table 38). There was little difference in annual beef production among the aerial herbicide treatments ‘vahich averaged 28.2 pounds per acre across all site/mesquite canopy cover situations, compared to 13.9 pounds per acre, on the average, before treatment. of the honey mesquite. Although establishment and maintenance costs were high, exceptionally high average annual beef production levels resulted from the tame pasture alter- natives (Table 38). On the most productive sites, those with carrying capacity of 1 animal unit per 22 acres before treatment, establishment of ' Benmudagrass increased the average armual beef production to 93.6 pounds per acre, and kleingrass pastures produced 56. 9 pounds per acre, compared to 14.1 pounds per acre before treatment. These high production responses help wcm onum\n~ m.oum wofifimmm mm: cufisz Ew#o~u@m + P|m.¢.N wmooxo onom\n~ ~w.o um @@W~@@@ >~HmHno@ wmwfiufinpmz ow woawsvm» an -@3 mama» om cmsw nmumonw mowmuwwcfl + ow < _.. i mi .wo@oomm uoummwm we onswxwe o>@wmz u .>m»Qm ~mmmn mopmufiwcw suds: Amy P|m.v.N n .p:oEpmo>:H ozu ~o>ouon :.xumn|>mm: mo QEMH ocu um =@@~@~@@¢ oz» ow mcasuoa mmoum pcommnmma wfisoz was .uo@~@m w:o|>mQ ocu we wawm mm wowsfiucfl yo: mam ~o~nmu@~mmm wfiv ~onucoo .mm@~@::u~ommo ~:oE~mo>:@ wwm:~m>@ op wow: xflcossou zwofinom xumn|>mm: smswn wcm mzou mo wo:~m> mwm>~mm w wucomonmwa uownom mafia one .wo@:~u:H ohm momnmzo pwmnoucfl oc vcm w@~@~@~: mm: coufinoc m=M==@~@ nmm>»oN < m COmHHOflOM MHMI comfinmz monummm comofinsm WQMMCJOU ~muwQ%P + ow + ow om ll * + ow Amy P|m.v.~ mmmwmww:Epom|mxma-2o~Q poo: ad + ow ow || ow nnpu wwmpw=@@Hx|@xwp-2o~m Hoom -- -- -- QN -- Amy @-m.¢.~ Q@@@m-@x@~-3oH@ ~Qom || w~ I- || I1 nswu onoumlzofim Hoom 1| + ow || || '| nsuu mwmuwcHm~x|oNow Qwhk -1 I1 || om |» k|m.w.~ unomwlzofim ~oo~|o~ov QQMF 1| + ow 1; -| -| nsnu nwmm-@~ow QQMF -- -- -- -- + QN ~mV.P-m.v.~ m@@@m-@~o@ @@- 1' »| || mfi || fifio fiflo || || I- || mfi wwpgw wmgsw || o~ 1| 1| m Em»o~u~m + ~-m.<.~ Empofiuflm + P-m.¢.~ nfi @~ vfl || mfi mpewufim mpawufig - Hfl m || m mnemufiw + P-m.<.~ wpemuflw + @-m.¢.~ »- @~ -- -- + ow flaw @-m.¢.~ Amy P-m.¢.~ - ¢~ m -- @ @-m.¢.~ P-m.¢.~ ACNV Am~v ANNV ANNV Am~V @@=w=@~=H@z ~w@~@=~ @m=oc»o~n~owo2 mmcmo mumnowoz pcweumuwe m~@ow 30-fl£w mfiwom mums ~»>\=<\m@~wmv.»»@Q@@@u mcflxnnmu ~m@u@=M mam ouflm >@ au>ou xmocwu ouwnwmwz n 104 m.wmxoP .moM»@m»@ n=m~xum~m oz» co wofiaom w=@==@~@ ~@@>-¢~ m ao>o ~w»m-ow w~m~v moufiam ofluumu uzu\vvw co woman cofiumammo w~mu-2ou scam xuowmo>@~ mcficooan ~m=o~u@uum wcm ~oa»:ou owflswmoe >@=¢= cw ~:oE~mo>=@ flmfiuflcfi osw ~m>ouon ow wowwswmu mnmw> .~m Qflpmp 105 .mo@oomm UQHQMUM MO ®%DHXfiE 0>wHdZ .>mamm ~mm@n mmpmufiwcw UH 2 1 . . wcm mauw\n~ m.o~a @ofi~mm@ mm: seas: Emaofiufim + P1m.¢.~ pmouxm maom\n~ >@.o uw woH~mmw >_“@Wm@@fiMW@%QM@W@m .om=ommon cowwuswonm owmnm>m asp QCMEHQHOU ow vo~@~@u: mm: uofinom mc@::m~m nmo>|o~ < @ U =¢m-@@¢¢ ~H@= =¢w@@@: @o-m@m =om@HH=m m@@~==¢U _@U@@»P w.o@ ~.~> @.m@ -- @.m@ any P-m.¢.~ mm@~m@@=E~@m-@¥@»-=oH@ poo“ @.@@ ¢.~w @.@m -- o.~m p=~u mm@~»=@@~¥-@¥¢»-=o~@ »oo¢ -- -- -- m.@m -- Amy P-m.¢.~ Qw@@m-@¥--3oH@ poem || m.om 1| || '1 nsuu .vwow|3o~m uoom || ~.~> || || 1| nzuu mmmuwmwo~x|m~ow monk 1| || || ~.~m -1 P|m.w.~ .uwomm|2o~m uoo~|m~ow vmuh -1 ~.om »| 1» '1 nsno uwoom|oNow QQMP -- -- -- -- ~.~m AmV.@-m.¢.~ Qw@@m-@~¢@ Qwkp -- -- 7 -- ¢.- -- flfic Hflc -- -- -- -- ~.- @@»=w @@~=w -- ~.¢~ . -- -- >.@m E@~¢_Q@@ + @-m.¢.~ Empofluflm + @-m.<.~ m.¢~ m.- ~.¢~ -- m.~< QQEQUMQ @@E¢U@Q m.¢~ m.- . ~.¢~ -- m.~¢ mnemvflw + @-m.¢.~ mnemuflv + P-m.¢.~ -- ¢.¢~ -- -- ~.<¢ Amy @-m.<.~ Amy @-m.¢.~ m.- m.H~ ~.¢N -- m.~< @-m.¢.~ P-m.v.~ Nlm N.- H.v~ ¢.m~ m.o~ -=@E~@@-@~@v wcoz AQNV ~m~v ANNV ANNV flmfiv @U=~=@~=@~z ~m@»M:~ wmcoalopmuowoz omcoo opmpowcz wcospmonh m~@om 3o-m:m mflflom @000 . D ~n»\:<\monocv »~fiQ¢-un ~o>ou xmocmu opfiswmoz m.wNm~ .mmxoP .mo-@mp@ w:m~xum~m osu co m:o@~mpm@o w~mu|3oo co woman m@>@~m:hvu~m ~oau:oo ouflsvmms >@=¢= mmuoo~om scam ~nmu>\oauw\n~v cofluoswoum w~mu wwcmoz ~mpoP .wm m~nmP l Q explain the application of mechanical practices to more than twice the acreage treated with herbicides. Mreover, the production of herbicide sensitive crops on the Blackland Prairies is a constraint on chemical brush control on rangeland. Texas Claypan The Texas Claypan covers 8.5 million acres of nearly level to gently rolling land in the east central portion of the State (Figure 1). Origi- nally Post Oak Savannah, it is often referred to as the "post oak belt." Elevation is 200 to 500 feet, annual rainfall is 30 to 45 inches and the annual frost-free period is 235 to 280 days. The uplands are typified by gray, slightly acid, sandy loans over mottled or red, firm, clayey subsoils. Reddish brown to dark gray, slightly acid to calcareous, loamy to clayey alluvial soils are conmon on bottom- lands. Only about ll percent of the Texas claypan is still in native vege- tation (Table l). Row crop agriculture, tame pasture and more recently, urban development, account for most of the land use. Few ranches operate with Icow herds larger than 200 head CTableI3). Vegetation is dominated by scattered stands of post oak (Quercus stellata), blackjack oak (gggrcus marilandica) and mid and tallgrasses. The primary brush problems are post oak and blackjack oak in association with yaupon (llg§"wonitoria), winged ehn (§Qmg§_alata) and various other woody species in an east Texas "mixed— brush" complex. Honev mesquite occurs on about 33 percent of the ranfie’ land, prinarily on abandoned cropland which has been allowed to revegetate ‘v naturally (Table 1). Most of the mesquite stands are almost pure, even- aged, and of moderate canopy cover. Also, most of the mesquite infestations 107 occupy relatively small blocks of land, usually less than 150 acres, which has some bearing on choice of treatment for range improvement . Therefore, compared to vegetation regions previously discussed, relatively few alternatives were evaluated for honey mesquite control on the Texas Claypan. According to Hoffman (1978), fron11973 through 1977, about 13,300 acres were treated annually with herbicides for brush control on the Texas Claypan, and about 44,350 acres received mechanical treatment. The pre- ference for mechanical brush cotrol is indicative of the annual rate of conversion of rangeland to tame pasture on the Texas Claypan. Annual rates of return were higher from aerial applications of herbicides than from the mechanical alternatives (Table 39). Averaged across canopy cover/site situations, amual rates of retuns from.aerial application of herbicides were 11,9 percent for 2,4,5§T, 10.9 percent for 2,4,5-T-+ dicamba, 9.3 percent for 2,4,5-T*+-picloram, and d.3 percent for dicamba. Tree dozing followed by basal 2,4,5-T sprays produced negative rates of return (average -3.1 percent). On the average, establishment of tame pastue yielded only 1.9 percent annual rate of return. Annual rates of return from the alternatives can be estimated for cattle prices of 34 to 54 cents per pound, as discussed for the High Plains, by applying the following adjustment factorsz. Alternative Adjustment factor 2,4,5-T 0.63 2,4,5-T~+ dicamba 0,61 Dicamba 0.57 2,4,S- T +-picloram, 0,59 Tree doze 0,21 Root plow-rake-kleingrass 0,31 Root plow-rake-Bermudagrass 0,27 .mmwnmmu:Eaom Amuwmou ow wo:m@Anmumo oanummm osmku .»mnmm Amman mowmuwwcfi cows: Amy e|m.¢.~ wcw oaom\nA m.o um noAAmmm mm: sows: EQMQAQAQ + P|m.v.~ wmouxo oaum\nA ~@.o um woAAmmm >AAm@nom mowflufinnozn .AAAw:¢o mcnsuon wcm mumou uoowwm AAA: =oApmAwcA moaswmm wmmuoam mfick .mouma Amok ocw ow opma :oAwmAw:w umesmmm cm wcwnwm An oums an Ame CHZHQM mo woman Amcfisoc no woxams mo opwefiwmo c< .:»:uoa mo oumn Anon m wwaouflmcou ohm cam wpumnefl :oA~aAw:A uw:Au:@ wo: ow cpswou mo mo~mn.Am:::m .w::@ .mamAAow w~mA pcmpmcou cm wmpuonohm @803 mcnswon vcm mumou .mQ¢mm@>mm wcwuoonn wcm Aoaucoo swans cm Amufimmu p:oEpwo>cA ncm wcfiwmaomo AAQ maowmmcou cnswoa mo mums oskm :@um:< wommnm ouq moumnm wofiwcsou AQQAQAP m.m m.m m.A m.~ Amy m-m.m.~ mmmmmmmm=E~mm-mmmm-3¢Am moom -- »- m.~ m.~ Amy m-m.<.~ mmmmm=m@mm-@mmm-momm moom -- -- m.m- m.m- Amy mrm.<.m mmcm mmmk m.m A.m A.mA m.mA Emmommmm + m-m.m.~ Emmommmm + @-m.m.N ~.> m.m m.AA m.m mmemomm mmemumm .m.mA m.A ¢.mm A.NA mmammmm + @-m.m- mmmmumm + @-m.m.m ¢.AA ~.m m.mA A.mm m-m.m.~ . m-mm¢.m Ammy Ammy Ammy |,Ammy @U=m=mm=mmz Ammmmmm omcwa mumnonoz owcoa opmnwwoz pcoepmowe wAAom 2oAAm:m wAAom moms n .mmw:<\wonomy xuwummmu wcflxnnmo Awfiuficm ucm o~Am An »w>ou Amocmu mwwsvmoz .w>mA .cwm>mAu mmxoe map co coAaom m=A==mAm ~mo>|o~ m »o>o AmamAAow w>mAy moufiam oAupwQ p:u\¢ww pm cofipusnoam m mAwu|2ou co woman mm>Apm=nmpAm Aonucou opmswmme Ammo: wouooAom Eonw Awy cnspoa mo moumn Am::=< .mm oAnme 109 Thg law annual rates of returns from.the mechanical practices can be attributed to the relatively high initial costs for establishment of coastal Berrrudagrass or kleingrass tame pastures, and the high c0813 Of $111081 fertilizer and other maintenance practices CTable 40). Average initial cost for establisment of tame pastures ranged frcn1ll5 to 160 dollars per acre. The cost for herbicides was the same as for the Grand Prairies and Cross Timbers (Table 22). Since most of the deep, productive agri- cultural soils are established to row crops or as small grains pasture, the "better" rangeland soils also require annual inputs of fertilizer to nmintain pnuductivity, especially for tame pastures. No reduction in costs were required for aerial applications of 2,4,5-T to yield a 9 percent annual rate of return on the investment (Table 41). No cost reduction was required for the other herbicide alternatives to yield a 9 percent annual rate of return.when honey nesquite infestations on deep soils were treated. However, reductions in.initia1 treatment costs were required for all mechanical alternatives to yield a 9 percent annual rate of retun, ranging from 58.67 dollars per acre for tree dozing maintained by basal sprays on deep soils tx>l2®.ll dollars per acre for establishment of coastal Bermudagrass in the Lee county area. All honey mesquite control alternatives increased annual net cash flows, except tree dozing maintained by basal sprays of 2,4,5-T, on the; Texas Claypan (Table 42). Annual net cash flows, averaged across treat— ” ments, were 1.62 dollars per acre for aerial applications of 2,4,5-T, 1.56 dollars per acre for 2,4,5-T + dicamba, 1.34 dollars per acre for dicamba, and 1.50 dollars per acre for 2,4,5—T +-picloram. Negative annual cash flows resulted from tree dozing followed by basal spraying of honey mesquite on deep sites. Establishment of tame pasture on deep soils nan oaum\nH m.opc wmfiflmmm mm: coax: Ewnofiufim + P;m“¢.N wmouxo o»um\n~ no.0 pm wofiflmmm xfiflmfinom mowfiudnaoz .mmmammw:Enom Hmpmmou op @osm@~nmpmo oasummm weak 0 .>m~mw flmman mmpmuwwcfi sows: Amv P|m.¢.~ h? .mw:o=5mm>:~ xuopwm>fi MCMUQQHQ ©0006 ®~uD~UCH HOE 0U mwmoo HCQEHMQHH HGMHMGH w c@um:< mowanm . ooq moumnm mwflpcsou ~mu@@>P oo.om~ oo.om~ oo.oo~ oo.om~ Amv P=m.w.N u mwm~wmw:Eaom|mxmu~3o~Q poem || .|| oo.m- oo.mH~ Amy @-m.¢.~ wmmam:@oHx-oxmn|2o~m poem || ll 00.00 00.0w Q0 .._..|m~¢.N QNOU QQMP 8S S2 32 S: wémempfimz 25d: wwcwm opmgmwoz omcoo owmnmwoz @~=@s~@@»@ .LL. m~@om zofiflmsm w~@om mama axw:<\monuw0 xuflummnu mcwaasnmo Hmwpwcw cam o~@m xn »o>ou >@¢=@u uwwzvmoz .w>m~ .:mm>m~u mmxub on» new no~m:~m>o mo>@~m=ao-m Hoapcou opfiswmos >@=¢= mo ~o»um\»0 mpmou ~mwp@:~ .o¢ ofinmw 111 .mmmnmmm:Enom fimpmmou ow cosmwfinmumm onspmmm Qsme @ .>@~@w Hmmmn w@~mQ@@=fi =QH;= Amy k-m.¢.~ mam maum\n~ m.oum um@~mmm mm: sows: Emaofluflm + P|m.w.N umooxo onom\n~ >o.c um noflfimmm >H~m@nom mwnwufinwoz n .Hon»:ou swans cfi wo~wo>:@ ~m~@mmu wouwm ~Hm new wwnmcu wmowmucfi wm m mmssmmm o:~m> pcommnm um: oak m .momcomxo cofiumwwmo wcm m~mE~cm mcfiwoonn wommonucfi =@wm:< mo~wnm ooq moumam wofipcsou flmufigxe Q¢.-~ ¢¢.@~H -.¢~H -.m¢~ flmv ~-m.v.~ Qmm@~m@@=E~@m-@¥@~-3o~@ Qooa 1| || mw.¢w om.m~ Amy P|m.w.N mmmhw:fio~x|ozm~|2o~m uoom -- . 1- ¢m.m~ ~@.wm & fimv P»m.<.~ @~ow mug? @H.¢ >~.~ o o Emao~u@Q + P|m.v.~ Emwofiuflm + P|m.v.N H<.H <~.m Q Q mnsmufia maemufla ¢ w~.¢ ¢ ¢ mnEmuHn + @-m.¢.~ mpamuflw + P-m.v.~ ¢ ¢ ¢ ¢ +-m.¢.~ »-m.v.N AQNV A@~v ANNV AWH. @Q=@=@~=@@z _mH»@=H mmmmm owmkonoz omcua opmawwoz npcmspmmge m~@om zoflfimzm mfiwom mmwa Amx\:<\monomv zuwummmu w=@>-@Q ~m@u@:@ mam mpwm >@ ~o>ou xmocmu owfiswmoz .w>m~ .:mm>m~u mmxoh ozu co woflwom w=H==@~@ amox|o~ m no>o Amnmfiflow w>m~v moufinm o~p~mu ~3o\wv» mam cofipmaomm m~mu|3ou m co woman xuowmo>wH mcfinoonn wovmm ucm ~onu=ou owfisvmoe xmcom cfl pcoe »umo>:@ oz» co campus mo mama ~m:c:m wm m w=@@~@@> pom uwnwsvoa ~onum\wv co@uu:uma.uwoo ~mm%@:~ fiq ofinme 112 v i dmmnwmnfienom MQHWGOU OH moswxnmumm QHUHmQQ QEGP U .>maQm fimmmn mowmuflncfi aoflzz Amy P|m.w.~ wcm oaom\n~m.o pm wofiflmmm mm; sown: Emmoflufim + P|m.¢.N pmouxo o~ow\n~ no.0 pm wm@~m@m >-mHn0m mowHu@nno: n .wou@@@m:ou uo: mm: mzofiw ammo we wcfiafiu on» w:m.wow:~o:@ Ho: opoz momamzu umonowcfl .CON@HO£ w=H==@~@ ~wo>|o~ map we nco wzp pm fiofinm |@~mmm wfiv ~on¢:ou zwswn mam wzou mo w:Hm> mwm>~mm ozu msflm mwmoo wcfiwmnomo flmszcm w@mmw~u:@ w¢w xuowm |o>@~ mcflwoonn uowwm .~onu:ou swans mo muwou wmofl ~u2u\¢¢wv wofimw cmwu wovnm flwpow wfi 2o~w smmu pm: axe m \ c@um:< mowmam ooq mo~@nm mvflpczou _mu@Q>P H¢.~ @¢.~ @m.m ~w.¢ flmv P-m.<.~ Qmmm~w@@=E~@m-@¥w~-3o~@ “cox -- -- A¢H.m @¢.m Amy P-m.v.~ mm@~w=@@~¥-@¢@~-z¢HQ Hoom -- 1- ~<._- ~m.~- flmv @pm.¢.N QNOU wank m~.~ oo.o om.~ -.~ Empofluwm + %-m.v.~ Empofiufim + @-m.¢.~ m@.¢ @m.¢ ©©.N Nv.~ wnsmufic mpsmuflc -.~ >m.o om.N ~o.~ mnewufin + P|m.w.N mgsmufiv + P-m.¢.~ .-.~ m@.¢ ~@.~ m~.~ @-m.<.~ +-m.<.~ .|wwWw Aowv ammmw Amflv mucmcowcwmz ~m@p@:H wmcmo opwkonoz omcoc QQQMQUOZ pcmepmuhw Q w_~om 2o-mzm m~@om mama ~u>\:<\mmnumv xvwumnwuvmcwxanmu Hwwuwcm ncm owdm >2 »o>ou >mo:mu Qwwswwoz .w>m~ .:mm>m~u mmxoh on» co woflaon w=@==¢~@ »@@>-¢~ m no>o ~mn@-ow wnmflv mooflum wfiuwmu u3u\vvw ncm m=o@umn@mo w~mo|2ou co woman mo>@~m: |nou~m ~on~=ou owfiswmme >@=¢= wwuuwfiom >0 wmuzwoam ~amo>\waum\wV 3o~w|:mmu um: fimsccm wmmmwau:~ -~¢ ofinmk 113 resulted in an average annual cash flow increase of 3.30 dollars per acre for kleingrass and 4.12 dollars per acre for coastal Bermudagrass. Thus, comparing the least effective herbicide relative to increasing annual net cash flow, dicamba, to the most effective mechanical conver- sion, establishment of coastal Bermudagrass, there was only a 1.44 dollar per acre difference annually over the 20-year planing horizon. Yet, establishment of the tame pastue initially cost 143.65 dollars per acre more than the herbicide treatmnt. Mbreover, anual maintenance costs for the tame pasture option would more than equal total cost for herbicide treatnent, based on 1978 prices. Fran 9 to l4 years were required to recover the initial investment in aerial applications of 2,4,5-T or 2,4,5-T + dicamba for honey mesquite control on the Texas Claypan (Table 43). The break—even periods for dicamba ranged from.lO to 15 years,and 10 to l7 years were required for recovering the initial investment in 2,4,5—T + piclorant Time required to recover the initial investment in tame pasture establishment exceeded 20 years in all cases. Aerial applications of herbicides for honey mesquite control on the Texas Claypan increased weaned calf production by more than 61 percent, producing an average of 25.3 pounds of beef per acre annually (Table 44). Tame pasture alternatives increased weaned calf production from 15.6 Pounds Per a¢re annually to an average 61.8 pouds per acre per year on Bermudagrass pastures. East Texas Timberland The East Texas Timberlands, about 15 million acres of mostly forested lands, occupy the extreme eastern part of the State (Figure 1). Honey 114 w i .mmmnwmw:Enmm flmummoo ow nosmfiflnmumo onsummm oemh u .»m~@w Hwmmn m@~¢Q@@=@ goflgz “my P-m.¢.~ can onum\n~ mA~wm wowflmmw mm: suflcz Emnofiufim + P1m.v.N pmwuxm o»um\n~ no.0 um wuwfimmm >-mfiuom mouflufinuoz Q .HCOEHm®>GM wzp ~o>ooo~ ow @@»@=¢@~ on -@2 mnmmx ow cmcp aopmoam mmumofiwcw + ow < :.xuwn»>mm: we wsfip oaw pm cofiwmpomo o:~ op wcaswoa mwonu ucmwonmoa wfisoz was .@¢@~@@ ~:o|>mm map we pawn mm wmw:Hu:M woe mum fi@~@@Qfi~@@@ wwv ~o-:oo swans mam mzou mo mm:m~> mwm>~mm .mo-@::~»ommo ~:mE~mo>=fl @wm:~m>o ow wum: >~COEEOQ =@¢H~@@ xumn|xm@: m mucommnmou uofinmm mafia ash .won:~u=H mam momnmco pmowopcfi 0: cam wm~@~Hp: mm; co~@~o: w=@==@~@ pm@»|o~ < m =@~m:< mo~mnm 004 woNmnm m®HwC30u ~muwQxF + ON + ON + om + QN any @-m.¢.~ Hmm@~m~@=E~@m-@¥m~-=Q~@ “com -- %-- + ¢~ + ON fimv @-m.¢.~ wm@~m=M@_¥-@¥@~-:¢~@ Hoe“ -- -- + ON + QN . Amy @rm.¢.~ @~¢@ wmhk m~ >~ o~ ofl. empofiuflm + P|m.v.~ Empofiufim + e|m.w.~ mfi .m~ Gfi - QQEQUMQ V QQEQQHQ ¢~ w~ m ofl mnemufiu + P|m.q.~ mnamofiv + @-m.v.~ ¢~ ¢~ m o~ »-m.¢.~ P-m_¢.~ .|hmw~ AQNV ANNV hmfiv @U¢@=@~=Mmz ~@@~@=H owcma owmaouoz mmcoo owmamuoz npcospwopk mflfiow 2o-msm 1» mfiflow move ~aM\:<\moaomv xwwommmo wcwxnnmo ~m@u@=@ new opflm xn ~m>ou >@¢=~Q ogflswmoz w.@~@~ .=@@>@_u mmxoh mzw co ~mam-ou w>m~v woufinm ofiuwmu »:u\vvw new mcofipmnomo w~mu|2ou co woman xuo»mm>@~ ~m=o@~@wum mam ~o~u:oo opfisvmos »@=¢= cfi ~=oE¢wm>:H ~m@u@:@ asp no>ouo~ op @@~@=¢@~ mamo> .m¢ o~nmP 115 .mwmnwmusEnom Hmpwmou op uosmfiflnmumo oasummm weak u .>maQm fiwmmn mowmu@m:H suflcz Amy P|m.w.~ mam onom\n~ m.oum wo@~m@@ mm: cows: Emnoflufim + P|m.¢.~ unooxm oaum\n~ ~@.o um wofiflmmm xflfimwnmw moufiuflnnoz Q .mmm:ommon cofiuuzwonm @w@»@>@ mag ocfieaouou op wo~H~@»: mm: wofinmm w=M==@~@ nmo>|o~ < m c@um:< mowmam ooq mo~¢~m mofiucsou _muMQxk N.Hm w.¢m w.w@ m.@> Amy P-m.¢.~ Qmm@~m@@=E~@m-@¥@~-;Q~@ Hoax -- -- m.@m ¢.H@ fimv @-m.¢.~ mm@~m¢M@~¥-@¥@»-:¢_@ paoz -- -- ~.m~ m.w~ Amy @rm.<.~ @~o@ wwph @.~N Q.¢~ ¢.¢m m.¢m Empofiuflg + F-m.¢.~ E@~oHU@@ + @-m.¢.~ @.- w.wH ~.¢m Q.¢m mnemufio mnsmufla @.- w.wH ~.Qm ¢.Qm mnemuflw + h-m.v.~ mgamuww + E-m.v.~ @._~ m.» N.¢m ¢.Qm ~-m.<.N @-m.v.~ >4<~ “.¢~ .m.m~ @.@~ A Apcmepmoawoamv ocoz .|h@w~ AQNV |wmw~. flmfiv @U=@=@~=@wz ~@@p@=H omcmo oumnocoz omcmc mwmaonoz pcoepmopk m~@ow zofifimzm mfiwom moms n ~nx\:<\noau@~ xuwummmo wcflxaawo fimfiaflcw can uwflm >2 »o>ou xmocmu ouwswmoz .w~mH .cmm>m~u mmxoe ocu co cofiuuzwonm w~mu|2ou co wommn mo>H~m=a0u~m fionwcou oufisvwme >020: wopomfluw Eomw ~amo>\onum\n~v cofiuuswowm m~mo wmcwoz Hmpoh vq ofinmh _f nu .w 116 mesquite is not considered a problem.in this land resource area. Only about l percent of the resouce area is native range although grazeable forest offer a valuable forage resouce (Table 1). Most brush control activity occurs on forested lands,and mechanical methods are applied to greater acreages than are herbicides in East Texas. ‘For example, herbicides W é were applied to an average of about 7,500 acres annually from the periods 1973 through 1977 in contrast to application of various mechanical methods to more than 32,600 aCreSannua1ly (Hoffman.1978). It is estimated that relatively' few acres of the native range along the western edge of the East Texas Tnmberlandssnnnxnnrhoney mesquite stands. As on the Texas Claypan, nost of the mesquite stands are located on abandoned cropland. Although an exact estnnate was difficult to obtain, apparently most of the mesquite infestation is of light to moderate canopy cover Cfable l). Greatest annual rates of return were yielded by aerial applications of 2,A,5-T (13 percent) followed by 2,4,5-T-+ dicaba (ll.2 percent) and dicamba (8.2 percent) for honey mesquite control in the East Texas Timber- land ‘(Table 45). Dicamba was the only herbicide treatment that required an initial cost reduction to yield a 9 percent annual rate of return on the investment. Herbicide treatments increased the annual net cash flow by 1.15 to 1.58 dollars per acre and increased weaned calf production from 19.9 pounds per acre per year on mesquite-infested land to 30 pounds per acre annually. The only mechanical alternative evaluated for conversion of mesquite infested rangeland in East Texas, establishment of Benmxtmness pastures, generated a 4.6 percent annual rate of return. These analyses were conducted with beef prices of 44 cents per pound. To estimate annual rates of return among alternatives within the range of beef prices of 34 to 54 cents per pound, the following adjustment factors,as discussed for the High Plains, apply to East Texas: 117 .»p:sou H@Q@@>~ w mfi cooq .>m~mm Hmmwp w@~@Q@@=@ gofigz Amy @-m.¢.~ pmouxu onum\n~ no.0 um @@@_@@@ xfiflmfinom monfiownuoz u .>~o>@~uommoa .¢¢|mm mmflnmu mo Amy wwuocuoom cw nm:@m~mxo wo~nm@~m> now mwwmm A .nmo>\:<\monum mfl .>~@ummmu m=@>namu ~m@p@:H .no>ou >@¢=@u omcow ow opmnonoe mo wwm~o>m wmpmsfiumu -< . m wmmnwmwsswom H.~@ wfi -.@ ~w.mw @¢.m- @.< Amy @-m.¢.~ -@~@~-=¢~@ uoom o.om Nfi m~.~ mm.o mw.w ~.w mpemufia wnewufle o.om - m¢.~ o m~.@ ~.~H mpewofiw + @-m.¢.~ mnewufiw + P-m.<.~ ¢.¢m QH mm.“ c @~.@ o.m~ @-m.¢.~ P-m.¢.~ m.m~ 1» -1 1| 1| || mpcosumonuonmv wcoz cofipusuonm :o>o 2o~w ammo ucoapmonw “moo CHDHQH oucmcowcfimz ~m~»H:H wflwu xmmnn um: ~m::=m mo ucoewmonw mo mum» Jucosumonh . . wmcmoz op wcwspmmwh cofipuswon ~mwuwG~ ~m:c:< » m~mo> pmou wwwmscwm £0 ~ £GHHG> UMEOGOUQ m .wmm~ .nmu~whmoom :0 comm; .mr:mH~onE@;.mmxmH pmmm co @¢@~@@ w:@c:m~Q ~@@>-@~ m ao>o ~mnm-on wnmfiv mwuwnn o-~mu uzu\v¢w cam cofipusmoam m~mo|2ou co woman mo>@~m:nouHm ~on~:oo owfisvmme >@=¢= wouumflmm EOHw -mm>\@aum\n~V cofipuswonm mfimu vocmoz flmwou ncm .xuouwo>@~ new fionucou swans cfi w:oEawo>:@ ~m@pHc@ ao>ouon op wonfisvop mumox .~wnum\wV zofiw smmo pm: ~m:=cm nmmmonocfi .:nsuo» we mums ~m:=:m wm m wflofix op uonfizvou ~onom\wv mwwou ucwewmmnu Mmfiwflcfi c@ cofiwosuon .~osum\wv mwmoo ucoswmonw ~m@~@=@ .~wv canvas mo moans ~m::=< .m¢ ofinmh LI Tin the region (Table 3). 118 Alternative Adjustment factor 2,4,5-T A I 0.70 2,4,5-T + dicamba 0.66 Dicamba 0.63 Root plow=rake—Bermudagrass 0.28 Rio Grande Plain The Rio Grande Plain (South Texas Plain ) occupies 20.5 million acres of nearly level to rolling brushy plain, more than 72 percent of which is used primarily as range (Table l). Elevation ranges from.sea level to 1,000 feet, annual rainfall is 18 to 30 inches, and the annual frost-free period is 260 to 340 days. Upland soils are dark, calcareous to neutral clayey soils over finn clayey subsoils. The bottcnllands are typified by brown to gray, calcare- ous silt loams to clayey, alluvial soils (Godfrey, Carter and McKee Uhdated). The Rio Grande Plain contain$l5.3 percent of the beef cows in Texas and 9.3 percent of the ranch firns. Of significance is that 60 percent of the cows are located in herds of 200 cows or more with nearly 40 percent of the cows in the regions being located in herds of 500 or more. These cow herds are owned by 12 percent of the total ranch firms This indicates that brush control may be relatively less subject to cash flow constraints compared to other regions. The south Texas mixed brush complex has been described in detail by Scifres (l979a). Although mesquite is a dominant of most mixed brush stands, this analysis was concentrated on rangeland where mesquite is the G 119 primary problem; that is, occuring in essentially p1.m:e stands. The uplands on the Rio Grande Plain are dominated by thorny mixed brush of which honey mesquite is usually a maj or species. Understory vegetation is generally typified by short and midgrasses and diverse populations of forbs. Bottomlands support heavy stands of honey mesquite and other brush and hardwoods. It is estimated that honey mesquite is a management problem on over 85 percent of the Rio Grande Plain rangeland (Table l). Although almost half of this infestation is considered to be "light" because honey mesquite is only a part of the mixed-brush complex, about half of the infestation is represented by moderate to dense canopy covers. The most severe infestations occur primarily on highly productive sites with only the shallow, rocky ridges being essentially free of mesquite. Severity of the brush problem is indicated by common reference to the Rio Grande Plain as the "brush country" of Texas. According to Hoffman (1978), from 1973 through 1977, an average of 55,380 acres were treated annually with herbicides, and 214,190 acres were treated annually with mechanical brush control methods. h Only "deep range sites were evaluated in this evaluation of the Rio Grande Plain, Annual rates of reuirn, based on applications of 2,4,5-T for honey mesquite control on the more productive sites of the Rio Grande Plain; were 8.1 to 21.8 percent (Table 46). These high rates of return are indicative of the production potential of deep soils in South Texas. Much of the Rio Grande Plain has the capability of producing agronotnic crops and vegetables, limited only by a ready supply of water of accept- able quality. In contrast to 2,4,5—T, annual rates of return from dicamba ranged from 2.9 to 16.6 percent. 120 r A1 .wwHuomm mowmmnm we oaspxfie o>@~mz u .onom\n~ m.oum @@H~@@@ mm: zuwsz EwhO~0HQ + &|m.w.~ pmmoxo wnom\n~ ~o.c um @@-@@@ »-m~pom mowfiufinnmz Q .>-m:vo mchzwow wcm wpmou wuomwm fififlz cofiumflmcfi mwE:mmm;wmouonm mfich .mm»mn ~mon mcw ow wwmn coflumfiwcfi woesmmm cm mcfinwm >@ wane on xme cpzpop mo mmuma ~mc~Eoc we woxnms mo oumefipmm =< .:n:p@n mo mmumh ~moa wwawwfimcou QHQ new muummefi :o@~w~w:@ ov:~u:H woe ow cusumn we magma flmsccm .w:cH .m»m~Hon wnmfi wcmpmcou ca wmwumhonm oaoz mcaswoa ucm mpmou .¥uopm |@>@~ mcwwouan wcm flouwcoo swans cfi Hmwflmmu ~:mE~mo>:H wcm wcflumnomo flfim mwoufiwcoo cnspon mo wwmw oak m @~@@@N >Q@-H= wmfiflou mwww >u@HH@= m@~@~=¢u mowucsou _@u@@>~ || 1|. 1| >.m || || mans wmm»w~owm:n»oxmp|zo~Q poem || 1| o.v 1| »| 1| nsnu mw:Enmm|mxma|2o~m poem || 1| |¢ ~.m ~.m || Emao~u@m + P|m.v.~ u1oom|3o~Q uoom m.m o.o || -| 1| || Emno~u@m + h|m.v.~ un@mm|3o~Q uoou|:~m:u ,|| -1 >.@ I- || -1 uwnnw woasm ~.N m.m ~.- ~.@ “.w m.m Emno~u@m + »-m.¢.~ Em~o~u@@ + ~-m.<.~ @.~ m.m @.o~ ~.¢ m.o @.w mpemufim mnsmuwa @.@ @.M~ w.¢~ w.w @.¢~ @.- mnemufin + P-m.¢.~ @@e@U@v + @-m.<.~ ~.w ¢.m~ w.- m.¢~ ~.- @.- F-m.¢.~ +-m.¢.~ fi¢¢v ~m~v ~@_V HNMV m-v Amfiv @Q=@=@~=M@: ~m@p@:H 35m ofiwhwnoz Evewmmh» ~@»\=<\w»Qu~v Q xuwummmu mcwxuumu ~m~u~=@ mam uo>ou xmocmu » .w~¢_ .m@xQ» ~=m@_¢ o@=@»¢ oflm us» co nowaom @=~==@_¢ pnoxlow n »o>o ~m~n-on wwafiv mouflpm o-~mu ~:u\wwm new mzowpmhomo m~mu|2ou co wuwmn mouwm moan =0 mo>M~m:nou~m ~onu=ou oufiscmoe xocoz wo~uo~om Eouw Awv cannon mo wows» ~m:::@pmz u wwfifimmm mm: ;uH=: Emnofiuwm + @-m.<.~ wmooxm onom\n~ >o.o um voH~mmm >-m@nom mowfiufinnor n .m»=osuwm>c@ xuoumo>@~ mcwwooan woman onsflucfi Ho: ow mpwou ucosumopu fimfiwficfi . . m uuo: mwmmmm @w@~@w Efiw >umH~@2 wo~mN=ou mofiwcsou _@u~@>@ || -1 oo.ow 1| || nsnu mmmaw~omw:c|@xm»|2o~m poem || oo.oo~ 1| || 1| nsnu mmmnmmw:Enom|oxma|3o~m poem -1 »| oo.mm oo.mm || Emnofiufim + F|m.v.~ uwoow'2o~n poom oo.mo 1- -1 || 1| Emuofiufim + H|m.w.~ uuoomlzofim »oo~-:Mm:u || oo.o +1 || -1 woncm . uo~:m, 8E $3 £2 GS 3.: Réwawpfimz 33:: . oumuouoz ~cmE~m@~e¢<= ~@>\=<\m@go@v Q xuwummmu mcflxuamu flmflpficw vcm uo>ou xmocmu m.m~a~ .nmxoh .w:@m~; owcmaw owz oz» co woufim moon co mm>@uw:aou~m ~onu:ou owwscmos xmcoz wouuofiom now ~onum\wv mwmou ucoepmonw ~w-@:~ .~v ofinme 124 ._ U. i .mo@oomm.w@um@wQ mo maswxws o>Hwmz J .wnom\nHm.o um w@@~mmm mm: sufisz Emao~oMm + h1m.¢.N umouxoJ@aum\n~,hQ;Q~m woH~mmm >-QH»om wonfiuflnpmz n .mwm:o@xo.:o@pQ~wmo new mfimawcm mcfiwwonn wommo~o=@ .~onp=ou swans cfi w@~ww>c@ ~QpHmmu vwnwm -Q mom ompwzu wmmaowcfi wm Q mmsammm @:~m> wcwmunm pm: wca Q mummmw >um-H2 wmfifiou wQm% >um-~z mo~m~:oo mowpczou ~mu@mx& 11 11 11 mm.ow 11 11 nsnw mmmnw~omw:n1wxma12o~mwoom 11 11 ~w.Ho 11 . 11 11 capo mmwawmw:s~mm1o¥m~12o~mpoem 1- 1- 11 @N.m~ ~Q.Q~ 1- EmHO~ow@ 1 P-m.¢.~ UQ@@m-=¢_Q poem ~m.mm co.vv 11 11 11 11 Emno~u@m + h1m.<.~ uwomm12o~m ~oou1=@m:u 11 11 ¢w.Q 11 11 11 ,w@~:w uwpzm oN.@ o o -.N Qm.Q o smpofiufim + P1m.<.~ Emnoflufin + P1m.v.~ QQ.Q Q Q . 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AQQV owwmw V fiwfiv wmmv www%m%o2 ~m- @Q=@=@~=@@z nucoewmonk ~m@p@:~ A§\=€m?83 xyfiummmu m=@>-¢U Mmfipficfi wax no>ou xmocmu |||IIll)fI\ .@~@~ .m~x@@ ~:@m~@ vocwnu ofim osw co vofiaom w=H::m~m amo>1om m no>o ~m»m-ow w>m~v.mou@am @-~@u u2o\vvw mam mcofiumnomo m~mu|2oo co woman mopfim moon so m0>aumGH0u~m opfizwmoe >@=¢= nowuvfiww EOHM Aoauw\»v 3o~m ammo um: fimsamm wommonoc~ .mw ofinmk Iv 126 an .wo@uomm woummnm we mnspxfis o>@wmz u .oaum\n~mw;uum wofiflmmm mm: sows: Emao~u@m + H|m.w.N umooxo o»um\n~ Egvwm wo-mmm >-m@nmm wonwofinnoz n .pc@euwm>:@ osu uo>oumu on wonwdvua on -H3 mnmox om cmsu noumoam mmwmofiwcfi + om < :.xumn|>mm: mo mafia wzu an cofiumnomo ocw ow mcusuon mmonm pcomoamoa nfisoz wan .vo@aoQ ~:o|>m@ ms» mo upmm mm w@w:~ucH poc wwm ~o~nmu@~mmm mfiv ~o-=ou swaps new mzou mo wo:~m> omm>~mm .mo@~@::~nommo u:oEpwo>:H owm:~w>m op wow: xflcoesoo =@o@~@@ xumnlxmmz m mwcwmoamon vowuvm osfiu oak .wow:~u:@ mam wmmnmso uwoaoucfl 0: mam wo~@~@~: mm: co~@noc w=@==m~@ ~@@>-¢N < m mm mwmmmm >om-Hz wm-ou Em% >um-@: mmfiwucou mofiucsou ~mu@m»P »| 11 || m~ |» 1| nsnw wmmaw~oww:n|oxm~|2o~muoom -| || NH || || »| nsaw mmwammwzeuomlmxmalzoflmpoem || 1- || v~ wfi || Emuo~u@m + P|m.w.~ Qw@um-:¢~@ uoom wfi + ow || || || 1| emnofiuflm + h-m.¢.~ uwomm»:o~m poop»:~m;u || |» m~ |' || 1| nonsw nwnzm S 2 Q 2 2 S EmSUE + fiméJ 592.38 + Wméa w~ w~ . w >~ o~ - mnemuwa mnemufia mfl m m mfl m ofi mnsmoww + F-m.¢.~ mnemufiw + P-m.v.~ 3 w m 2 m 2 ._...m.v.~ Plmiiw o Amwv ~w~v Ammv Awwv Amfiv oucmcopcwmz ~m@~@c~ A qv omcoc uwmuwwoz npcuewmwnk ~n»\:<\monomu xuwuwmau ucwxuumu -@»w=~ ucm no>ou »@¢=@u m.w>m_ .mmxoP _w@m~m wwcmwu oflm ozu no ~m~m-ow w~m~v.wou@nQ ogpumu u2u\w¢w wcm :o@wu:uonm wHmo|2oo m co woman xuo»wo>@~ wcm mowflm mwwn co mo>Auw¢hou~m ~o»~cou wwwsvmoe xococ oouuo~mm cw ~=oEpwo>c~ ~m@-c~ ao>oum~ ow @@~@=¢@~ mane» .om ofinmk 127 investment in treatments involving mechanical treaunents on the Rio Grande Plain. Root plowing and other mechanical methods are commonly used for brush management on the Rio Grande Plain. During the past 5 years, about four times more rangeland was treated mechanically than with herbicides. One reason for the greater use of mechanical methods is that conventional herbicides are generally only partially effective for control of many of the woody species associated with mesquite in the mixed brush complex (Scifres 1979b). Averaged across the situations evaluated, pretreatment annual calf production averaged 13.8 pounds per acre (Table 51). Following treatment with 2,4,5-T, it was estimated that the rangeland would produce an average 20.9 pounds per acre annually of beef representing a 51 percent increase in production. In contrast, root plowing-seeding treatments increased pro- duction by an average of 116 percent on applicable sites. Annual productivity was higher on tane pastures ranging frow»43.8 to 76.9 pounds per acre for buffelgrass and coastal Bermudagrass, respectively.‘ These livestock production estimates indicate the relatively high production potential for the region Coast . Prairie- The Coast Prairie represents about 9.5 million acres of nearly H level plain in the extreme southeastern portion of Texas (Figure 1). Elevation ranges from sea level to 250 feet,and annual rainfall is from 28 to 56 inches. Soils are dark, neutral to slightly acid clay loans and clays in the northern portion and light, acid sands and darker loamy to clayew'soils in the southern portion (Coastal Bend) (Godfrey, Carter and McKee undated). Higher rainfall, an annual frost-free period of 240 to 128 .maum\n~m;ou& uofiflmmm mm: sows: Emno~u@Q + P4m.w~N umwuxo onum\nH~@.oum nmwflmmm >~Hm@awm mowfiuwnpoz. .mofiuomm woummwm we oaswxwé o>@pmz u n .womcommun cofiwoswonm @m@»@>@ asp QCMEHQHQQ ow woNM~@~: mm: wo@n@m mcficcmflm ~¢@>-¢~ < m mwwmmw >u@-Hz umflfiou u%%% >um-@2 mo~mN=ou mofiuczou _@U@@>@ || »| || w.m¢ || 1| nsnu mmm»wHoww:n'@xm~|2oHmpoem 1| 1| m.o~ || '1 1| nswu mmmnmmw:Emom»oxmn|3o~mwooz -- -- -- m.m~ ~.w~ -- E¢»o_U@@ + P-m.¢.~ u@@@m-3o_@ “cox @.- ¢.- -- -- -- -- Emhafiufim + H-m.¢.~ Q@@@w-:¢~@ ~Qo~-=@m;u || || ~.- 1» || 1| wonzm umusm @.- ~.@H m.¢m m.m~ ~.- ¢.@~ Ewpaflufig + P-m.v.~ Em~o~u@m + P-m.¢.~ Nuwfi @.w~ ¢.@~ ¢.m~ m.~N o.m~ mnemuwo mnsmufla ~.- @.@H v.m~ ¢.mH m.HN Q.@~ mpemuflw + ~-m.<.~ wnsmufin + @-m.Q.~ N.- @.w~ ¢.@N ¢.m~ m.~N ¢.¢~ P|m.w.~ h|m.v.~ ~.w w.- @.- H.¢~ w.<~ ~.@~ -=@e~@@-@~@V @=oz 83 $3 SC S3 3S $2 Qufiwcfifiwz 123E omcoa . . opmpowoz HCQEHQQPP ~ax\:<\muaomv Q xpwummmu w=@>nnmu ~m@»@:@ wcm no>ou xmocmu .waxov =@m~@ owcmuw omm uzw :0 mo~@n moww co mo>@uw=Hou~m fionucoo owwscwoe xocoz wowuo~om scam ~ Q »mo>\onum\n~v cowuuswonm w~mo vocmoz ~m~oP .~m ofinmk 129 320 days, and productive soils lend high agricultural productivity to many areas of this resource area. Native vegetation of the uplands on the Coastal Prairie are typified by live oak savannah and honey mesquite-dominated mixed brush with mid- to tall grasses in the herbaceous layer. Nearly 2 million acres, about 2O percent of the land resource, is used as range (Table l). Pure stands of honey mesquite are rare and, mesquite generally is not a serious problem for the region. Mesquite occurs primarily as a component of "chaparral," a mixed, thorny brush complex often composed of l0 or more woody species. It also reinvades rangeland rapidly following application of brush manage- ment methods. Therefore, most of the mesquite infestation is classified as light to moderate infestation. Although Hoffman (1978) estimated that about 21,000 acres- were treated annually with herbicides from l973 through 1977 on the Coast Prairie, aerial application of herbicides on much of the land resource is seriously constrained by the intensive use of the areas for row-crop agriculture (Scifres l979b). Therefore, treatments such as oiling and mechanical methods often are used. For example, mechanical methods were applied to about 47,000 acres annually from 1973 to l977 on the Coast Prairie (Hoffman l978). Moreover, the high rainfall and fertile soils of the area lend considerable flexibility in the choice between tame pasture g conversion and improvement of the rangeland. However, annual rates of return for the treatment alternatives evaluated in this study were surprisingly low (Table 52). Highest annual rates of return, 4 to 6.5 percent, were generated by oiling. The low armual rates of return were attributed largely to the high initial treatment cost, from 30.00 to 130 ~m~V wmcoa -~v wwmnwwoz fimflv omcoa Away oumaowoz ~m~v mmcoo hmflv opmawwoz ~m_v wwcoa Awfiv owmaowoz A~>\=< 11 ~.@¢ ~.@m 1| ~.~m ~.@~ ~.<¢ ¢.@¢ || .m.mm ¢.~m o.v~ :~amm>\onum\n~v coflwuswonm w~mu wocmoz flmwoh |1 + ow + ¢~ || mfi 1| + ow + ow + om .|| + ow mfi |1 mp:oEpwo>c@ no>ouoa ow @@~M=¢@~ mnmw> || ~m.~ mw.H| || mo.~ || m~.~ >m.o 1| mH.¢ @@.H || m~@aom\wv zofim ammo pm: ~m:=cm wwmmm~u:~ || @@.~¢~ |¢m.@w 1| @¢.m~ || wo.~w ¢w.- 1| @m.>m m@.> || ofimnom\wV mwmou ~m@~M:H 2“ cofiuusnon wmnfisvom 1| ¢¢.¢anmu,~m@~@:@ |2o~ uoom 12o~ uooz mmucosumoaw ou:w:u~:~mE\~m@»@=@v o>Hum:no»~w ~on~:ou opfiswmwa >@=¢= can ao>ou >@¢=@@ .o~uMmam m.w~m~ .mmxmP ummou oz» co mo>@~m=aou~m fionucou Qwfisamoe >@=¢= vouum~om ow mowcommoa cofiuuswonm wan ufieoccum .~m o~nmP J31 .co@am@ wc@=:m~Q nmo>|o~ m co woman mowcommma cofiuuswonm @w@»@>< .p:oEumo>c@ map no>ouoa ow wonfiswmn wnnox ow can» nogmoaw mwumufiwcfl + ow < =.¥@m@¢»@@= mo oeflp ocu Hm cofiumnomo wcu ow mcnspoa mwonm ucomonmoa w~:o2 pan .@¢fi~@@ u:o|>mm on» mo unmm m mm wow:~u=@ pom mam flofinmofiflmmm wfiv Hoaycoo swaps new mzou mo mo:~m> omm>~mm .mm@u@::»aommo ~=oE~mo>c@ @~m:~m>o ow wvm: xflcoseoo woflaom zxumnrxmmz mpcmwoanum .wow:Hu=M momamnu pmwaoucfl psospfis wofiaom w=fl==@~@ nmo>|o~ m co nmmmm A V .mopowHm=ou woe mm: mzoflw ammo mo mcfisfiu osw w:m.woc:Ho:@ woc mama mownmsu ~monop:H .wo@nom mcwccmflm nmo>|o~ osp mo mam ms» pm ofinmofifimmm mflv fioawcou swans cam mzou mo o:~m> omm>~mm oz» mafia mpmou wcwwmaomo ~ms:=w wommonucw can .xuo~m@>@~ wcfiwmoan wowwm .~oau:ou swans mo mpwou wwofi wczom mom amflflow ¢v.o um mofimw ammo wmwwm ~muo~ mfi 2o~m ammo we: use .momcomxo cofiumnomo wan .m~mE@:m m:@voman_©ommmnu:@ ~aOH%COU £W5HD Cw UOHm®>Cfi MMHMQQU -m HOW QMHMJU Hm®HOHC@ NQ G mofismmm o:~m> HCUMOHQIHQC ®£P .mucoEumo>¢@ xooumo>@~ MGMUQOHS UQUUQ QUDMUCM HOG Ofi muwoo HGOEHMOHH MMMHMCM .>H~m:¢m mcaspoa wcm mpwou uuommm fifiwz :o@pm~m:@ wasp moanmmm mmooonm m sosm .no>ozo: mmopmn fimon oz» ow ouma :o@wm~m=@ wossmmm cm wcfimmm >@ woumewumm on xma cnswoa mo moumn Hmcfieoc no uvxnmz .cn:uoa womopmn ~mon wonmufimcoo mam mam wwummefi cofipmflwcfl omnfiocw won ow canvas mo mouma ~m::cm .m::P .mnm-on w>m~ ucmumcou cw wouuo@onm mcnsuma ucw mumou .xoowww>@~ w=@@@@~@ mam fionucoo swans cfl ~mu@@mu ~=oE~mo>c@ can wc@umnomo‘-m wnonfimcou . .moHuomm vmummwm mo oasuxfis o>@~mz .GMHOHUM> MM %HC5OU afiOMQ%P ;b .wo::@ucou .~m wfinmk 132 150.00 dollars per acre for the alternatives evaluated. Therefore, reductions in.initial treatment costs to achieve a 9 percent annual rate of retun ranged from 7.65 to l02.6l dollars per acre. It would be expected that unless livestock prices are maintained at a relatively high level, increasing energy costs will continually erode profitability of present brush.nanagement practices for the Coast Prairie. Increased anual net cash flows from the brush management alternatives evaluated ranged from.—l.85 to 4.26 dollars per acre. Oiling required from 13 to l5 years to pay back the original investment, and the payback period for all mechanical practices exceeded the 20-year planning horizon. Factors for adjusting annual rates of return, asvdiscussed for the High Plains, when cattle prices ranged from 34 to 54 cents per pound, are: Alternative Adjustment factor Oil 0.39 Tree doze (oil as maintenance) 0.23 Tree doze (shred as maintenance) 0.23 Boot plowerake-seed natives 0.24 Root plow—rake-kleingrass 0,26 Root plowerake-Bermudagrass 0,29 _§dwards Plateau The Edwards Plateau covers about 24 million acres (Godfrey, Carter and M¢Kée undated) Of WhiCh 93 percent is rangeland (Table l). The land is deeply dissected, covered with brush and the area is often referred to as the "Hill Country." Elevation is 1,200 to 3,000 feet, annual rain- fall is l2 to 32 inches and the annual frost-free period is 220 to 260 days. 133 Upland soils are dark, calcareous clays and clay loams which are shallow with frequent rocky outcrops. Vegetation is dominated by live oak, shinnery oak, junipers and honey mesquite. The area becomes desert shrub on the western edge as it joins the Trans~Pecos. Oak and pecan are connon on the bottomdands, especially in the eastern portion of the resource area. vThe Edwards Plateau region (including the Central Basin) has approximately 6.8 percent of the cows in the state but is the major location of the sheep and goat industry in the state (Table 3). Sixty-two percent of the cows in the region are in herds of 200 cows or fewer which represents 90 percent of the ranch firms of the region (Table 3). It is significant to note that Table 3 represents cows only, and the relative proportions of larger herd sizes based on animal units could be expected to be higher than reported.‘ Honey mesquite infests almost 60 percent of the'rangeland on the Edwards Plateau CTable 1). Howevery 48 percent of the infestation is of lightcanopy cover and occurs primarily in mixture with other woody species. Mesquite stands of moderate to dense canopy covers are confined primarily to the deep range sites. According to Hoffman (1978), from 1973 through 1978 there was an average of 144,200 acres annually treated with herbicides for brush control on the Edwards Plateau, During that same time period, 130,050 acres per year were treated with mechanical methods. The Edwards Plateau varies so widely in environmental and edaphic Jconditions that it could be evaluated as several sub-regions. However, for purposes of this report, it may be adequate to emphasize only that the western part of the Edwards Plateau is essentially the same as the 134 Trans—Pecos, the southern part grades into the Rio Grande Plain. and the northern portion into the Rolling Plains. Therefore, site potential varies wide1y;with initial (pretreatment) carrying capacities on the deep sites ranging fron1l8 to 20 acres per animal unit per year in the eastern part of the region to 120 to 159 acres per animal unit yearlong in J the western portion. ' On shallow sites with dense canopy covers of honey mesquite, aerial application of 2,4,5-T ranged from 7.3 to 23.2 percent annual rate of return (Table 53). In comparison, annual rates of return for moderate“ canopy cover on shallow sites‘ranged from 4.3 to 16.6 percent. Thus, the economictpotential of any given treatment varies widely with site condition on the Edwards Plateau. However, averaging across sites allows a direct comparison among herbicides. Average annual rates of return were 11.9 percent for aerial applications of 2,4,5—T, 10.8 percent for 2,4,5-T + dicamba, 7.7 percent for 2,4,5-T + piclorwn and 7.9 percent for dicamba. Annual rates of return for mechanical practices ranged from -1.4 to 5.2 percent (Table 53). The highest annual rates of return were generated by seeding projects which included raking following the initial land preparation of range sites with high production potential. Within a canopy cover situation, rates of retun were uiformily higher on deep than on shallow sites (Table 54). Averaged across moderate canopy cover situations on deep soils, average annual rate of return for aerial application of 2,4,5-T was 12.8 percent compared to 10.3 percent on shallow \ soils, 11.8 percent for 2,4,5-T + dicamba compared to an average 9.2 percent on shallow soils, 8.7 percent for dicamba compared to 6.0 percent 135 .mm@uomm woummwm mo oasuxfis o>@~mz u .oaum\n~ m.o um wo@~mmm >-mH~om mowfiufinaor .>-m:wm mcnspon wcm mpmoo wuowmm -~2 cowpmflwcfi moesmmm mmmuopm mH£F wcfiwwm >@ owns an >@§ caspoa mo mowma flmcfisoc no uoxnme mo owmsfiumo :< muummsfi coflpmfiwcw on:~o:@ woc ow casuos mo moan» ~m:=:m .m:cH n .mowma ~mon OZH OH QHQH :¢@um~m:@ nmenwmm GM .CHDHOH MO WOPQQ afibfl nugonfiwcoo mam UCQ .mH@-OU whmw HCQHMCOU Cw ©®HU®mOHQ QHQ3 mcaswon mcm mumou . xuo~m@>@~ wcfinmonn ncm flonwcou zmsan cfl ~m-@mu p:@Epmo>:@ wan wcfiumnomo fifim mnon@w:ou CMDHQM we wpmp oak m no~>mH mfigefix wanna: @=@~@@: aocoflwfisum namcoz mmwucsou flmuwnxh 1| ~.~ 1| || m.~ 1| nsuo uvoom|mo:o no-on|3o~m uoom <.~| || 1| v.o| 1| ~.m nznu uwoom|oxmn|3o~m uoom ~.~| Q.< 1| N.c m.~ w.w nsno uwoom1oxma|oNow omah || 1| 1| w.o 1| 1| nznu uuoom|o~ou omuh 11 11 o.~ 1| || 1| nano w~ow ovuh Né we Tm: ma- N6 9S EESUE + Tfliw 5.2.633 1 Wméa ~.m 0.“ w.§~ o >.m v.- mnemuwo mnsmufin vs 2w Q8 N6 Qw 92 @3583 1 ._.|m.<.~ .353? + @-m....~ m.“ ~.o~ ~.m~. m.w ~.¢~ @.@H P|m.<.~ @|m.¢.~ S8 $3 SS Q3 82 G8 wuswafifimz 83:: mwcoo opmumwoz »:@s~moah1a| ~QQ=ou xmocmu .w~@~ .mmxoP .:@@-~@ Q wwnmznm ocu co nofiaom w=@==@H@ nmo>1o~ m no>o mmnm-ow wwmfiv moufiam o~uumu u3u\vww wcm cowwoswonm w~mu|3ou CO momma mflfiom ZOMMGSW CO mo>~umcnmu~m HOHHCOU QUMDUWOE %®CO£ UOHUQMQW W0 aww CHUHOH QQ WQHQH afi3CC< . II ll .mm Qfinme 136 .m0@uomm cowmmnm we oaswxfie o>@umz 0 .oaum\n~ m.o um wo@~mmm >-m~nmw mmwfiuflnnwz A .>-m:¢0 mcnsuon was mwwoo HUQMMQ -w3 :o@um~m=@ mofismmm mmouonm mflsk .mowmh ~m0n 0£w OH own» cowumfiwcw woismmm cm wflwfiflm >9 Qfimi on AME casuwu MO moans ~mG@EOG no HQMHQE MO mwmeflumw C< .CH5u0H W0 mwumn ~m®h U®H®©@mCOU mam was muummefi =o@»m%w:@ ousfiucfi Ho: on cuswmn we mopwn ~m:ccm .m::P .mnm-oww>m~ ucmwwcou cw wowuwhonm QHQB wcwswon wcm mwmou .zuo~mo>@~ MCMUQQHQ wcm ~OHHGO0 zmnan Cw ~mwHQmo u:mEuwm>:@ UCM MCMHQMQQO -m msmoflmcoo GHDMQH MO owmw ®£P m moowm @=¢~@@z ~¢~>m@ ¢=U=ou Hmgmzmhm @~m=¢= Qfipaflx ~¢@¢ . m@@~==QQ H~U@@>@ >.o o.~ || -| m.o 1| o.m -1 nswo unoomlmozu ao-o»|2o~Q uoom '1 ¢.~ I ~.m || o.o| ¢.m 1| nsuu uvmom|oxmu|2o~m uoom -- -- Q -- -- -- @.¢ -- n=~u Q@@@m-:o~@ ~¢Q= 1| 1» 1| m.o || 1| || m.“ nsuu 2o~m woom 1| -1 ~.~| ~.w || o o.m -1 nsnu owoom|oxmn»o~ow owah H.H -- -- ~.m -- -- . -- ~.m @=~w Q@@@m-@~¢@ Qwhp ~.~ -- -- -- m.~ ~.~ -- -- @=~u @~¢@ @@~P -- -- -- ¢.¢ -- <.m- @.¢~ -- fiwo _@o -- -- -- -- -- -- w.m -- @@~=w vwhgw ll m.© || || II || In I1 P|m~Q~N Cwm£U|P|m.v.N 1| 1| || m.o =| »| -1 || P|m.v.~ wmm»m:@m~x|oxma|o~om omph @.¢ @.¢ -- -- -- -- -- -- @-m.¢.~ ew~o~u@@ + @-m.¢.~ -- -- ¢.Q @.¢~ ~.¢ ¢.¢- >.@~ @.HN e@~¢~u@@ + @-m.¢.~ E-¢_Q@@ + +-m.¢.~ ~.¢ ~.@- w.~ ~.¢~ ~.m @.m- ~.@ m.¢~ ~@Emu%Q mnewufig @.@ @.m- ~.< m.m~ @.@ w.¢- @.- ~.¢~ mpsmufiw + @-m.¢.~ wpamufiw + +-m.¢.~ Q.“ ¢.m- ~.m @.¢~ @.> ~.¢ w.~H m.m~ P-m.¢.~ @-m.<.~ A¢m_v Aomv fi~¢. .m~v ~¢~_v Ammv fivwv ABHV @U¢¢=@~=@@z ~@@~@=_ omcoa QHQHQQOE HCQEHQQPP ~a>\:<\woauwM n >u@umamu ucwxnumu ~m@p@=~ was ao>ou xmocmu .w~@~ .mmx@P .:mo~m~m vnwzum ozu co uofinom w=@==@~@ umo>»o~ m »o>o Awamflfiou w~m~v moufipm o-~mu ~2u\wvw wcm cofiuusmoan w~mo»2ou CO QOWGD m-ow QQQU CO wu>@um=awu~m MOHHGOU 0HwSUmQE %0CO£ UQHUQHQW MO a&w CMSHQH %O WQHGH mQ3CC< .vm ®~D®P 137 on shallow soils, and 9.3 percent for 2,4,5-T + picloram compared to 6.6 percent on shallow soils. The highest annual rate of return from mechanical practices applied tg deep soils was 7.9 percent for root plowing of the site with highest produc- tion potential (Table 54). Establishment of kleingrass generated a 6.9 percent annual rate of return for the single situatio for which it was evaluated. In contrast to other vegetation regions, oiling generated a 10.6 percent annual rate of return in one case on the Edwards Plateau. However, it resulted in a -3.4 percent rate of return on a site of lower production potential. To estimate annual rates of return of the selected honey mesquite alternatives within the range of prices, 34 to 54 cents per pound, the following adjustment factors, as discussed for the High Plains, are presented: Alternative Adjustment factor 2,4,5-T 0.57 2,4,5-T-+ dicamba . 0.56 Dicamba 0.50 2,4,5—T + picloram. 0.52 -2 ,4,5-T + picloram (2,4,5-T as followup) . 0.37 Tree doze-rake-kleingrass 0.48 2,4, S-T-chain l 0.37 Shred 0.51 Oil l 0.30 Tree doze 0.24 Tree doze-seed 0.21 Tree doze-rake-seed 0.20 Root plow 0.28 138 Root plow-seed ' 0.20 Root plow+rake—seed 0.19 Root plow~roller chop-seed 0.20 Cbsts of herbicide treatments on the Edwards Plateau were the same as for the High Plains ("Table s). Costs for mechanical practices varied with the specific mesquite canopy cover/site potential situation Clables 55 and 56). For the 14 situations evaluated, a cost reduction was required for seven of the cases if a 9 percent annual rate of return was to be generated from aerial application of 2,4,5-T (Tables 57 and 58). These cost reduction requirenemts ranged frm.0§35 to 5.00 dollars per acre, from l5 to 91 percent of the original treatment cost. _A cost reduction was required for 2,4,5-T + dicanba in eight of the 14 honey mesquite control situations and nine of the situations when dicamba or 2,4,5—T + picloram were used. However, cost reductions were required for all mechanical practices to yield a 9 percent annual rate of return, some requiring reductions of more than 50.00 dollars per acre. Increased annual net cash flow across the 14 range site/mesquite caopy cover situations averaged l.ll dollars per acre for aerial application of 2,4,5-T, with one situation resulting in a negative cash flow (Tables 59 and 60). The overall average increased annual net cash flow for 2,4,5-T + dicamba was 1.05 dollars per acre with negative values for two situations where potential productivity was relatively low. Aerial application of dicamba generated an average annual increase in net Q cash flow of 0.88 dollar per acre with one situation resulting in no increase in net cash flow and two situations being negative. The 139 .mo@uomm nowmmnm mo oaspxwe o>H~mz u ..0hUM\D~ m.O PM ©®w~@QG x-m@hom wowfiufinpoz Q .mu=oEum0>=@ xuoumm>H~ MGMUQQHQ uouwm on:~o=@ HOG Ow mumoo HGQEHGQHH ~mHw@:~ m HO~>mP ®~£E@¥ US$202 wcmfiwwz aocofioflcum QHMCQZ wvfiucsou ~muwQ>F -1 oo.mv || || oo.mv || nsao unomm|@o:u no~Hon-3o~m uoom. 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Average increased annual net cash flow for 2,4,5—T + pic1oram.was 1.18 dollars per acre with negative cash flows resulting from two of the 12 situations. The greatest increase in annual net cash-flow frm.mechanical alternatives, 7.13 dollars per acre, was produced by establishment of tame pastures with kleingrass. Payback periods ranged frn.5 to more than 20 years for aerial appli— cation of 2,4,5-T (average of 12.8 years) (Tables€H.and 62). The shortest payback periods occurred when the herbicide was applied to the sites with highest production potential (initial carrying capacity of 17 to 22 acres per animal unit). With the situations of greatest production potential, payback for aerial application of 2,4,5-T-+ dicamba or dicamba also required 5 years. Payback periods for mechanical methods ranged from 12 or more than 20 years. Total annual weaned calf production, averaged across all situations, was 9.8 pounds per acre before treatment whereas it averaged 15.6 pounds per acre following aerial application of 2,4,5-T, 2,4,5-T-+ dicamba or dicamba (Tables 63 and 64). Based on twelve situations involving aerial application of 2,4,5—T + picloram, annual average weaned calf production was 17.9 pounds per acre. However, annual average weaned calf production ranged from 7.5 pounds per acre to 30.6 pounds per acre following spraying, depending on range site potential, initial mesquite canopy cover, and herbicide(s) applied. Annual total weaned calf production, averaged across all situations using mechanical treatnnnts increased from 9.8 pounds per acre to 21.1 pounds per acre. 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Elevation is l,000 to l,800 feet, anual rainfall is 25 to 30 inches and the annual frost—free period is 220 to 230 days. J The upland soils are reddish brown to brown, neutral to slightly acid“ and most are gravelly and stony, shallow sandy lOamS over granite. Bottom- lands are dark gray, neutral to calcareous alluvial soils which support hardwoods. Upland vegetation is dominated by honey mesquite, live oak, post oak and sodgrasses to tall grasses. Honey mesquite is a management Problem On ab0uI 97@percent of the rangeland in the Central Basin and occurs primarily on the range sites of relatively high production potential (Table 13- Characteristics of ranch firm: are discribed as part of the . Edwards Plateau discussion. l Average annual rates of return for aerial applications of 2,4,5-T, based on two production situations, was ll.l percent (Table 65). Average annual rate of return from aerial applications of 2,4,5-T + dicamba was l0 percent, 6.9 percent from dicamba only, and 6.1 percent from 2,4,5-T + picloram. Mechanical practices resulted in 0.7 to 2.7 percent annual rates of return, based on cattle prices of 44 cents per pound. To estimate annual rates of return for other than 44 cents per pound, as discussed for the High Plains, the following adjustment factors may be used for cattle prices ranging from 34 to 54 cents per pound: 151 Table 65. Annual rates of return (%) from selected honey mesquite control on two canopy cover situations on deep sites based on cow-calf productign and $44/cwt cattle prices (1978 dollars) on the Central Basin, Texas, 1978. Canopy cover and initial __ Carrzszérsizacig ‘as::::“"”r> Initial . Maintenance __f§6Y“_ Tiff" 34-5” 2.4.5-T 8.1 14.1 HMS-T (B) 2,4,5-T. (a) -0.2 4.2 2,4,5-T + dicamba 2,4,5-T + digamba 7.0 13.0 Dicwbn Dicamba ‘ 3.8 9.9 3-454 * Pi¢1°T8m 2,4,S-T + piclgram 4.7 7.5 Tree doze—seedc Grub Q_7 2_7 Root plow-rake—seedc Grub 1,7 2,7 Typical county ~ Llano Llano 3» v A 20-year planning horizon was utilized to estimate annual production changes. b Herbicide treatments aerially applied at 0.5 lb/acre except 2,4,5-T (B) which indicates basal spray. C Native mixture of adapted species. 152 Alternative Adjustment factor 2,4,5-T " _ 0.60 2,4,5-T(B) 0.33 2,4,5—T~+ dicamba 0.58 Dicamba A 0.52 2,4,5-T + picloram A A 0.43 Tree doze—seed natives 0.22 Root plowerake-seed natives 0.23 Only in.three situations were cost reductions not required for the honey mesquite control alternatives to yield a 9 percent annual rate of return (Table 66). Annual increases in net cash flows ranged from -0.03 to 1.85 dollars per acre (Table 67). Aerial applications of 2,4,5-T required 9 to l5 years for recovery of the investment, and from l0 to 20 years were required for the other broadcast herbicide treatments (Table 68). Mechanical methods required from l9 to more than 20 years to recover the initial investment in treatment. weaned calf production was increased by 36 to 47 percent following aerial appli- cation of herbicides, compared to pretreatment production on brush covered pastures. Highest annual average weaned calf production, 31.8 pounds per acre, represented a 101 percent increase over pretreatment production levels, was produced by root plowing and seeding adapted species (Table 69). 153 Table 66. Initial treatment cost and cost reduction ($/acre) for yielding a 9% annual rate of return on the investment in selected honey mesquite alternatives and added breeding livestock based on cow-calf production and $44/cwt gattle prices (1978 dollars) on deep sites on the Central Basin, Texas, 1978. Canopy cover and initial carrying Initial capacity (acres/AU/yr) Treatmentb. treatment Moderate_ Dense Initial Maintenance cost (20) (22) 2,4,5-T 2,4,5-T 5.50 0.62 0 2,4,5-T (B) 2,4,5-T (B) 20.00 16.16 11.43 2,4,5-T + dicamba 2,4,5-T + dicamba 5.95 1.46 0 Dicamba Dicamba 7.50 4.36 0 2,4,5-T + picloram 2,4,5-T + picloram 9.75 4.01 1.66 Tree doze-seedc Grub 40.00 28.98 24.16 Root plow-rake-seedc . Grub _ 75.00 47.19 43.47 Typical county Llano Llano Llano aThe net present value assumes a 9% interest charge for all added capital invested in brush control and additional breeding animals and operation expenses. Calculations based on a 20-year planning horizon. bflerbicide treatments aerially applied at 0.5 lb/acre except 2,4,5-T (B) which indicates basal spray. c . . . Native mixture of adapted species. 154 Table 67. Increased annual net cash flow ($/acre) resulting from investment in selected honey mesquite control alternatives based on cow calf production alter- natives based on cow-calf production and $44/cwt cattle prices (1978 dollars) over a 20-year planning horizon on deep sites on the Central Basin, Texas, 1978. Canopy cover and initial carrying capacity (acresAAU[y __H _ Treatmentb Moderate Dense Initial Maintenance __T§6Y__ f§§T_ 2,4,5-T 2,4,5-T Q_62 1_32 3.4.5-T (B) 3,4.5-T- (B) -.O3 1.02 *- 2,4,S-T + dicamba 2,4,5-T + dicamba 0,56 1,26 Dicamba Dicamba Q_35 1,07 2,4,5-T + picloram 2,4,5-T + picloram Q_47 0.90 Tree doze-seedc Grub 0,26 1,07 Root plow-rake-seedc" Grub 1,09 1,85 Typical county Llano Llano Q a The net cash flow is total added cash sales less costs of brush control, added breeding livestock and increased annual operating costs plus the salvage value of cows and brush control (if applicable) at the end of the 20 year planning horizon. Interest charges were not included and the timing of cash flows was not considered. Herbicide treatments aerially applied at 0.5 lb/acre except 2,4,5-T (B) which indicates basal spray. C Native mixture of adapted species. 155 Table 68. Years required to recover initial investment in selected honey mesquite control alternatives and livestock based on cow-calf prodgction and $44/cwt cattle prices (1978 dollars) on deep sites in the Centra asin, Texas, 1978. Canopy cover and initial ‘ carrying_capacity-(acres/AU/yr) Treatmentb Moderate Dense Initial ' Maintenance __Y75Y__ Iii?- 2,4,S-T -. 2,4,5-T 15 9 2,4,s-'r (s) 2,4,S-T. (s) 2Q; 13 2,4,s-'r + dicamba 2,4,S-T + dicamba 16 i0 Dicamba Dicamba 18 11 2,4,5-T + picloram 2,4,5-T + picloram 20 17 Tree doze-seedc Grub 20 + 19 Root plow-rake-seedc Grub 20 18 Typical county ' Llano Llano a A 20-year planning horizon was utilized and no interest charges are included. The time period represents a "pay-back period" commonly used to evaluate in- vestment opportunities. Salvage values of cows and brush control (if appli- cable) are not included as part of the pay-out period, but would represent gross returns to the operation at the time of "pay-back." A 20 + indicates greater than 20 years will be required to recover the investment. b Herbicide treatments aerially applied at 0.5 lb/acre except 2,4,5-T (B) which indicates basal spray. c Native mixture of adapted species. 156 Table 69. Total weaned calf production (lb/acre/year) from selected honey mesquite control alternatives on deep sites Ln the Central Basin, Texas, 1978. ‘ +- e1 Canopy cover and initial A carrying capacity (acres/AU[yr Treatmentb Moderate Q§n§E_ Initial Maintenance (20) (22);‘ None (pretreatment) 16.6 15.0 2,4,5-T 2,4,5-T 21.1 22.0 Z,4.5-T (B) 2,4,s-'r (B) 23.2 23.4 2,4,5-T + dicamba 2,4,5-T + dicamba 23.2 22.0 ‘k Di¢8mb8 Dicamba 23.2 22.0 2,4,5-T + picloram 2,4,5-T + picloram 22,2 22.4 Tree doze-seedc Grub 25_0 25_5 Root plow-rake—seedc Grub 31_3 31_3 Typical county I Llano Llano a A 20-year planning period was utilized to determine the average production responses. b Herbicide treatments aerially applied at 0.5 lb/acre except 2,4,5-T (B) whic indicates basal spray. C Native mirture of adapted species. 157 Trans-Pecos The Trans Pecos covers l8 million acres (Table l) of mountain ranges interspersed.with basins and plateaus in.the western part of the State (Figure 1). Elevation ranges from.2,500 to 8,751 feet,and annual average rainfall is generally less than l2 inches. Anual frost—free period is 220 to 245 days. About 88 percent of the Trans~Pecos is native range of which roughly 62 percent is infested.with honey mesquite (Table l). Mbst of the infesta- tion is light canopy cover, scattered plants of honey mesquite occurring in association with other species. However, deep bottoland sites may support dense canopy covers of relatively large honey mesquite plants. Upland vegetation is dictated by altitude ranging from desert scrub to pinon and ponderosa pines (Pinus ponderosa Laws). The bottomlands are used exten- sively for grazing and support honey mesquite—desert scrub type vegetation. Soils vary widely from clays to sands depending on site. FYtn1l973 through 1977, herbicides were applied to an average of 20,120 acres annually, and 23,015 acres were treated each year with mechanical methods (Hoffman 1978). The Trans—Pecos is somewhat unique ir1that‘75 percent of the cows in the region are located in herds of 200 cows or more. Given the average for the state is 37 percent of the cows being in herds of 200 cows or more, the region can be characterized by large ranches which represent 26 percent J of the ranch firms in the region. For the state, there are but 7 percent of the ranch firms that have 200 cows or more (Table 3). Economic responses to brush control in the Trans—Pecos, as with the Edwards Plateau, were extremely variable which reflects the large differences among range sites in production potential. On deep sites that support l animal unit per 60 to 80 acres prior to treatment, anual 158 rates of return from aerial applications of 2,4,5—T averaged 6.4 percent (Table 70). On sites which initially supported l animal unit per 200 to 250 acres prior to treatment, aerial application of 2,4,5-T resulted in an average -0.45 percent annual rate of return. In comparison, aerial applications of dicamba to the more productive sites generated an average 2.5 percent annual rate of return, and a -3.6 percent rate of retun when 5 applied to the less productive sites. Economic evaluation of brush nanagement practices for the Trans—Pecos was complicated in that the lowlands and drainageways support most of the grazing livestock but may represent a relatively small portion of the land area in any specific nnnagement unit. Since the amount of lowland sites varies anong management units, it is not possible to evaluate the economic impact of treating only the bottomland sites. To estimate annual rates of return among alternatives discussed for the High Plains for cattle prices in the range, 34 to 54 cents per pound, the following adjustment factors are presented: Alternative Adjpstment factor 2,4,5—T 0.48 2,4,5—T + dicamba 0.46 Dicamba 0.42 2,4,5—T + picloram. 0.42 Tree doze 0.26 Tree doze—seed natives 0.2l Tree doze—roller chop- seed natives 0.20 Root plow~roller chop- seed natives 0.2l Treatment costs for aerial herbicide application in the Trans—Pecos were the same as for the High Plains (Table 5). Costs for mechanical 159 .e~em\n~ m.o em eefiflmme >-mHaee wewwefineez .>-m:¢e mcezeea new memee eeeuwe Hfifiz cefiemflwcfi measmme mmeeeem mesh wcfinnm >@ eves en xme cameo» we meuma Hmcfieec we eexaea we eeeE@ewe :< weeemafi ce@eeHw:~ en:~e:@ we: ow cnsuea we weeea ~m:::e .w::P .me@ee@m eeememe.we ensexfis e>@emz .weee~ ~me~ eze ee eeee :e@ee~w:H eeesmme cm .c~:ee~ we meemw ~eeu eepevfimcee ewe new .wae-ee wwmfi ecepmcee :@ eeeee@e»Q QMQB mceseew new memeu .xeeeme>H~ wcfiweenn ecu Henecee swans cfi Hmefimee e:eEewe>:@ use wcfiemaeme Hfim weewfimcee cnseee we ewe» ea? 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In four of the eight broad situations evaluated, cost reductions were required for aerial applications of 2,4,5-T to yield a 9 percent annual rate of return (Table 72). In two cases, the required cost reduction was greater than the initial treatment cost and subsequent treatments were required to be reduced. Although simple averages do not effectively relate treatment effectiveness on an absolute basis, they are useful for comparative purposes} Average initial cost reductions for aerial application of 2,4,5-T was 2.78 dollars per acre, 3.21 dollars per acre for 2,4,5—T + dicamba, 5.70 dollars per acre for dicamba and 6.89 dollars per acre for 2,4,5—T + picloram to yield a 9 percent annual rate of return on the investment in honey mesquite control on the Trans-Pecos. In l6 of the 31 situations evaluated, aerial applications of herbicides resulted in"a positive increased annual net cash flow (Table 73). Average increased annual net cash flow across all mesquite infestation/site situations ~was\1h5 cents per acre for aerial application of 2,4,5-T, 39 cents per acre for 2,4,5-T-+ dicamba, 19 cents per acre for dicanba and 23wcents for 2,4,5-T + picloram (used in seven of the eight situations). Because of high treatment costs (Table 71), mechanical alternatives resulted in low annual Fates Of return (Table 79), and yielded relatively small increases in annual net cash flow (Table 73). Time to recover the initial investment ranged from 9 to more than 20 years from aerial applications of 2,4,5—T (Table 74). From 15 to nnre than 20 years were required to recover the initial investment in dicamba, Q‘ and pay back period generally exceeded 20 years for the mechanical practices. 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Aerial application of 2,4,5-T, 2,4,5-T + dicamba or dicamba increased annual average production to 7.6 pounds per acre. Mechanical treatments increased total production to 9.1 pounds per acre representing a 153 percent increase in productivity. However, it must be recognized that in any given situation, a relative smaller portion of the land supports the majority of the grazing animals on the Trans-Pecos. The lowlands with deep soils and a good probability for collecting runoff produce most of the range forage but may represent less than 20 percent of the land area. This analysis assumed overall treatment of the management unit, not just treatment of key sites. 166 .mo@uomm noummwm mo oaspxfis o>@~mz u n .mom:ommon cowuuswoam owmno>m oz» ocflenouov ow wvuflfifius mm: uofinom w=@==@H@ ~m@>-¢~ < m .mnum\n~ m.o um wo@~mmm xfiflmfinom mowfiofinnmz ocmau ommm ~m w=@>o4 ofiwfimonm ommm flm spomwwsz nowum m@>mo mmow mo@»::ou ~mu@m>h l l l l l l 5.2 l n26 .z@m-.€fi. , am-wn|zo~m poem I| ll Aw.w ll ll ll ll Plm~VQN UUQOWIQOLU ~o-oa|zo~m.~oom ma: l l l l l l l elmifim Ufiamiozu ~w~Ho~|o~ow uwpe || ~.¢ o.w w.o~ ll ll ll || h|m.v.N owm@m|o~ow ooaw ll >.m o.“ ~.@ m.¢ o.a ll >.N~ P-m.¢.~ w~ow ooue ll ~.< @.@ w.- ~.< @.@ ~.@ >.N~ Emhofluflm + @-m.¢.~ Empofiuflm + @-m.¢.~ w.@ o.m w.“ w.¢~ ~.¢ ~.@ m.@ ~.- wnsmufla wpsmufia w.@ o.m w.~ w.¢~ ~.v ~.m m.@ ~.- mnsmufin + @-m.¢.~ mnsmufiw + @-m.<.~ m.@ @.m w.~ @.@H H.¢ ~.@ m.@ ~.N~ @-m.¢.~ P-m.¢.~ ~.n m._ ~.~ ~.< N.“ m.m @.¢ @.m _ Aucoewmwwwonnv ocoz ~m@v AQmN~ ~Qm_V hcwv AQONV ~¢@H~ AQBV AQQV @U=@=@~=M@z ~m@~H=H lomcoalwoz omcuo @»m~@@o2 @p=@E~@@~@ mjmom 3O-m£m wfiom @000 ->\J<\no»ud~ >»@umnmu ucM>~»mu Mmflwflcfi cam owfim xn »¢>cu »@oc¢u .w>mH .mmxmP .mou®m|w:mwP Q .mN @~@m@ oz» cw mo>@wmcnuu~m Hoawcou wwwswwoe >020: nopuofimw EOMM fi~>\owum\n~v cofiwuswoum wfimu cwcmwz Mmpok 167 DISCUSSIQN These analyses are most applicab1e:flarevaluation of alternatives for improving honey mesquite-infested rangeland at the firnllevel and do not consider total industry supply impacts. They may be most useful when results fnun the selected alternatives are viewed on a comparative rather than an absolute basis in the decision-making processes. The assessment of relative profitability among the alternatives considered each mesquite canopy cover/range site/major land resource area situation as an isolated entity. Thus, application of the results will require adjustment for the relative proportions within a management unit. Moreover, the approach for this smxhzdoesnot consider interaction of treated with untreated management units within the ranch firm. Ignoring potential economic synergisms among management units receiving different treatments may result in conservative estimates of profitability. Because of differences in requirements of management at the firm level, no single economic criterion was felt to be the "best" for realistic comparisons among treatment alternatives. For example, use of annual rate of return as the indicator of economic efficiency at the firm level does not necessarily consider management investment criteria for increasing cash flow, amount of capital available for investment, limitations- on payback period, and risk or uncertainty of the investment. Economic criteria must be matched with short and long term management goals for final judgment of acceptability of any alternative. Therefore, our analyses include several economic criteria for comparative evaluation of the treat- ment alternatives. 168 One of the uses of economic analyses is to evaluate the impact of constraining or eliminating use of any given practice. Presently, the potential for elimination of the herbicide 2,4,5-T serves as a good example. Since there are production response differences and differences in producer needs and objectives, it is not possible to identify and single "best treatment" at the ranch firnllevel. However, based on these analyses of alternatives identified in our survey, aerial application of 2,4,5—T was generally the most profitable treatment for improvement of rangeland infested with honey mesquite. k Utilizing the highest annual rate of return for aerial application of 2,4,5—T from each vegetation region, the estimated statewide average annual rate of return was 15.9 percent. Returns from application of the "next best" herbicide alternative, dicamba, averaged ll.4 percent. Thus, shifting to the "next best" economic alternative would result in a reduction of about 28 percent in the annual rate of return for herbicidal control of honey mesquite. I The highest annual rate of return for a specific resource situation involving the use of 2,4,5-T over the 20—year planning horizon was approximately 25 percent,a1though zero and negative rates of return occurred in a few instances. Generally the order, based on decreasing annual rates of return, of herbicides was 2,4,5-T >2,4,5—T + dicamba >dicamba, >2,4, 5-T + picloram. However, there were specific situations where 2,4,5-T + picloram,was more profitable than the use of dicamba. Because production responses to the herbicides were the same with the exception of 2,4,5-T + picloram which controls a broader spectrum of associated species than the other chemical alternatives, the ranking relative to economic efficiency followed treatment costs. Although aerial 169 application of herbicides generated relatively high annual rates of return on the investment, resultant increases in annual net cash flow were generally not as high as when mechanical land conversions were applied to the more productive sites. Mechanical methods were characterized by relatively high initial costs and lower annual rates of return than obtained from herbicides but generally generated greater increases in annual net cash flow than herbi- cide use. For example, selecting the "best" mechanical treatment (highest rate of return) from each resource region resulted in an average rate of return of 5.7 for mechanical treatments. When‘the establishment of tame pasture to kleingrass or coastal Bermudagrasswas selected an an alternative net cash flows were considerably higher than obtained from herbicides because of the intensive production requirements. Annual maintenance costs were less when native grasses were utilized for seeding projects; however, annual rates of return and increases in annual net cash flows fronmnative seedings were usually lower than when tame pastures were established. Because of relatively high initial treatment costs without concomitant production increases, mechanical practices such as tree dozing not followed by artificial seeding produced low annual rates of return and would not be considered as being economically feasible by ranch managers. The relatively lowecost mechanical method of chaining, uS€d in a treatment sequence with aerial spraying, was competitive with spraying in most cases. For the 44 dollar per hundredweight situation presented in this study, herbicides generally have the economic potential of generating acceptable rates of return (9 percent was selected as "acceptable" for this study) without initial treatment cost reductions. However, for the "better" mechanical treatments, initial costs would have to be reduced approximately 170 50 percent (or more in many specific cases) in order to yield a 9 percent annual rate of return. Thus, mechanical treatments may not be adopted by ranch managers in the future unless government "cost sharing" (or other neans to reduce initial costs) are continued and perhaps increased due to the energy price unpact on the projected cost of mechanical treatments. Performance of the honey mesquite control alternatives varied among major land resource areas. However, the variation appears to be related to rather broad differences in rainfall and soils which allows logical combi- nation of shnilar major land resource regions to simplify discussion. For example, the brush problem of northwest Texas (High Plains, Rolling Plains, Rolling Red Plains) is predominantly honey mesquite. This region supports almost 30 percent of the honey mesquite-infested acreage on Texas range- land. Based on average response across all situations evaluated for the region, aerial application of 2,4,5—T for honey mesquite control generated an average annual return of ll.5 percent and averaged 9.3 percent for mesquite control with all aerially-applied herbicides (50 situations). Average annual net cash flow was increased by 0.82 dollar per acre. In comparison, mechanical conversion by root plowing honey mesquite-infested sites and seeding a mixture of native grasses in northwest Texas generated an average annual rate of return of 2.4 percent but increased average annual net cash flow by 1.20 dollars per acre. Mreover, the mechanical conversion was applied to only the more productive sites cmpared to the more extensive use of herbicides. Mechanical conversion of honey mesquite— dominated sites to tame pastures requires even more careful selection of sites and will require more intensive cultural inputs, especially of fertilizer, than conversion by seeding native forage species. However, establishment of kleingrass pastures on applicable sites using root plowing 171 for brush control resulted in an average annual rate of return of 5.9 percent, and increased annual net cash flow by an average of 4.85 dollars per acre. This indicates that if mechanical treatments are to be utilized, ranch managers may need to consider complete conversion to tame pastures and intensify livestock use rather than simply improving native range. Payback period for the investment in establishing kleingrass pasture ranged from l2 to 20 years compared to 15 to more than 20 years for root plowing and establishing native grasses, and 5 to more than 20 years for aerial spraying as averaged across results from all herbicides (payback ranged from 5 to 13 years for application of 2,4,5-T). Based on these results, it appears that honey mesquite control with herbicides has greatest economic potential on an extensive basis in north- west Texas and on sites not capable of supporting tame pasture. An acceptable annual rate of return on the investment, assumed to be 9 percent for this study, is possible from treating most sites infested with honey mesquite. Since initial treatment costs are relatively low, a given acreage can be treated with a considerably smaller amount of investment capital, compared to costs of mechanical methods. This consideration could reduce risk to the ranch manager because he would have more cash and credit reserves by using herbicides than he would with mechanical alternatives. However, if the investment in herbicides and kleingrass establishment meets the managers mininmnxacceptable rate of return, it must be realized that about 6 acres of mesquite must be aerially sprayed to increase annual net cash flow to the finn that can be increased from establishing 1 acre to kleingrass. Therefore, establishment of tame pastures to adapted sites may allow significant increases in the net cash flow of the firm if the management is willing to accept a relatively low rate of return on the 172 investment. Mre research is needed to optimize the proportion of acreage for treatment with aerial application of herbicide in relation to that which should be established to tame pasture. Northcentral-central Texas (North Central Prairie, Cross Timbers, Grand PTairie~ Blackland Prairies1uuiTexas Claypan) isan agriculturally productive area of the State on which honey mesquite control practices are relatively profitable ventures. For example, average rates of return over the 24 situations for aerial application of 2,4,5-T was 12.9 percent and averaged 8.5 percent across all herbicides (92 analyses). Root plowing ,& and seeding native grasses resulted in an average annual rate of return of 3.8 percent, and root plowing followed by establishment of kleingrass pastures generated a 3.7 annual rate of return, based on 44 cents per pound beef prices, 1978 costs,and a 20-year planning horizon. Increased annual net cash flow was 1.56 dollars per acre from 2,4,5-T and averaged 1.39 dollars per acre from all herbicides, 1.64 dollars per acre from root plowing and seeding native grasses_ and 4.10 dollars per acre from establish- ment Of kleingrass paStHreS- Thus, based on annual rates of return and potential for increasing net cash flow, use of herbicides for mesquite contrtfl.appears to be a relatively profitable venture for ranch managers to consider in north- central and central Texas. However, herbicide use is constrained, much more severely than in northwest Texas, by the proximity of susceptible crops to rangeland needing improvement. Therefore, complete land conversion Y0 tame Pasture may be justified. Primary use of herbicides in South Texas is on the Rio Grande Plain rather than the Coast . Prairie where it is constrained by susceptible crop production. Herbicides generated higher annual rates of return and slightly smaller increases in annual net cash flows than root plowing, and seeding 173 to native grasses. For exmnple, herbicide application for honey mesquite control increased annual net cash flows by an average of 1.99 dollars per acre oanpared to 2.12 dollars per acre for root plowing and seeding. This responsiveness is indicative of the production potential of native forage stands on the Rio Grande Plain. In southcentral Texas, the Edwards Plateau and Central Basin, average annual rate of return from aerial applications of 2,4,5—T for honey mesquite control was 10.9 percent, and averaged 8.8 percent across all herbicide alternatives. Annual rates of return from aerial spraying exceeded that from mechanical practices. For example, on the average, root plowing, raking,and seeding to native grasses generated. annual rates of return of about 2.8 percent when applied to deep soils. A 6.3 percent rate of return resulted from utilizing the same mechanical practices to establish kleingrass pastures. However, establishment of kleingrass pasture increased annual net cash flow by 6.20 dollars per acre compared to an average increase of 1.75 dollars per acre following aerial application of 2.4.5-T. Annual rates of return in arid far west Texas from aerial application of 2,4,5-T for honey mesquite control, averaged 4.3 percent, and ranged from -4.4 to 11.7 percent. Although unweighted averages are being used for comparison, they indicate the need.for treatment only on the most productive range sites with deeper soils that receive runoff water. Annual rate , of return, averaged across all herbicides, was 2.4 percent. Root plowing, roller chopping and seeding adapted sites to native grasses generated a 2 percent rate of return. Often a relatively small proportion of any given management unit treated in the Trans Pecos produced most of the response to a treatment; however, the evaluation of these small, but highly productive sites was not feasible as a part of this study. 174 It should be emphasized that ranch firnlnanagers should select brush nanagement practices on criteria other than an annual rate of return. Given a minimum acceptable annual rate of return, minimal limitations on investnent capital, an acceptable risk return level and a need for well- defined annual net cash flow, a producer could justify a practice with a lower percentage yield, but one that would allo a greater absolute value of net ranch returns over time. Thus, a producer might prefer a mechanical practice if it met his minimum level of return and yielded a higher net cash flow than a herbicide practice. Another important question in selecting a brush management alternative relates to capital requirements. Dicamba is projected to require 36 percent more investment capital per acre than 2,4,5-T, assuming elimination of other herbicides would not result in a price increase in dicamba. These increases in capital investment, based on any given cattle market price framework, would cause corresponding increases in the time required to recover the invest“ ment in the treatment. This consideration is significant in that borrowing for brush management may present problems to Texas Ranch firms since the pay out period for any given practice may exceed the pay back period. Thus, cash flow problems could be anticipated if shifts to more expensive treatments were demanded, particularly for the small operators. In Texas, 93 percent of all ranch firms operate with fewer than 200 cows. Cash flow problems could be amplified for this group by elimination of the more profitable honey mesquite control practices. Larger operations can more easily shift cash flows to finance range improvenents than can small operators who by necessity consume a larger portion of the cash flow. 175 ACKNOWLEDGMENTS The authors are grateful to Rhett Johnson and D.B. Polk, Sr., Soil Conservation Service; Temple, Texas and to the Range Conservationists throughout the State who participated in this study. The efforts of Julia Scifres in typing and preparing this manuscript are deeply appre- ciated. This research.was partially suported by funds from.the Southern Region Pesticide Impact Program. 176 REFERENCES CITED BGESOUI, S.L. and C.J. Scifres. 1977. Populatign reagtigns of selected game species to aerial herbicide applications in South Texas. J. Range Manage. 30:138-142. Bontrager, O.E., C.J. Scifres and D.L. Drawe. 1979. Huisache manage- ment by grubbing. J. Range Manage. 32 185-188, Bovey, R.W., F.S. Davis, and H.L. Morton. 1968. Herbicide combinations for woody plant control. Weed Sci. 16:332-335. Bovey, R.W, and C.J. Scifres. 1971. Residual characteristics of picloram in grassland ecosystems. Texas Agr. Exp. Sta. Bull. 1111. 24 p. Boykin, C.C., Jr. 1960. Costs of root plowing and seeding rangeland, Rio Grande Plain. Texas Agr. Exp. Sta. MP. 425. 8 p. Darr, J.W., and D.A. Klebenow. 1975. Deer, brush control, and livestock on the Texas Rolling Plains. J. Range Manage. 28:115-119. Fisher, C.E., C.H. Meadors, J.P. Walter, J.H. Brock and H.T. Wiedemann. 1974. Influence of volume of herbicide carriers on control of honey mesquite. Texas Agr. Exp. Sta. Prog. Rep. 3282. 4 p. Fisher, C.E., H.T. Wiedemann, J.P. Walter, C.H. Meadors, J.H. Brock and B.T. Cross. 1972. Brush control research on rnageland. Texas Agr. Exp. Sta. IVIP—1043. 18 p. Godfrey, C.L., C.R. Carter and G.S. McKee. Undated. Land resource areas of Texas. Texas Agr. Ext. Ser. B#1070. 24 p. Gould, F.W. 1975. Texas plants. A checklist and ecological sunnnry. Texas Agr. Exp. Sta. MP—585 (Rev.): 121 pp. 177 Hamaker, J.W., H. Johnston, R.T. Martin and C.T. Redemann. 1973. A picolinic acid derivative: A plant growth regulator. Science 1412363. Hbffman, G.O. 1978. Texas brush and weed control acreages. Texas Agr. Ext. Ser. RM 3-1 (March 1978): 24 pp. (mimeo). Hcpkin, J.A., P.J. Barry and C.B. Baker. 1973. Financial management in Agriculture. Interstate Printers and Publishers, Inc. 459 p. Holt, C.E. (Ed). 1976. Grasses and Legumes in Texas. Development, Production, and Utilization. Texas Agr. Exp. Sta. Res. Mcn. 6C:479 p. Kothmann, M.M. (Ed). 1974. A glossary of terms used in range manage- ment. Soc. Range Manage., Denver, Colo. 36 p. Mutz, J.L., C.J. Scifres, D.L. Drawe, T.W. Box and R.E. Whitson. 1978. Range vegetation after mechanical brush treatment on the Coastal Prairie. Texas Agr. Exp. Sta. Bull. 1191. 16 p. Osborn, J.E. and G.V. Witkowski. 1974. Economic impact of brush encroachment in Texas. S. J. Agr. Econ. (Dec):95-100. Research.Cbnnuttee, Association of Texas Soil and Water Conservation Districts. 1970. Conservation Problems in Texas. 37 p. Scifres, C.J., J.H. Brock and R.R. Hahn. 1971. Influence of secondary succession on honey mesquite invasion in North Texas. J. Range Manage. 24:206-210. Scifres, C.J., R.R. Hahn and J.H. Brock. 1971. Phenology and control of connnn broomweed on Texas rangelands. J. Range Manage. 24:370-373. Scifres, C.J. and G.O. Hoffman. 1972. Comparative susceptibility of honey mesquite to 2,4,5-T and dicamba. J. Range Manage. 25:143-145. Scifres, C.J. (Ed). 1973. Mesquite. Texas Agr. Exp. Sta. Res. Monogr. 1:84 p. 178 Scifres, C.J., M.M.-Kbthnenn and G.W. Mathis. 1974. Range site and grazing systenxinfluence regrowth after spraying honey mesquite. J. Range Manage. 27197-100. Scifres, C.J. and D.B. Polk, Jr. 1974. Vegetation response following spraying a light infestation of honey mesquite. J. Range Manage. 27:462-465. Scifres, C.J. and M.G. Merkle. 1975. Herbicides and good.nnnagement improves range pastures. Weeds Today (Spring) 5-7. Scifres, C.J., G.P. Durhanland J.L. Mutz. 1977. Range forage production and consumption following aerial spraying of mixed brush. Weed Sci. 25:48-54. Scifres, C.J. 1979a. Brush Management. Principles and Practices for Texas and the Southwest. Texas A&M Univ. Press (In press). Scifres, C.J. 1979b. Range improvement practices for the Coastal Prairie: Needs, present applications, and research advances. Symposiun1Proc., Welder Wildlife Found., Sinton, TX (Oct. l4): (In press). Smith, Alan. Personal written communication. Dec., 1978. Scenerio for Fbod and Agriculture. U.S. Dep. Agr., Econ., Stat., and Coop. Serv. Smith, H.N. and C.A. Rechenthin. 1964. Grassland Restoration. The Texas brush problem. U.S. Dep. Agr., Soil Conserv. 33 p. Tanner, G.W., J.M. Inglis and L.H. Blankenship. 1978. Acute impacts of herbicide strip treatment on mixed-brush-white-tailed deer habitat on the northern Rio Grande Plain. J. Range Manage. 31:386-391. Whitson, R.E., S.L. Beascn1and.C.J. Scifres. 1977. Economic evaluation of cattle and whitetailed deer responses to aerial spraying of mixed brush. J. Range Manage. 30:214-217. Wiedemann, H.T., B-T- CTOSS, and C.E. Fisher. 1977. Low-energy grubber for controlling brush. Trans. Amer. Soc. Agr. Engr. 20:210-213. 179 Workman, D.R., K.R. Tefertiller and C.L. Leinweber. 1965. Profitability of aerial spraying to control mesquite. Texas Agr. Elxp. Sta. MP. 425. 8p. 180 U! 1O . APPENDIX Definition of Terms Animal unit. Considered to be one mature (1000 lb.) cow with calf or the equivalent based upon average daily forage consumption of 26 lb/day of dry matter. Animal-unit month (A.U.M.). The amount of feed or forage required by an animal unit for one month, i.e. one month's grazing for one animal unit . Break-even analysis. A technique used to identify the minimum quantity ‘ of output that would be necessary for recovery of a given investment and its related operating cost. Browse (n). 'Ihat part of leaf and twig growth of shrubs, woody vines and trees available for animal consumption. (v) To consume browse, cf. graze woody plants. i511. A growth of shrubs or small trees usually undesirable for livestock or timber management but which may sometimes be of value for browse and/or for watershed protection. Brush control. Reduction of brush to reduce its competition with more desirable species (for grazing) for space, moisture, light, and nutrients. Brush management. Management and manipulation of brush stancb to achieve specific management objectives, brush control is one brush management technique. Brushland. An area covered primarily with brush. Calf crop. The number of calves weaned from a given number of cows bred‘ usually expressed in percent. Qangpy. The vertical projection downward of the aerial portion of shrubs and trees, usually expressed as percent of ground so occupied. ll. 13. 14. 15. 16. 17. 18. 19. 20. 181 Capital budgeting. The addition of assets to a buiness. Carrying capacity; The maxinmmxstocking rate possible without inducing damage to vegetation or related resources. It nay vary from year to year on the same area because of fluctuating forage production. Class of animal. Age and/or sex grou of a kind of animal. Example: cow, calf, yearling, ewe, fawn, etc. Constant dllars. Dollars of constant purchasing power. The current market value divided.by a price index provides an estimate of purchasing power for the base year of a given price index. Credit. An individual's borrowing capacity. The ability to secure money, goods or services in the present against the promise to pay for them in the future. Deferment. Delay or discontinance of livestock grazing on an area for an adequate period of time to provide for plant reproduction, establish- ment of new plants, or restoration of vigor of existing plants. ef. deferred grazing. Depreciation. The allocation over time of the cost of an asset which will be used up over a long period of time. Discount rate. An interest rate used in the capital budgeting process that represents the maximum rate of return the investment could earn in its most favorable alternative use. Economic efficiency. The relationship between cost of production and the combination of resources to produce a given level of output. Maximum economic efficiency occurs at the point of maximum production for a given level of expenditure. Economic enterprise. A ranch business of sufficient resources to provide an accepted standard of living for a family. 10L 21. Effective éprecipitation. That portion of total precipitation that becomes available for plant growth. It does not include precipitation lost to deep percolation below the root zone or to surface rlmoff or to evaporation. 22. Financial risk. The impact that the increased use of credit may have on the firms potential gain or loss of equity. As the level of borrowing increases, financial risk increases and unfavorable events have a greater impact on the business than do favorable events. 23. Fixed cost. Costs which continue over a specified time period regardless 1 of what happens to the level of production. 24. 2932153. All browse and herbaceous foods that are available to grazing animals. 25. _G_a_me_;. Wildlife species so designated by law and the harvest of which is regulated by law. 26. Grassland. Land on which grasses are the dominant plant cover. 27 . Grazing distribution. Dispersion of livestock grazing within a mnage- ment unit or area. f, 28. Grazing management. The manipulation of livestock grazing to accomplish a desired result . 29. Grazing management plan. A program of action designed to secure the best practicable use of the forage resources. 30. Grazing unit. An area of rangeland, public or private, which is grazed as an entity. 31. Internal rate of return. That rate of armual return which results in a x zero net present value of a given investment over a given planning horizon. 32. Kind of animal. An animal species or species group such as sheep, cattle, goats, deer, horses, elk, antelope, etc. 33. 35. 36. 37. 38. 39. 41. 43. 183 Liquidity. Relates to the finn's capacity to generate sufficient cash to meet its financial commitments as they fall due. Net cash flow. Total cash inflows less all cash outflows for a specific period of time. It represents a flow of cash that can be withdrawn by the owner or reinvested in the business. Net present value. A technique utilized for evaluating the economic feasibility of a given investment. The technique relies on net cash flows and accounts for differences in the timing of the flows by use of an appropriate discount rate. Overgrazing. Continued overuse creating a deteriorated range. Overstocking. Placing a given number of animals on an area that will result in overuse if continued to the end of the planned grazing period. Overuse. Utilizing an excessive amount of the current year's (vegetation) growth which, if continued, will result in overgrazing and range deter- ioration. Partial budget. A technique to identify the net economic benefits arising frcn1a.given change in a business organization. Pasture. A grazing area enclosed and separated from other areas by a fence. Pasture, tame. Grazing lands, planted to primarily introduced or domesticated native forage species, that receive periodic renovation and/or cultural treatments such as tillage, fertilization, mowing, weed control, and irrigation. Planning horizon. The length of time used for evaluating a given investment decision. Proper grazing. The act of continuously obtaining proper use. 184 44. Proper stocking. Placing a number of animals on a given area that will result in proper use at the end of the planned grazing period. Continued proper stocking will lead to proper graging. _ 45. §roper_u§g, A degree and time of use of current year's growth which, if continued, will either maintain or improve the range condition consistent with conservation of other natural resources. 46. Eange, Ehbraces rangelands and also many forestlands which support an understory or periodic cover of herbaceous or shrubby vegetation amenable to certain range management principles or practices. 47. Range condition. The current productivity of a range relative to what that range is naturally capable of producing. 48. Bangeland. Land on which the native vegetation (climax or natural potential) is predominantly grasses, grass-like plants, forbs or ,i shrubs suitable for grazing or browsing use. Includes lands reve- getated naturally or artificially to provide a forage cover that is managed like native vegetation. Rangelands include natural grasslands, savarmahs, shrublands, most deserts, tundra, alpine communities, coastal marshes and wet meadows. 49. Range site. A distinctive kind of rangeland, which in the absence of adnormal disturbance and physical site deterioration, has potential to support a native plant ccnnmmity typified by an association of species different from that of other sites. This differentiation is based upon signficant differences in kind or proportion of species, or total productivity. 50. Risk—return preference. A managerial behavioral characteristic which is used to explain logical investment choices given a high return-—high risk investment choice versus a lower return--lower risk choice. 51. 52 . 53. 55. 56. 185 Salvage value. Useful life of an investment which remains at the end of a given planning horizon. Savarmah. A grassland with scattered trees, whether as individuals or clmlps; often a transitional type between true grassland and forest. S_9_dg3_ ass. Stoloniferous or rhizomatous grass which forns a sod or turf. Stocking rate. The area of land which the operator has alloted to each animal-unit for the entire grazable period of the year. Variable cost. A financial input requirement that changes with changes in production over a specified planning period. Yearlong grazing. Continuous grazing for a calendar year. [Blank Page in Original Bulletin] [Blank Page in Original Bulletin] - . ‘ y a . > ~\ _ . u '_ ; . ,‘ _ , . _u ' \ ~ ‘ ‘ . A » » I . a ' q - ‘v ‘ ' . . ‘ x n . - ' - n _ - r * _ 4 - ~ 4 ¢ . y} , 2 , ' v ' , . .» \ J , 1 ' . 4 . - ~ c" x _~_~¢ 3 ~ a ~ e \ . i f 0 1 ¢ .. a Q , I v s r \ ‘ v \ 9' x 3 ' \- r 1 4 ‘ \ ‘. _ a 4 2 n ‘= l a \ I _ u - _ _ . n flit’! - 1 a - 5 n I .1 - 4 ,- All programs and inforrnation of The Texas Agricultural Experiment Station are available without regard to race, ethnicla origin, religion, sex, or age ._ ‘a 1M -7-80