TEXAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, Director College Station, Texas BULLETIN NO. 644 JANUARY, 1944 THE CHEMICAL COMPOSITION OF FORAGE GRASSES FROM THE GULF COAST PRAIRIE AS RELATED TO SOILS AND TO REQUIREMENTS FOR RANGE CATTLE J. F. FUDGE and G. S. FRAPS Division of Chemistry UBRARY_'( A, {Q1 m mama BF TERM; AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS F. C; BOLTON, Acting Prgsident D-12-144-4500 [Blank Page in Original Bulletin] Sufficient phosphoric acid (phosphorus) for best results is frequently @ supplied to grazing animals by forage grasses grown on the soils of the Gulf Coast Prairie. Protein in the forage may be insufficient for best results at times, especially when the grass is old or dried up. Sufficient lime (calcium) is supplied by nearly all forages. Fertilization of pastures can increase the protein and phos- phoric acid content of the grasses, _as well as increase the yields.____ The grass which grew after mowing contained more phosphoric acid and protein than unmown grass available at the same time. Chemical analyses were made of 1,144) samples of different species of forage at various stages of growth from nearly 100 locations in the Gulf Coast Prairie of Texas. The chemical com- position of the samples varied widely with differences in species, stage of maturity, and location. Protein and phosphoric acid de- creased markedly with advancing maturity, crude fiber and nitro- gen free extract in general increased slightly, and changes in lime were irregular. Protein and phosphoric acid in nearly all of the samples ranged from fair to very deficient. As the plants became older, the proportion of samples which were deficient or very de- ficient in protein and phosphoric acid increased markedly. At the mature stage of growth, 92% of the samples were deficient in protein and 96% were deficient in phosphoric acid. Very few of the samples were deficient in lime. Johnson, Dallis, and Bermuda grasses were in general higher in protein, phosphoric acid, and lime than were the principal native species sampled. Soils which contained relatively high percentages of nitrogen, active phosphoric acid and active lime produced young grass which contained higher percentages ofprotein, phosphoric acid, and lime than were found in grass produced on soils which contained lower amounts of these constituents. The relation of the compo- sition of the soils to the composition of forage at intermediate and mature stages of growth was not so clear as for young forage. CONTENTS » a Pagej Introduction ............................................................................................................... .. 51g Description of the GulfCoast Prairie“.-. ......................................................... .. 5 , Samples used ............................................................................................................ .- 6 Qommon and botanical names of plants ................ ......................................... .. 7 t Most important forages on the pastures..- ......................................................... .. 7 Average analyses of the various species of forage ........................................ .. 9 Average feed constituents in the various species of forage ........................ ..14 Grades of constituents of forage ........................................................................ ..16 Distribution of samples according to grades of constituents ...................... ..18 A The chemical composition of the soils .............................................................. ..24 p Relation of chemical composition of samples of forage to different groups of soils ................................................................................ ..25 Effect of the general nature of the soils .................................................. ..26p Effect of the chemical composition of the soils .................................... ..28c Effect of some pasture practices upon the chemical composition of forage ........................................................................................ ..31‘ Effect of mowing the pastures .................................................................... ..31 Effect of fertilization of the soils .............................................................. "33 Acknowledgment ...................................................................................................... ..3 V, Summary ................................................... ................................................................ Literature cited ........................................................................................................ y , hmnrr~l£:»_-.t.t@ 91.1’; 1.". l‘ 1? f’- THE CHEMICAL COMPOSITION OF FORAGE GRASSES FROM THE GULF COAST PRAIRIE AS RELATED TO SOILS AND TO REQUIREMENTS FOR RANGE CATTLE J. F. Fudge, Chemist, and G. S. Fraps, Chief Division of Chemistry An adequate supply of minerals in the rations consumed by animals l as long been recognized as of importance in their growth and mainten- ance. Recent intensive and extensive studies have shown that a number of ‘seases and other evidences of malnutrition in range animals are defi- 1 'tely associated with a deficiency of minerals in the available forage (1, , 5, 6, 9, 10, 18, 19, 27, 28, 31, 32, 33, 34). The percentage of each con- tituent in the forage is the chief determining factor in the development of i utritional disturbances. Animals grazing on ranges on which there is an bundance of forage may show marked evidences of mineral deficiencies. i e quantity of forage eaten by an animal is limited; if the percentage f a. constituent in the forage is sufficiently low, the quantity of the con- tituent eaten will be insufficient for satisfactory growth, maintenance, or > production. ‘ Phosphoric acid is the constituent usually deficient in Texas. The ymptoms of its deficiency include the chewing of wood, bones, or other ubstances (pica), stiffness of the legs, swollen joints, emaciation, and sually poor, unthrifty appearance and, in some cases, a lower production f calves. Various names have been used for these abnormal conditions; hese include “creeps” in Texas, “stiffs” and “sweeny” in Florida (4), styfsiekte” in South Africa (9), and “cripples” or “pegleg” in Australia 34). Bone chewing may lead to other serious diseases, such as “1oin dis- se” in the Gulf Coast region of Texas (26), “lamsiekte” in South Africa 33), and others (31). A deficiency of calcium may also cause disturbances 7 the health of animals, but these are of much less frequency and im- ortance in Texas than those due to a deficiency of phosphoric acid. De- ciency of either phosphoric acid or lime may result in decreased growth ~ d unthrifty condition, even when no symptoms of disease are visible. A w protein content is often associated with a low phosphoric acid content - forage plants (14, 15, 17), so that forage which is deficient in phos- oric acid is often deficient in protein. Disturbances in nutrition due to deficiency of protein in the forage may accompany and accentuate those - e to a deficiency of phosphoric acid. Deficiencies in cobalt, copper, and l‘ elements, have been found elsewhere but not in Texas (7). DESCRIPTION 'OF THE GULF COAST PRAIRIE The area called the Gulf Coast Prairie of Texas covers about 8,000,000 s of land in a nearly flat strip of country along the Gulf Coast, vary- g from 20 to 80 miles in width and extending from the Louisiana line to M the San Antonio River. The surface is nearly flat except for local near the interior border, where it may be gently undulating. Surface 6 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION _ drainage is slow because of the level topography; subsurface drain very slow because of the heavy, dense clay subsoil and substrata underlie most of the soils. A narrow fringe of marshy or semi-marshy. extends along the coast line. Rainfall is heavy over most of the regi, The principal soil series is called the Lake Charles and is com? principally of dark-colored soils with heavy texture, but soils of light ture occur in small areas throughout the region. A narrow belt of , colored, sandy soils of the Hockley and Katy series occurs along l‘. terior border of the region. Small areas of similar soils of the Edna =_ occur in the region, usually in association with Lake Charles soils. it soils which occur in marshy or semi-marshy areas along the coa called Harris soils. Considerable areas of alluvial soils occur alol lower stretchés\of a number of rivers. Upland" soils of the regio; usually fairly well supplied with total nitrogen, fair to good in potash lime, low to very low in total phosphoric acid and active phosphoric x and are usually slightly acid (13). Alluvial soils usually contain ‘g quantities of these constituents than the upland soils. 1 SAMPLES USED " Forage samples, numbering 1140, were collected during 1936, ; 1938, and 1940 from nearly 100 locations in counties well distri, through the area, including Brazoria, Calhoun, Chambers, Fort Bend,; veston, Harris, Jackson, Jefferson, Liberty, Matagorda, Orange, Vi f and Wharton. Locations from which samples were taken were accur described so that subsequent samples of forage and soil could’ be w‘ from the same place. The stage of maturity (whether young, w?’ young, in bloom, or mature) of each species of forage was noted and soil type identified. All of the important species of forage on each tion were sampled.’ Individual samples consisted entirely of the c b year’s growth of a single species. The samples, after cutting, were p loosely in a cloth bag, dried at 45°C, ground in a Wiley mill, and anal by methods of the Association of Official Agricultural Chemists (3). I The number of samples of a given species which were collected H, widely. Some species, such as little bluestem, are of widespread 0c rence throughout the entire area so that many samples were taken, ~' other species are of importance only at certain times of the year or. certain locations so that only a few samples were taken. For example, nual bluegrass (Poa annua) is an early spring grass and disappears -' ing summer and fall; salt grass or sacahuiste (Spartina spartinae) 0c only along the coast where the soils contain considerable salt. Berm (Cynodon dactylon), Dallis (Papsalum dilatatum), and carpet (Axon affinis) grasses occur usually on more fertile soils which have at cw time been under cultivation. The native grasses on virgin soil are la various beard grasses or bluestems, Indian grass, and Eastern 1:- grass. Big bluestem (And/ropogon p/rovincialis) is of great importance the better drained areas of virgin soils, while bushy beardgrass (Andr gon glomeratus) is of importance only on poorly drained soils. The s ~ of forage which may be growing on a given location are determined bl number of factors, and these factors may also affect, to some extent, chemical composition of the forage. COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 7 The grouping of samples of the same species 0n the basis of stage of growth, that is, whether young, in bloom, or mature, is sometimes diffi- cult. In some species, particularly the Papsalums, all three stages of growth can be found on the same plant at the same time. Some species, such as Bermuda and carpet grasses, may come into bloom and mature seed at any time during the growing season when weather conditions be- come unfavorable for vigorous growth. Other species, such as the Andrey)- ogons, come into bloom only once during the latter part of the growing season. Even with these species, considerable variation is possible, since the plant will be designated as young at any time between the first vigo- rous growth of the spring and the very slow growth in the latter part of the summer, when moisture and heat conditions over much of the region are so unfavorable that growth has practically stopped. An attempt has - been made to overcome this difficulty to some extent by separating the young growth into two groups, one, designated as young, collected in the spring, and the other, designated as medium, in the summer. A decision as to whether a given sample should be considered in the bloom stage or the mature stage is sometimes difficult, because there is a gradual grada- tion, and mature seeds may occur on one part of the plant while other parts of the plant are just coming into bloom. Grazing, burning, or mow- ing on the area selected may be such that very young plant material is secured throughout the growing season, regardless of the natural growth habit of the species. Soil samples were collected from all areas from which forage samples were secured several times. The samples were taken to a depth of about six inches, dried, passed through a 20-mesh sieve, and analyzed for total nitrogen and total phosphoric acid by the methods of the Association of Official Agricultural Chemists (3), and for active phosphoric acid and active lime (soluble in 0.2 N nitric acid). COMMON AND BOTANICAL NAMESHOF THE PLANTS The common names of many of the species collected, arranged in al- phabetical order, together with the botanical names as given by Cory and Parks (8), are given in Table 1. These are, in nearly all cases, the same as those used by Hitchcock (20). In many cases, the same species is known in different localities by different common names; for example, the common names of Spartina spartinae are salt grass, sacahuiste, or simply bunch grass. A single common name may also be applied to a number of species differing in botanical name. On the Gulf Coast, sacahuiste is Spartina spartinae, while in West Texas, it is Nolina teocana, which is not a grass. No attempt was made to separate a single species into different varieties of that species. When no common name is in general use for the species, only the botanical name is used in later tables. MOST IMPORTANT GRASSES ON THE PASTURES Most of the range land in the area is native pasture. The forage is chiefly various bluestem or beard grasses, as was the case in the East Texas Timber Country to the north (15). Little bluestem (Andropogon scoparius) is by far the most important, although big bluestem (Androp- ogon provincialis) is also of considerable importance. Indian grass (Sor- BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION Table 1. Common and botanical names of species sampled Common name ' Botanical name Alkali sacaton grass Angleton grass Bahia grass Beardgrass, annual Beardgrass, bushy Beardgrass, East Texas Beardgrass, silver Bermuda grass Bluegrass, annual Bluestem grass, big Bluestem grass, little Bristlegrass, green Bristlegrass, knotroot Broomsedge grass Black medick Buffalo grass/ Canary grass, Southern Canary grass, little Carpet grass Clover, bur Clover, white Cord grass Dallis grass Eastern gama grass Feather sage grass Fescue grass, slender Finger grass Foxtail grass Georgia grass Grama grass, hairy Grama grass, sideoats Grama grass, Texas Honeydew grass Indian grass Johnson grass Joint grass Knot grass Lespedeza Long-awned hair grass Longtom grass Love grass Maidencane Molasses grass, Needle grass Needle grass, Texas ‘Pull-and-be-damned grass Rabbitfoot gra s Rescue grass Sacahuiste Sage grass x Salt cedar grass Salt grass Salt water Bermuda grass Sand dropseed grass ' Spanish moss Spear grass Smut grass Switch grass Tanglehead grass Tickle grass Vasey grass Sporobalu: airoide: Androp ogon annulatu: Pzupalum notatum Polypogon monspeliensi: Andropogon glomeratu: Andropogon tener Andropogon Juccharoide: Cynodon dactylon Poa annua Andropogon provinciali: Andropogon Icopariu: Setaria viridi: Setaria lutescen: Amiropogon virginicu: Medicago lupulina Buchloe dactyloide: Phalari: caroliniana Phalari: minor Axonopu: a/fini: Medicago :pp. Trifolium nzpen: Spartina paien: Parpalum dilatatum Tripxacum dactyloide: Andropogon raccharoide: Fertuca octoflora Chlori: xpp. Setaria xpp. Paspalum plicatulum Bouteloua hirsuta Bouteloua curtijzendula Bouteloua rigidiseta Paxpalum plicatulum Sorghastrum nutam Sorghum halepeme Elyonuru: tripsacoide: Paxpalum dixtichum Lespedeza Jtriata Muhlenbergia capillaris Paspalum lividum Eragroxti: Jpp. Panicum hemitomon Melini: minutijlora Aristida spp. Stipa leucotricha Parpalum lividum Polypogon manspeliensi: Bromu: catharticu: Spartina xyartinae Andropogon spp. Monanthocloe littorali: Spartina Jpartinae Dirtichli: xpicata Sporobolu: cryptandru! Tillandxia umeoide: Stipa leucotricha Sporobolu: Poiretii Panicum virgatum Heteropogon contortu: Agrortis hiemali: Paxpalum uruillei ghastrum nutans), Eastern gama grass (Tripsacum dactyloides), and ail-E kali sacaton (Sporobolus airoides) often occur in the same areas,‘but sup-CL»; ply a very small part of the total forage. Various members of the Paspa-fi lum and Panicum genera, may provide considerable forage on limited’ 3i areas. Of these, Georgia or honeydew grass (Paspalum plicatulum), long- tom or pull-and-be-damned (Paspalum lividum), and switch grass (Pam'- COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 9 cum virgatum) are the most important. On other areas where local condi- tions affect the botanical population, other species are of importance. Smut grass (Sporobolus Poiretii) occurs in wooded areas along the north- ern edge of the region. Bushy beardgrass (And/ropogon glomeratus) and Florida paspalum grass (Paspalum floridanum) occur in low areas where Water tends to collect or drainloff slowly. Salt grass or sacahuiste (Spar- tlina spartinae), cord grass (Spartina patens), salt water Bermuda (Dis- t-ichlis spicata), and salt cedar grass (Monanthochloe littoralis) occur in limited areas along the coast, where considerable salt is present in the soil. Short grasses, such as buffalo (Buchloe dactyloides), grama grasses (Bou- teloua spp.), and crowfoot or finger grasses. (Chloris spp.), typical of the subhumid section of the state, occur in the western border of the region. Bermuda grass (Cynodon dactylon), Dallis grass (Paspalum dilatatum), and carpet grass (Axonopus affinis) frequently occur on land which has been under cultivation at one time, and along streams. The latter are the principal grasses being used in the region for pasture improvement (29). Some of the most important species of grasses in the region are the same as those which are most important in the East Texas Timber Coun- try (15). Carpet grass and some of the Paspalums (such as P. plicatu- lum, P. lividum, P. floridanum) are of considerably greater importance on the Gulf Coast Prairie than in the East Texas Timber Country. On the other hand, various Eragrostis species (particularly E. lugens) and some of the Paspalums (P. setaceum, P. pubiflorum, P. urvillei) and Panicums (P. anceps, P. capillare, P. capillioides, etc.), which were of importance on the sandy soils of the wooded areas of the East Texas Timber Country are not generally found on the Gulf Coast Prairie. Legumes do not grow well on most of the pastures of the Gulf Coast Prairie; hence, such le- gumes as lespedeza (Lespedeza striata) and bur clovers (Medicago spp.) are not as common on the Gulf Coast Prairie as in the East Texas Timber Country. Fertilization with superphosphate encourages the growth of le- gumes in this region as it does in East Texas. AVERAGE ANALYSES OF THE VARIOUS SPECIES OF FORAGE The highest, lowest and average analyses for protein, phosphoric acid and lime in different species and at different stages of maturity are shown in Table 2. The plants have been divided into four groups according to the stage of growth. The young stage of growth is that at which the grass is either just well started in the spring or in which the grass has been kept in a similar state through rather intensive grazing or mowing. The me- dium stage extends from the period when the rapid growth of the young grass has slackened, to the period when seed stalks begin to appear in significant quantity. The bloom stage extends througih the period of active blooming and seed formation. The mature stage covers that period after the seeds have matured and before new growth appears the following spring and, in general, includes those samples collected during the four or five winter months when the plant is relatively dormant. In some cases, where drought had induced dormancy in the fall, the samples have been included in the mature group. In many of the groups shown in Table 2, the number of samples of a given species at a certain stage of growth is so small that the averages are not satisfactory. \ \ Stage Number Protein Phosphoric acid Name of of growth samples Mean Low High Mean Low High Mean Agroxti: hiemali: (Tickle grass) Young 3 9.47 8.57 10.30 .54 .37 Agrosti: verticillata (Water bent grassy!‘ Young 2 8.63 8.21 9.04 .38 .32 Andopogon annulatu: Young 3 9.97 8.20 11.60 .53 .30 (Angleton grass) lBlloom 2 5.69 4.94 6.43 .34 .24 ature 1 4.39 . . . . . . .25 . . Andropogon glomeratu: Young 15 10.24 8.10 13.67 .42 .24 (Bushy beard grass) Medium 11 5.27 4.60 6.06 .19 .13 goom 5 4.45 5.45 .19 .13 ature 6 3.88 .3 4.59 .23 .11 Andropogon provinciali:* Young 32 9.32 4.83 13.00 .33 .16 (Big bluestem grass) Medium 12 5.03 4.54 6.34 .19 .14 gloom 6 4.24 4.9g .16 .10 ature 20 3.64 2. 6.7 . 3 .08 ‘Anrdropogon :accharoide.r* Young 9 8.92 6.05 12.47 .36 .26 N ' (Silver beard grass) ’ '_ Medium 1 “ “"5342 ” I‘ . . . . . .38 . . Moom . 4.24 6.63 .23 .19 atnre_..1-._5....-...___,,3. _fi___ 3.20 4.24 16 .15 Andropogon scopariusi‘ -10 . ‘fizz; 4,20,- . 12.55 :27’, .13 (Little bluestem grass) Medium. 8 38' _ 5.49 3.64 9.34 .20 .11 Bloom 23 4.45 2.93 6.25 .16 .07 Mature 33 3.37 2.50 4.86 12 .07 454......” tener* Young 4 9.09 8.58 9.28 T51 .20 Medium 1 5.19 . . . . . . .24 . . llaloom 1 5.1g . . . . . .1’; ature 7 3.6 .81 5.34 .1 . 5 Andropogon virginicufi Young 4 10.82 8.71 13.99 .44 .32 (Broomsedge) Medium 2 5.44 5.37 5.51 .33 .30 Ilélloom 1 3.7: . . . . . . .1211 . . . aturc 4 3.2 3.00 3.74 .1 .10 ‘ 4.7.7.71. 1.5.5.5987 Young s 6.78 5.15 8.27 .18 .17 (Needle grass) Mature 3 5.58 5.29 5.95 .18 16 Arixtida oligantha* Medium 1 4.85 . . . . . . .15 . . (Needle grass) Bloom 1 5.27 . . . . . .17 . . Axonapu: affini:* Young 51 7.19 4.40 10.15 .25 .16 (Carpet grass) Medium 20 5.80 4.17 7.43 2O 16 llelloom 10 5.3; 4.08 2.90 .12 .13 ature 2 4.0 3.98 .08 .1 .13 Bouteloua curtipendula oung 2 8.83 7.42 10.23 .30 .22 (Sideoats grama grass) Ilalogm 2 6.26 7.71 .23 a ure » . . . . . . . . . . Bouteloua hirsuta - ature 2 3.63 3.59 3.66 .11 .10 (Hairy grama grass) 3' Bauteloua rigidireta gYoung 2 7.68 7.10 8.25 .23 .21 (Texas grama grass) (Bloom 5 6.81 5.92 7.31 .21 .15 Bra(mu.r cathartficusi‘) ' Young 1 12.35 . . . . . . .37 . . Rescue g ass Buchloe dactyloidé: V. Young 6 8.65 7.42 9,93 .36 .22 (Buffalo grass) } Medium 3 6.74 5.75 7.43 ‘.31 .19 . *7 Bloom 5 7.34 4.99 9.41 .27 .22 . '\Mature 5 6.16 4.80 7.70 .25 .13 Chloris cucullata '\ 011118 1 13-26 - - - ~57 - (Black finger grass) 3113110911 1 . . .. ‘. . g a ure . . . . . . . . . Cynodon dagtylorfx‘ Young 22 .41 .24 (Bermuda, grass) Medium 5 7.09 5.90 8.84 .84 .25 {Iloom 8 7.41 4.85 10.33 .33 " ature 3 5.7 5.01 6. .24 . Dirtichli: 11:71am oung 4 7.37 - 6.39 8.58 .28 .24 (Salt water Bermuda grass) Mledium 2 5.6g 4.75 6.48 .17 oom 1 5.7 . . . . . . . . . Elyonuru: tripsacoide: Bloom 2 4.91 4.816 4.95 .22 .14 (Joint grass) Eragrorti: Ipectabili: Medium 3 4.56 4.20 4.83 .18 .12 (Purple 1ovegrass)* Mature 2 4.17 3.39 . Faxtuca octoflara oung 2 8.47 8. 9 . . . (Slender fescue grass) Heteropogon contortu: Young 2 8.85 8.25 9.45 .34 .31 (Tanglehead grass) Medium 2 6.95 6.38 7.52 .27 .19 llaloom 2 4.31 4.00 4.62 .14 ature 1 3.12 . . . . . . . .. Hordeum murinum (Sea. barley) Young 3 9.25 7.98 10.91 .48 .46 Lexpedeza striata (Lespedeza)* Young 4 19.95 13.20 23.00 .58 .38 10 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION of growth (percentages of dried grass) *Averages for the East Texas Timber Country are given in Bulletin 582. 3 Table 2. Protein, phosphoric acid, and lime content of different species of grasses at various ‘l u‘! =‘ . -..- -... . ;.-' '24-'32»- hbwcwewww- M“ *‘ "-0 “ "f > 2. COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 11 e 2. Protein, phosphoric acid, and lime content of different species of grasses at various stages of growth (percentages of dried grass) (Continued) Stage Number Protein Phosphoric acid Lime Name of of growth samples Mean Low High Mean Low High Mean Low High hirpida (Bur clover) Young 1 21.25 . . . . . . .66 . . . . 1.34 . . . . lupulina (Black medick) Bloom 1 15.50 . . . . . . .43 . . . . .78 . . . . inutiflora (Mol’ses grass) Young 1 13.64 . . . . .. .71 . . . . .64 .. . . loe litarali: Young 1 7.19 . .. . .. .24 .. .. .27 .. .. cedar grass) Medium 2 5.49 5.45 5.53 .16 .15 .17 .30 .15 .45 Bloom 2 5.69 5.68 5.70 .22 .21 .23 .30 .30 .30 gia capillari.r* Young 11 7.88 3.70 10.95 .26 .13 .56 .40 .29 .59 -awned hair grass) Medium 4 4.71 4.00 5.58 .17 .13 .18 .47 .44 .49 Bloom 3 4.15 3.86 4.69 .15 .13 .16 .37 .35 .41 Mature 2 3.84 3.62 4.02 .16 .13 .18 .52 .45 .59 pgpillarigidg_r* Young '7 8.81 7.01 12.16 . 3 .20 .60 .44 .34 .62 asciculatum Young 1 8.61 . . . . . . .33 . . . . .48 . . . . Bloom 1 5.89 . .. . . .17 .. .. .44 .. .. helleri* Young 1 9.30 . .. .. .21 . . . . .41 . . .. gmitgnlon (Maiden cane) Young 2 13 26 11.80 14.71 .43 .26 .59 .70 .37 1.02 Lindheinzeri* oung 10 8.97 7.21 11.48 .27 .17 .37 .74 .39 1.09 Mature 1 5.03 . .. . .. .12 .. . . .84 .. . . virgatum Young 14 9.04 5.55 11.98 .38 .22 .58 .55 .35 1.08 7 grass) Medium 3 4.59 3.92 5.50 .19 .15 .26 .45 .42 .51 Bloom 7 4.87 3.59 6.43 .21 .13 .33 .47 .23 .66 Mature 9 3.74 2.47 5.12 .19 .11 .45 .61 .34 .94 nlumum Bloom 1 6.31 . . . . . . . . . . 1.04 . . . . ‘dilatatum* Yfiung 23 11.752 7.65 22.15 .42 .22 .78 .68 .46 .96 grass) Medium 3 7.45 6.86 7.93 .46 .44 .48 .71 .54 .89 Bloom 10 6.67 4.87 8.36 .26 .19 .49 .58 .30 .78 MaiYfire 4 5:72 2.55 8.46 .38 .19 .54 .78 .47 1.28 g ixtichum (Knot grass)* Young 6 10.21 7.85 11.39 .48 .26 .76 .77 .42 1.05 _. laridanum* Young 3 10.25 8.37 13.04 .25 .17 .36 .64 .61 .67 " Medium 8 5.66 4.48 8.90 .18 .12 .27 .55 .43 .73 " Bloom 4 5.07 4.40 5.75 .22 .14 .33 .67 .42 .88 ‘ Mature 2 4.60 3.68 5.35 .14 .12 .16 .60 .58 .61 ' ~ wegianunz Young 7 9.93 7.30 14.51 .36 . 3 .54 .61 .36 .84 :3 Mature 2 3.38 3.25 3.51 .13 .12 ..14 .58 .53 .63 1n‘ Young 1 14.34 . .. . .. .44 . . . . .60 . . .. a m Young 7 9.49 7.10 12.64 .45 .24 .72 .71 .34 1.59 y ) Medium 13 6.26 4.45 7.13 .31 .17 .49 59 .32 1.30 ~ Bloom 5 4.64 3.77 6.00 .26 .15 .49 .54 40 .85 i, Mature 7 4.07 3.48 5.63 .18 .11 .40 .47 32 .88 ' .rtachyum* Bloom 2 6.70 6.27 7.13 .32 .29 135 94 .68 1.19 ‘um* Young 5 11.44 8.38 14.35 .41 .32 .51 .92 .61 1.38 . s) Mature 1 7.75 . .: . .. _.29 .. .. .56 .. .. ' tulum* Young 40 8.22 5.04 11.90 .28 .14 .41 .66 .42 1.08 grass) Medium 27 5.55 4.37 7.75 .21 .14 .41 .69 .39 1.10 Bloom 19 5.08 3.61 7.19 .18 .11 .36 .70 .43 1.26 Mature 21 4.13 2.55 5.71 .14 .08 .22 .68 .41 1.13 ucen * Mature 1 4.50 . . . . . . .16 . . . . .41 . . . . ' ‘flomm Mature .1 8.29 . . . . . .22 . . . . .63 . . . . ’ um* Young 3 10.85 9.18 12.38 .33 .30 .38 .81 p .78 .86 . ‘Z ‘ Medium 2 8.34 7.05 9.62 .28 .22 .33 .90 .85 .94 ' Mature 1 4.99 . . . . . . .13 .. . . .71 . . . . 7 - ineum* Young 6 10.53 8.85 11.71 .39 .31 .45 .69 .57 .80 ~- Bloom 1 7.47 . . . . . . .37 . . .90 . . . . 5* Young 5 8.58 7.90 9.56 .29 .18 .40 .76 .37 1.38 i s) Medium 1. 6.21 . .. . .. .26 . . . . .67 . . .. Bloom 7 5.85 4.11 7.86 .27 .15 .46 .65 .43 1.10 . ~ Mature 2 4.19 3.65 4.73 .17 .16 .18 .59 .41 .76 ' tum ' Young 1 21.16 . . . . . . .51 . . . . .42 . . . . 0t grass) ‘ ' ‘m: Young 3 9.08 8.30 10.35 .53 .42 .64 63 .43 .83 "I canary grass) . Young 3 9.36 9.04 9.72 .44 .33 .65 54 .45 .68 nary grass) ~ ‘ . Young 1 18.63 .81 .78 ' bluegrass) * ~- peliensi: Young 2 12.23 12.10 12.35 .69 .66 .71 .44 43' .45 beard grass) " -. Young 1 8.65 . . . . . . .36 .. . . .68 .. . . _ Bloom 2 5.15 4.30 5.99 .42 .14 .69 .59 .51 .67 ~ Mature 1 5.44 .18 .34 ‘i’: tail)* i Young 4 v 11.35 10.41 12.45 .47 .36 .62 .57 ,.52 .69 xtail)* : for the East Texas Timber Country are given in Bulletin’ 582. (continued) 12 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATIO Table 2. Protein, phosphoric acid, and lime content of different species of grasses’ at va of growth (percentages of dried grass) (Continued) 4 ’ i Stage Number Protein Phosphoric aci‘d _ . ; Name of of v growth samples Mean Low High Mean Low High Mean Sorghartrum nutan:* ' Young 16 10.02 6.35 12.92 .38 .18 .70 .68 ' (Indian grass) Medium 10 4.91 4.35 5.60 .16 .12 .22 .77 5 Bloom 3 5.02 3.73 6.07 .21 .19 .25 .45 i Mature 9 3.58 2.61 4.91 .15 .11 .23 .67 ~ < Sorghum halepen.re* Young 5 13.0.1 ,. 9.78 15.67 .65 .49 .96 1.16 (Johnson grass) Medium 4 7:11 6.69 7.82 .38 .30 .44; 1 i» x5 - "Eifilw 4' 6.55 i 5.31 8.06 .34 .26 .44 1.03 I .Mature 1 4.47 . . . . . . .19 . . . . 78 "'_ il Sparta. paten: Young s 8.47 4.5a 10.36 .31 .12 .46 a 1st n. 3 (C0111 grass) Medium 10 4.89 3.71 6.34 .20 .13 .29 .62 “ 1 Bloom 1 4.32 . . . . .16 . . .59 ‘ ' . Mature 4 4.35 3.22 5 91 .15 .09 26 .43 . Spartina Jpartinae Young 10 9.34 6.38 12 60 .33 .17 52 . ='_ i (Salt grass) Medium 5 5.05 4.08 7.61 .19 .14 .28 .66 _A '1 Bloom 6 5.66 5.12 6 20 22 .20 .23 .49 1., , ' v Mature 7 4.36 2.94 5 06 .16 .1.1 26 .50 f Spornbolu: airaide: Young 19 9.02 5.93 12 11 .32 .21 53 57 f? (Alkali sacaton) Medium 11 5.75 4.70 7 38 .21 .12 .34 60 v Bloom 8 6.55 4.45 9 41 .24 .20 27 .49 ‘._ Mature 5 5.00 3.55 7 09 17 .12 23 .27 ' . Spombolu: cryptandruxl‘ Young 1 10.00 . . . 25 .. .41 Sporobolu: Poiretii Young 20 9.04 6.38 11 38 31 .22 47 .50 __ (Smut grass) Medium 6 6.65 5.65 7 78 27 .19 39 .47 Bloom 11 6.83 5.24 8 90 .26 .18 35 50 ‘I, Mature 8 5.48 4.63 7.46 19 .14 28 59 31% leucotricha Young 9 9.80 8.20 13 30 34 .27 45 56 ., (Spear grass) Medium 2 6.17 5.33 7 00 .19 .17 22 54 ‘l i Tillandria 616.6711» _ 4 4.62 4.06 5 00 0s .07 09 51 < f (Spanish moss) " Trifolium repem‘ Young 1 19 86 . . .61 . . . 1 56 - (White clover)* . Triodia albncen: Young 1 9 35 . . . .42 80 1 ' (White triodia) I ‘ Tripsacum dactyloidex‘ Young 6 10.96 9.09 12.65 .46 .23 .63 .60 ~i (Eastern gama grass) Medium 7 5.37 4.31 6.39 .21 .16 .28 .64 ‘1 Bloom 1 7.09 . . . . . .30 . . . . .79 “ Mature 6 4.16 2.92 5.74 ..16 .11 .24 .64 -' Vicia Leavenworthii Young 1 18.54 . . . . . 47 . . . 1.05 *AverageS for the East Texas Timber Country are given in Bulletin 582. I, The analyses given in Table 2 and succeeding tables are stated: terms of protein (sometimes called crude protein, or the percentage of- trogen multiplied by'6.25), phosphoric acid (phosphorus pentoxide, P and lime (calcium oxide, CaO). The analyses given may be converted g terms of the element concerned by multiplying protein‘ by 0.16 for nitm» . (N), phosphoric acid by 0.4368 for phosphorus (P), and lime by 0.7147 calcium (Ca). - 4 The average, minimum, and maxium analyses given in Table-2 : marked variations among different kinds of plants and among sample)“ different stages of maturity of the same kind of plant. Little blu averaged 7.85% protein while Dallis grass averaged 11.48% protein. the young stage of growth. Corresponding averages for phosphoric p were .27% and .42%, and for lime, .57% and .68%. Differences am species were usually wider for protein and phosphoric acid than for y; Lower percentages of protein and phosphoric acid were found in -, plants, as compared with young plants, while percentages of lime in u A species did not change greatly. The relative differences with older --°j varied widely with different grasses. For example, protein in little stem averaged 7.85% in the young grass and 3.37% in the mature 1 COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 13 a relative difference of 57%, while the corresponding figures for buffalo grass were 8.65% and 6.16%, a relative difference of only 29%. Similar differences were observed with phosphoric acid; the averages for young and mature little bluestem were .27 % and .12%, a relative difference of 56%, and for buffalo grass, .36% and .25%, a relative difference of only 30%. In general, the tall, bunchy, native grasses, such as the bluestems or beardgrasses, contained lower percentages of protein and phosphoric acid than the short, fine-stemmed grasses, such as Bermuda and buffalo grasses, and the relative decreases in percentages as the plants advanced in maturity were greater in the tall grasses than in the short grasses. In order to show more clearly the differences among different species and stages of growth, the averages for the principal species given in Table 2 have been rearranged in Table 3 to compare the relative order with respect to protein, phosphoric acid and lime in samples of young and ma- ture grasses. In the young grasses, protein ranged from 11.53% in John- son grass to 7.19% in carpet grass, a relative difference of 38%; phos- phoric acid ranged from .59% in Johnson grass to .25% in carpet grass, a relative difference of 58%; lime ranged from 1.14% in Johnson grass to Table 3. Principal species of grasses arranged in order of their average protein. phosphoric acid and lime contents at young and mature stages of growth Young stage of growth Protein, % Phosphoric acid, % Lime, % Good Fair High Johnson 11.53 Johnson .59 Johnson 1.14 Dallis 11.52 Eastern gama .46 Good Bermuda 11.37 Dallis .42 Longtom .71 Eastern gama 10.96 Bushy beard .42 Dallis .68 Fair Bermuda .41 Indian .68 Bushy beard 10.24 Longtom .40 Bermuda .67 Indian 10.02 Buffalo .36 Georgia .66 Texas needle 9.80 Indian .38 Carpet .64 alt 9.34 Switch ' .38 Buffalo .60 Big bluestem 9.32 Silver beard .36 Eastern gama .60 Longtom 9.16 Texas needle .34 Bushy beard .59 Smut 9.04 Salt .33 Alkali sacaton .57 Switch 9.04 Big bluestem .33 Little bluestem .57 Alkali sacaton 9.02 Deficient Big bluestem .56 Silver beard 8.92 Alkali sacaton .32 Texas needle .56 Buffalo 8.65 Smut .31 Switch .55 Georgia 8.22 Georgia .28 Silver beard .53 Little bluestem 7.85 Little bluestem .27 Salt .51 Carpet 7.19 Carpet .25 Smut .50 Mature stage of growth Protein, % Phosphoric acid, % Lime, '70 Fair ~ Fair Good Buffalo 6.16 Dallis .38 Dallis .78 Deficient Deficient Georgia .68 Dallis 5.72 Buffalo .25 Indian .67 Bermuda 5.71 Bermuda .24 Eastern gama .64 Smut 5.48 Bushy beard .23 Buffalo .62 Alkali sacaton 5.00 Smut .19 Bermuda .61 Salt 4.36 Switch .19 Big bluestem .61 Eastern gama. 4.16 Longtom .18 Switch .61 Georgia 4.13 Alkali sacaton .17 Little bluestem .60 Longtom 4.07 Very deficient Smut .59 Carpet 4.03 Eastern gama .16 Silver beard .54 Bushy beard 3.88 .16 Carpet .52 Switch 3.74 Silver beard .16 Alkali sacaton .51 Silver beard 3.66 Indian .15 Salt .50 Big bluestem 3.64 Carpet .15 Longtom .47 Indian 3.58 Georgia .14 Fair Little bluestem 3.37 Big bluestem .13 Bushy beard .39 Little bluestem .12 /, 14 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION .50% in smut grass, a relative difference of 56%. At the mature stage of growth, the relative order of the grasses is considerably changed. Protein ranged from 6.16% in buffalo grass to 3.37% in little bluestem, a relative difference of 45%; phosphoric acid from .38% in Dallis grass to .12% in little bluestem, a relative difference of 50%. Only one mature sample of Johnson grass was collected. The data in Table 3 show the comparatively wide differences. in chemical composition among different species, the marked decrease in percentages of protein and phosphoric acid with ma- turity, and the different effects of maturity upon the relative composition of the different grasses. Of the 18 species of grasses whose average composition is shown in Table 3, Johnson grass, Dallis grass, and Bermuda grass were the highest and little bluestem and carpet grass were the lowest in protein and phos- phoric acid. At the young stage of growth, Johnson, Dallis, Bermuda, and Eastern gama grasses contained more than 10.5% protein and hence may be considered good grasses in this respect (see Table 5). All other species listed in Table 3 contained more than 6% protein, and hence contain fair percentages of protein, but both little bluestem and carpet grass contained less than 8% protein and are the lowest in the list. Johnson, Eastern gama, Dallis, bushy beard, and Bermuda grasses contained sufficient phos- phoric acid at the young stage of growth, while alkali sacaton, smut, Georgia, little bluestem, and carpet grasses contained less than .33% phosphoric acid, and hence are considered deficient in this constituent, even at the young stage of growth. At the mature stage of growth, buf- falo, Dallis, and Bermuda grasses contained more protein than the other species, but buffalo grass was the only species which was not deficient in protein. Dallis grass was the only species which was not deficient in phos- phoric acid. Little bluestem is at the bottom of the list in both protein and phosphoric acid. Carpet grass is intermediate in protein and near the bot- tom in phosphoric acid. ‘ AVERAGElFEED CONSTITUENTS IN THE VARIOUS SPECIES OF FORAGE The usual feed analyses were made on samples of most of the species of grasses collected; averages of these analyses are shown in Table 4. Averages for protein given in Table 4 are slightly different from those given in Table 2 because the averages given in Table 4 do not include all i of the samples whose averages are given in Table 2. However, the aver- ages in Table 4 show differences among different species and stages of , growth similar to those discussed in the preceding section. Ether extract . was low in all samples and it is doubtful if the differences between dif- . ferent species at the same stage of growth is significant; the decrease l with advancing maturity is in most cases small, but occurs regularly and is therefore probably significant. Crude fiber was lower in short grasses, * such as Bermuda and buffalo, usually running about 25%, than in the tall bunch grasses, which often contained more than 30% crude fiber. Crude fiber was usually lowest in young samples. In the later stages of growth, the differences among different grasses were usually quite small. Nitro- gen-free extract usually ranged from 40% to 45% in young grasses, and from 45% to 50% in mature grasses; differences among species were COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 15 Table 4. Average chemical composition of different grasses at various stages of growth (percentages of dried grass) Stage Number Pro- Crude N itro- Ash Name o of tein Fiber gen-free growth samples Extract Agrosti: hiemali: Young 1 10.30 30.99 40.93 7.81 7.91 (Tickle grass) Agroxti: verticillata Young 2 8.63 27.46 40.97 7.29 13.4 Andropogon glomeratru: Young 6 9.78 28.93 41.77 7.79 9.8 (Bushy beard grass) Mature 3 4.16 31.22 48.07 8.35 6.32 Andropogon prozwinciali: Young 6 8.76 29.41 41.96 7.74 9.54 (Big bluestem) Mature 2 4.95 25.06 50.36 7.15 10.99 Andropogon saccharoide: Young 2 7.63 28.42 41.27 8.78 12.48 (Silver beard grass) Medium 1 5.42 31.32 44.44 7.64 9.66 Bloom 3 5.29 32.09 44.32 7.24 9.46 ' Mature 2 L43 32.08 45.71 8.01 9.45 xlndropogon scopariu: oung 35 7.28 . 29.39 44.21 8.38 8.81 (Little bluestem) Medium 3 6.60 . 29.18 45.58 7.72 9.10 Bloom 2 4.76 . 33.27 44.21 7.54 8.52. ature 7 3.141 . 30.66 47.93 8.00 8.26 Anirorogofl Miner oung 2 8.97 . 26.98 44.54 7.73 9.28 Bloom 1 5.46 . 29.04 47.72 6.81 8.60 Mature ’ . 2 4.64 . 31.45 46.04 8.18 7.80 flndropogon virginicu: Young 2 12.49 . 28.55 39.79 7.33 10.14 Anlrtida Iongexpica Young 3 6.78 1.63 27.71 44.65 8.37 10.86 lVlature 2 5.62 2.27 32.02 45.22. 6.91 7.96 Arillldd oligantha Young 1 4.85 2.00 28.89 47.35 7.96 8.95 A4WMO1WI 4.570111‘ Younf! 8 7.20 1.47 27.04 46.62 8.39 9.28 (Carpet grass) Bloom 1 6.90 1.33 30.69 45.06 7.65 8.3 Bouteloua curtipefldula Young 1 10.23 2.01 26.17 44.02 7.57 10.00 (Sideoats grama) Mature 1 3.14 2.03 26.92 48.16 7.85 11.90 Boureloua rigidixeta Young l 7.78 1.73 28.69 41.45 8.06 12.29 (Texas grama) Bloom 3 6.64 1.61 27.02 41.20 7.34 16.19 Emma: catharticu! Young 1 12.35 1.99 26.77 31.47 7.24 20.18 (Rescue grass) " Buckles daclylvider Young 3 8.54 2.14 26.22 46.30 9.13 7.67 (Buffalo QPaSS) Bloom 4 6.86 1.53 25.68 47.70 7.63 10.60 ature 3 7.00 1.50 26.11 47.32 7.86 10.21 Cynodon dactylon oung >11 9.85 1.77 24.80 45.50 8.66 9.42 (Bermuda grass) Bloom 2 10.27 2.04 25.46 44.63 8.93 8.67 Mature 1 6.75 1.82 26.34 48.85 8.80 7.44 [Jistichlir spicata Young 4 7.37 1.58 28.43 48.86 7.72 8.01 (Salt water Bermuda) Bloom 1 5.75 1.61 22.21 54.16 8.02 8.25 Elyonuru: tripsacoide: Bloom 1 4.86 1.59 36.24 44.80 7.50 5.01 Festuca octo/lora Young 2 8.47 2.00 27.28 42.13 7.34 12.78 Heteropogon contortur Young 2 8.85 1.85 28.4! 43.49 8.18 9.16 (Tanglehead) Bloom 2 4.31 3.22 32.87 46.96 7.33 5.31 Mature 1 3.12 1.81 31.81 49.55 7.60 6.11 Hordsum murinum Young 1 10.01 2.05 27.57 41.00 7.69 11.68 Medicago hirpida Young 1 21.25 2.71 21.23 38.31 7.78 8.72 Medicago lupulina Bloom 1 15.50 2.67 22.92 41.90 7.33 9.68 Melini: lminutiflora Young 1 13.64 2.03 30.62 33.49 6.72 13.50 Mananthochlos littorali: Young 2 6.36 1.60 26.07 45.55 7.49 12.93 (Salt cedar grass) Bloom 2 '5.69 1.16 27.67 47.28 7.51 10.69 Muhlenbergia tapillari: Young 4 9.21 1.80 32.44 40.03 7.47 9.05 (Long-awned hair grass) Mature 1 3.62 1.57 34.34 46.00 7.62 6.85 Panicum helleri Young 1 9.30 2.24 26.97 42.42 8.17 10.90 Panicum hemitamon Young 1 11.80 1.93 25.86 41.81 6.94 11.66 Panicum Lindheimeri Young 4 9.60 2.30 25.76 40.85 7.24 14.25 Panicum virgatum Young 3 9.69 2.41 27.19 42.18 7.99 10.54 (Switch grass) Medium 1 3.92 1.43 33.29 47.99 7.32 6.05 ~ Bloom 3 5.04 1.59 30.91 49.64 6.98 5.84 Mature 4 3.49 1.70 29.37 50.03 8.25 7.16 Parpalum almum Bloom 1 6.31 2.01 28.43 47.54 7.44 8.27 Pupalum dilatatum YBung 9 9.24 2.23 28.88 40.78 9.44 9.43 (Dallis grass) Bloom 1 6.45 2.18 29.14 44.13 9.31 8.79 Mature 1 7.34 2.02 31.19 41.65 7.63 10.16 Paxpalum dixtichum Young 2 9.57 2.04 27.19 41.74 7.29 12.17 Parpalum floridanum Medium 3 5.52 1.47 31.66 43.81 8.56 8.98 Bloom 1 4.92 1.83 31.85 44.91 8.81 7.68 Mature 2 4.60 1.44 29.71 46.88 8.48 8.89 Paxpalum Hartwegianum Young 2 11.52 2.35 24.59 42.55 7.70 11.29 Mature 2 3.38 1.27 32.29 46.59 8.61 7.86 Parpalum Langei Young 1 14.34 2.59 24.87 34.96 10.85 12.39 Pupalum lividum Young 3 6.82 1.69 26.49 47.70 , 7.66 9.64 (Longtom) Medium 1 5.41 1.21 30.76 46.72 7.31 8.59 Bloom 4 4.73 1.62 27.65 47.83 8.00 10.17 Mature 4 3.67 1.28 28.42 50.24 8.23 8.16 Paxpalum notatum Mature 1 7.75 1.88 28.20 43.49 7.98 10.70 (continued) 16 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION Table 4. Average chemical composition of different grasses at various stages of growth (percentages of dried grass) (Continued) Stage Number Pro- Ether Crude Nitro- Water Ash Name of f o tein Ex- Fiber gen-free growth samples tract Extract Parpalum plicatulum Young 5 8.97 1.95 26.33 44.12 8.03 10.60 (Georgia grass) Medium 1 5.55 1.74 29.17 47.70 7.51 8.33 Bloom 6 5.76 1.56 29.25 45.91 8.12 9.40 Mature 9 4.32 1.75 29.91 47.27 8.31 8.44 - Paspalum pubescen: Mature 1 4.50 1.32 32 72 44.86 8 18 8.42 Paspalum pubiflorum Mature 1 8.29 1.42 28 86 40.00 8 15 13.28 Pdrpalum Ieiawum Young 1 11.00 1.92 23 55 38.97 8 22 16.34 ‘ Medium 1 7.05 1.78 30 44 43.93 7 31 9 49 Paffifllum Iimmifleum Young 5 10.30 1.99 28 58 38.77 7 88 1° 48 Paxpalum urvillei Young 3 8.52 1.90 29 37 40.80 8 41 11 00 (Vasey grass) Bloom 4 6.29 1.93 s6 1s 29.29 7 39 9 02 Phalari: carolinicu: Young 3 9.08 2.11 25 99 38.42 8 71 15.69 Phfllflrif minor Young 2 9.19 2.22 23 62 38.11 7 69 19.17 Polypogon monspelienri: Young 1 12.35 2.52 25 94 36.91 8 85 13.43 541541131 luiflrflflfll‘ Mature 1 5.44 1.65 31 96 44.64 7 54 8.77 Sorghum halepenre Young 1 9.78 2.75 31 26 39.11 6 36 10.74 (Johnson grass) Medium s 7.24 2.09 29 09 49.76 s 21 9.61 Bloom 2 6.69 1.92 30 48 44.38 7 99 8.55 Sorghaxtrum nutan: Young 6 10.49 2.02 28 11 40.45 7 86 11.07 (Indian grass) Bloom 1 5.2.6 3.08 32 as 45.26 6 42 7.65 Mature 4 3.44 1.71 31 07 46.37 8 04 9.37 Spartina paten: Young 2 10.21 2.15 29 35 39.91 7 91 10.41 (Cord grass) Medium 3 4.81 2.14 30 90 46.13 7 46 8.56 Mature 4 4.35 2.17 30 38 47.53 8 32 7.25 Spartina Ipartinate Young 4 10.17 2.34 29 35 40.49 8 40 9.25 (Salt grass) Bloom 4 5.85 2.31 30 93 44.15 8 60 8.16 ~ Mature 4 4.05 1.84 32 74 44.53 10 15 6.69 Sporobolu: airoide: Young 2 11.47 2.43 27 87 41.11 7 75 9.37 (Alkali sacaton) Bloom 3 7.20 1.77 31 92 43.05 6 68 9.38 Sporobolu: Poiretii Mature 4 5.16 1.70 32 30 46.20 7 95 6.69 (Smut grass) Medium 1 7.27 1.49 30 35 47.79 6 49 6.61 - Bloom 7 6.97 1.71 29 38 46.29 7 83 7.82 ’ Mature 5 5.71 1.55 28 93 46.74 9 10 7.97 Stipa leucotricha Young 5 8.73 2.12 28 80 41.28 8 05 11.02 Triodia albercen: Young 1 9.35 1.71 28 14 44.83 7 32 8.65 Tripsacum dactyloide: Young 5 11.06 1.98 26 77 41.24 8 12 10.83 (Gama grass) Medium 3 5.77 1.89 28 90 47.99 6 90 8.55 Bloom 1 7.09 1.89 27 44 46.55 7 20 9.83 Mature 2 4.73 1.80 27 92 47.58 8.33 9.64 Tillamisia umeoide: — 2 4.49 2.04 30 80 49.10 8.34 8.23 (Spanish moss) small and of doubtful significance. Water analyses averaged about 8% after the samples had been dried in the usual procedure, that is, at about 45°C. in a ventilated oven. This average of 8% is sufficiently accurate in most cases for use in converting analyses given in the various tables to a moisture-free basis where this is desired. Ash analyses ran approximately from 8% to 10%, although in some samples it was higher; ash contains not only the minerals taken up by the plants, but also the residue from soil or dust which has collected on them. GRADES OF CONSTITUENTS OF FORAGE In order to facilitate comparison of the composition of the samples, they are grouped into 5 grades or classes (Table 5), as was done in a previous publication (15). The groups have been arranged to carry as much meaning as possible and the limits of the grades were decided upon after careful consideration of a large amount of experimental work re- ported in the literature. The limits of grades used in Table 5 are based upon the requirements of beef animals on the range. The quantity of a given constituent utilized by an animal depends upon the percentage of that constituent in the feed, the quantity of feed -COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 17 Table 5. Grades for percentages of protein, phosphorus and calcium in forage for range animals Grade Crude Protein Protein 1 High 15.00 or more 2 Good 10.50 to 14.99 3 Fair / 6.00 to 10.49 4 Deficient 3.00 t0 5.99 5 Very deficient 0 t0 2.99 Phosphorus P P205 1 High .45 or more 1.01 or more 2 Good .30 to .44 .67 t0 1.00 3 Ifair .15 to .29 .33 to .66 4 Deficient .08 to .14 .17 to .32 5 Very deficient 0 to .07 0 to .16 Calcium Ca CaO 1 High .61 or more .83 or more 2 Good .31 to .60 .43 to .82 3 Fair .16 to .30 .22 to .42 4 Deficient .08 to .15 .11 to .21 5 Very deficient 0 to .07 0 ‘to .10 consumed, and the utilization of the constituent by the animal (2, 12, 22, 25). These factors are interrelated, and the percentage of one constituent may affect the utilization of another constituent. a The relative utilization of a constituent is related to some extent ‘t0 the percentage of that or other constituents in the ration. For example, according to data given by Morrison (25) and Fraps (12), when forage contains much less than 12% protein, only about 56% is digested; when the forage contains more than 12% protein, about 75% is digested. On the other hand, Archibald and Bennett (1) found that dairy heifers on a low- phosphorus ration utilized a higher percentage of the phosphorus than did heifers on a high-phosphorus ration, although the low-phosphorus ration was deficient in phosphorus and the animals were not as good as those on the high phosphorus ration. Beeson and others (5) found that feed was not utilized as well on a low-phosphorus ration as on a normal ration; steer calves required 30% more feed deficient in phosphorus to make a pound of growth, and gained 37% slower than calves on a ration contain- ing sufficient phosphorus. Feeds high in crude fiber are usually less di- gestible than those low in crude fiber. The requirements of animals as estimated by different investigators are not the same. Mitchell and McClure (24) estimate that the quantity of calcium required by fattening steers ranges from 24.7 grams per day for a 300 pound steer to 14.0 grams for a 1,000 pound steer; the percentages required in the ration range from .48% to .17% calcium (equivalent to from .67% to .24% lime). Weber and others (36) estimated that fatten- ing calves required more than 11 grams of calcium per day. Theiler, Green, and DeToit (32) found that 4.99 grams of calcium per day was not enough for cattle. Lindsey, Archibald, and Nelson (23) found that an average daily intake of 5.97 grams of calcium per 100 pounds of live weight resulted in normal growth and development, and that equally satis- factory growth was secured with 3.17 grams, although there was a con- siderably lower storage of calcium. ‘ The estimated requirements for phosphorus also vary, but not as Widely as in the case of calcium. Beeson and others (5) claim that the 18 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION phosphorus requirement for fattening beef steers was met by a phosphorus percentage in the ration of .18% (.41% phosphoric acid), while a deficiency of phosphoric acid was apparent in calves which received a ration con- taining .15 phosphorus (.34% phosphoric acid). Henderson and Weakley (19) estimate that the ration for dairy animals should exceed .20% phos- phorus (.46% phosphoric acid). Mitchell and McClure estimate that the phosphorus in rations necessary for fattening beef steers ranges from .34% for a 300 pound steer to .18% for a 1,000 pound steer (.78% to .41% phosphoric acid). Black and others (7) have found a phosphorus content of .13% (.30% phosphoric acid) and a calcium’content of .23% (.32% lime) as the minimum amounts of these elements required for Texas range cattle. A study of the available literature concerning the phosphorus content of forage from areas which were known to produce forage deficient in phosphorus, as compared with areas on which the cattle showed no evi- dence of phosphorus deficiency, showed that grass samples from deficient areas contained an average of .082% phosphorus (.19% phosphoric acid), while those from normal areas contained an average of .170% phosphorus (.39% phosphoric acid). Of 53 samples of forage reported from South Africa by Theiler (33) from a deficient area, 31 samples contained less than .17 % phsophoric acid, and 48 contained less than .33%. Of 81 samples reported from Florida by Becker, Neal, and Shealy (4), 14 samples from ranges producing healthy animals averaged .167% phosphorus (.38% phosphoric acid), while, 67 samples from deficient areas averaged .103% phosphorus (.24% phosphoric acid). Of 51 samples of prairie hay from a deficient area in Minnesota reported by Eckles, Gullickson, and Palmer (11), 44 contained less than .33% phosphoric acid. Of 54 samples from Montana reported by Scott (27), samples from normal areas averaged considerably more than .33% phosphoric acid while those from deficient areas averaged considerably less. Spring samples of grass in Utah, re- ported by Stoddart and Greaves (30), averaged .283% phosphorus and fall samples averaged .185% (.65% and .43% phosphoric acid); none of these samples was considered to be deficient in phosphorus. The limits of the grades shown in Table 5 thus have considerable meaning. DISTRIBUTION OF SAMPLES ACCORDING TO GRADES OF CONSTITUENTS The distribution of the samples with respect to different grades of protein, phosphoric acid and lime is shown in Table 6. Protein was very g deficient (Grade 5) in only 31 of the total of 1140 samples (3% of the total), but was deficient (Grade 4) in 479 samples (42% of the total). Phosphoric acid was very deficient (Grade 5) in 245 samples (21% of the total), and deficient (Grade 4) in 605 samples (53%). Lime was very de- ficient (Grade 5) in no samples, deficient (Grade 4) in only 5 samples, and fair in 199 samples (17% of total). None of the samples was high in phosphoric acid.and only 16 were high in protein, of which 7 were legumes. The distribution of the samples of a given species in the different ‘ grades varied widely with the different species. Protein was deficient in 13% of the samples of Bermuda grass and in 55% of the samples of little bluestem. Phosphoric acid was very deficient in none of the Bermuda 19 COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE HwouHHHH-fioov H H H H N N QHHHHNS v m m m N w oH EH55 H NH v vH m 3 oH oN HHHHHHHHHWQH Amwdnw HQQHMOV H. 3 H. H 3 H H HH. H Hm was; HuiH“ Havsfiw H H H H EooHmH Hmnwnw oTHHwHnHV H H H H MFDOW QHHHHHQMHHQ QHNHHMEW N H N H m w QSGHH Hmfizw oHHHowH/Hv H N w N H m MHHHHOW QHTEMHHQH Qflmwawkw . N H m m a 9HHHHEH>H H H H H E35 H H H H H H m m E582 Hwwwwm s23: w m H N N w MHHHHOW nauwnmyma HNOMQQONEQ‘ m w N m m N v U-HHHHHWS H H H H HHHooHmH H H H H HHHHHHHEHH H m. N N w w MHHHHOW 3:3 HSHHHQNQHHHHHHH w NN v H Nm mN oH mm HZHHHQE m wH w w mH H mH m. MN FHooHHH . . ‘ w Hm H N mN v , w 3 mm EHHHHHwHHH HHHHwumwHHHHH wHHLHwC w 3 wH H wN vv w HH mv mN 2H wHHHHoW Hatfirvfi Hawssvéw m. N N m m m wHHHHHHHHHH H w m w N w w EH65 . H H H H EHHHHEE AmmwHm HHHnoHH HoZHmV w m w m N H. m M5507 Huxokucuuw» HNQMQQQNEE‘ m wH m m vH N HH v oN QHHSwHH H m N w w w E85 . m w N oH m H NH mH HHHHHHHHHWE AHhmpmwHHHHH MHMHV H S“ m 3 HH H w Ha Hm MHHHHQW aHaéHaEH §H2HEEH~ H H w H H N w v v QHHHHHNHH H H m m N m m 63E w H H: H w N H H: HH EBHaHH Hmfizu Hzfin Hswsmv NH H" H HH m m 3 mH wEHSH §HE§°HH =§ézHéw H H H H wHHHHHwHH N H H H H N 88E H H H H H H H H N m wHHH-o? Amwauw HHOHQHMHQQ HJGQHQEHHu aowmmoxwt‘ N H H N N MHHHHQW aHuHHHuHHIwa HHFHPHMQ 6.83M oHHHoHHV m. H N m m M530? hm~wswwi HHHHQNMY 95E Ho Qv um. “v2. QHHNN. H. 2H “H. 3. H. 2. $2. v.55 Ho Ha. 23H Qvfiwi @136 QQEWN =53. l2. IImN. I|HH. l5. l3. IvH. |c $3.2 .153 I25 1......» I: H N m w N m w m H N m w m uHHoHu ecu? moHnH-Hnm HHHBQHM E2» 23H» 130w H630 Auow “Ho t. HHuHmH HHocU HHHHH 150D HHocU bah HHHQQ 93> HHNHHH HXHQU huh $5 huo> uoHHHH-HHZ Qufim 023M oEHH 2.5a Eu: uHHcHHnmo-TH QHZPHM GHQ-cum QHQBHHmuGOQw mfififiunwflwl-HOU HQ 055k." JQQQ E 31:32- HO uouaun mflQmhfl> uaéommcuu HO nomuonm HHHOBOWHmU MO DQTHESU HO QMODEBZ. n6 01-6? 20 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION Hguflfifleuv H H H H MHHSOW wfie~x~gaam§ 3:302 H H H H 082m 0:20.04 0080103 H H H H H M55? 0003.3 00000103 v H w v w MHHHHQW 00mm»: 00000003 £2.30 800 H N M M M MHHHHO» QNSHNMLSHNN HNNSQNLQNN H H H H 005002 N N N N 802m H H 0 H H N N E0502 H0005 1000200090 N H H N N MHHHHPW 0:200:00 aomum00fivm N H H N N NHHHHQW 0.51030 uuafiuk N N N N 005002 $000M 0>2 0HHHHHHAHV m. N H m m Eimmuws 0.310500%... HNNHONM§NN H0020 0503 H H H H N N 502m 003000.30.“ HQPNRHNQRHW H H H H 502m H H N H H N EHHHH00H>H $000M 01HHHFH0m H0003 v v v w MHHHHOW wHdwv 0000.25. HHHHHFSMNQ m m N H m 005002 w. v 0 m m w 502m H H. N N H. H m E3002 H0320 000E000 H. 0H N NH m N 0 NH NN mcHHoN 0.4.8000 =£§§0 H H H H 0.3502 v H . H H H 802m 6000mm 000:5 0H00Hmv H H H H MHHHHEH 003N038 0.0803 0 H 0 H 0 N 0 005002 H H. H w 0 N m 502m N H H N N H N 8.5.02 H320 swfismv 0 H. N 0 0 055W 3H00Ha8§ 2.00am H0000M 0HH000mv H H H H MHHHHQW 0000000500 3.52m m H m. H m H H» 502m 3000M 0500M 0005M; H N N H N H m 055% 0000.00.00.00 000N355 H0000w 0500M 0200C H w N N N Q-HHHPNE QQSHNMHH QSQHMHSQQ H H H H 000005 H H N N N 502m $000M 0500.0 00000118 N H H N N MHHHHOW 501200.358 wafifiaom 000E .H0 N. Nw. 00:. Q0 NN. 0H. 00H 0.00. 0.0 N». 00:. 000E .H0 0000.3 0000.3 0H. 00.0 QHLEN Q50. ||m1 INN. ||HH. I3. INN. |..._H. |0 00 00.2 13.3 I006 I005 l: H N m H. , N m 0 m . H N 0 0 0 _ 0:20 0:20 003500 HHHkopu 0:20 , 0:20 -C01 0:20 -H..H01 0.. “H0 202m 1000 .HH0~H |H~H0m 100w .HH0r.H Hwom 50> HHMHHH 1000 20m -H..H0m 50> HQQEHHZ 005m 0100M 0EHH 0030 1H00 0H.H0:n00:m 0100.0 HHHfiPHm . H10HHHHHHHH0OV 02033350 m0 0100M £000 E 0012505 m0 000000 0:25; 00 0000000 m0 003000 QGPHQMMHHH m0 003500 H0 0.8.1052 6 050a. 21 COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE HHBHHHHHHHHQS H H. H H QHHHHNS HwwwHw wHHHamC m N m N m N m M9507 EHHHQHQ: Htfiwfiwm H H H H N N 802m QNSRQQQQHQHNOH? HHNSHNQHQAN H N w H H m. H. v QHHHHQHHH H m H H m H H w w. EH65 N w N w H. N w NH HHHHHHwwHHH HEoHmHHowC H m H N m N N m. H. MHHHHQW HHSHHHENH iaHHRbi H H H H M250? Huucwfl SSHQRHQHN N N N N QHHHHQHHH H m H w m N m H. wHHHHoM, HHSESMQSHNQHH HaaHSHhum N N N N wHHHHmHHHH H N H H N H w w 502m w. m m N w w EHHHHHQHHHH m H N H N m MHHHHOM. Htsawwiefi. SQHHQHHQHH m N H H N m N w w MNHHHQV 553mm. fiaHufiénH H m. m H N H H w QMHHPGE m H o H m H o H E85 H m m m w EHHHHEHHHH HmwmHw wHHHwQV m cN H m H w N H H o H mN MHHDQW atauHeHww =§H3rém H H H H HHHOOHN 535w HHSHHQFEHH H w N H , N w N. N m QHHHHNHHHH w m H m m N m N 802m N H N H m N EHHHHzHH 322w HHSEQ H m w c H w w w N w H MHHHHOW SSwQMkmR 53.3%.» H H H H QHHHHNE w m H N w N w o H MFHHOW NNQEHEHRHNHH HkwHuwiwk H H H H E35 NNNHHSH =§§§m H H H H N N MHHHHOW tefioNwHkuHH Hfiduwiwk H H H H EH55 H H H H MHHHHOW §3u§~8umuw§% afifififim m w m w H w H. M550? nuwmafwHHfiHuu Safiawm N H H N N 0.2562 m. m m m E85 w m H w w HHHHHHHBHA Hmmdaw bu: wvwflkrdnwinvfimw N N N H. N, H N H HH 9E8» HIQHHRQQ QESQSHHaE N N N N EooHmH H H H H N N E332 322w .5?» swmv H H H H MHHHHOW 548x63: QQHHHQSHHHSHNQE 98E .5 HNNN. $3. 9H. NN. w.» 00H H. 3. H. NM. $3. 20E ac Qizwfi $21: £136 QLXWN Hi5. l3. |mN. .|HH. lib. l3. lvH. l. . evcHfimH i=3: I21. is...» l. H a m w N m w m H u m w m Hi3» QGGHO mQHQEdn NHHRPHM 33H» ti» $2. HHS? 5H2» . u. a. HHMHHH H250 huh 62H H250 bah HHQG .H.Ho> swim HSoU HHah AHoHH .33» HvH-EHHZ ~35 2.3a oEHA OUBMN Eva UmHQJQm-ufinfi 2.95 Hnmwuéhnm BH-osuflmico we 2.2m Juno H: 52.5.8 u: 13.8. use?!» u: 8:33 we uwHuoH-m unououumw we no-Qian we Bani-HZ 6 2.1a 22 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION §==Ess H N N N N H v m EEHEHZ Amwwpw fidmv N m w w v n v 0H MHHHHOV ‘$2252.. irxiwmm H m H m v v 055mg H H H H 502m N m N H v m H a o H E5252 Hmmwum 950v N m N N H v H m MGHHOW .33: gwvfimm H H H H wnfiumz v N N m H v 5002M v w H v v EEHESH Hnmwum ngcsoa m N m H m H m M250? uanumuHux 5:43am N v N v v N m UHHHQNS N H m H N m 502m m v m v 3 2 BEBE $85 =23: m m H H v w H m w H MES? qxfia: Evtviafom AHHSNOH noun»! v v v v Mnzofi .430; fitfiuw H . H H H vufiums 33.132 333$. N H H N N 502m HmnanwoHwmrfi uoopaocvC H H H H M050? ‘$232.84 a133,. N H H N N MGSQW azfim~6§h§oim §MQNAHQN H H H H NHHHHOW 33:: wok m w m m MGHHOW .55.: b.1821 H N a n m MHZ-OW ueiafiofiu QSHEPH H H H H M2507 Eiwnmmua SaHwfi-em H H H H N N . 0.05m N m N v H m v v 502$ H H H H EBHVwHH Hwmduu zwwsrv H m H N m m m M0507 E33»: 551.3% H H H H 502m . o m H Q m w MGHHOW Eauzmfiux»... §a~amwuk H H H H cnnusvm N H H N N E382 H N H N N H m MCHHON 5:333. SaHQNnuM H H H H H H N vnnfiwfi 383$.“ 5:15am N wH H m. m H oN H HN 0.25mi v m H H H H v N vH 3 802m w oN H H NH v w H N vN E5262 Hmmanw dmwncom! v om. m m H m H m Hm v ov M050? Eafiauflam SaHvmwum Ho:- no ovum. $2. QQNN. o.» 21H av 3. av Nm. $3. 0.35 u: ovaavH evmvdH $.36 evmad v.2. .12.. l3. .l.HH. |vw. la». ||vH. ll: 26H |l6méH I22. I22? l. H N n v N n v m H N n v m “no? “no? moi-cam fikeuu swim U Hi2» “:30 $3. “:20 Anew u: Ho Q60 kmfivm um 0 O6 . Hmfl l. b N | 3.5km oEHwH u Q H. mvvvwauu wmnnmu ow-AH-w-oanwo-HH o> i. HHH v.26 uHanH won huo> uOnEH-Z 38m 203M 533k 21:53:08 uafio-Sflncco u: oH-F-u JUNO E 515:5 no 3&3. @5223 “a mama-in u: nomuuqn aiououflw mo uoHnn-un we wuonuunZ d 03am. COMPOSITION OF FORAGE GRASSES FROIVI GULF COAST PRAIRIE 23 SH mwH. 2: m mH mH.N mow 3N wH woH wow m5“ Hw 3S Q4808 2 wNH NH“ H o H. fi wNH o o HHH m: wN wwH waswg wN wNH HH» H N Hm HHH Hm w w oH. mHH HH wwH 802m 3 wmH H_N N H wN 3H 3 w w ww 2H H NNN 531mg 3 Hww aw H NH 2N 2N NH 2 H6 m3 ww o mm... Mano? _ moHQEam :4 .H H H H M250? HHHHHSSHSQQQH F8?» H m N v m H w 25x2 . H H H H EooHmH / H w w H H w H. EHHHHXGHH Hmmwnm didw flnwuwmmC H w H m H w H w 950% §....Hs§.. §=QS§§B H H H H NHHHHOW nzwuqwfie QQQYB H H H H MGBON Bum»; Safiofiifi Hwmofi Jflfimnmw An... .m Q V V 111 HNWMQMQHQH Rmu-EHHHQFNE H H N H H N E5302 Hmwdnwlwwwc maxmHv m m w N H. m MHZ-OW EHuvSeQaQH umfim H w N w N N w w QHHGQE H. w w w oH H HH 862m H» N H m m H w 8:262 Hwzzw Hwfiww H.H m v .2 H. m: 3 wcsow $2.5m §H§P§Hw N w . N m H v m Qhsfia w N w m w w 8.65 . . H w N H H. w w w HH 55:52 Hcoumowm =§=S H 5 w H. NH v wH H 3 9E8» HQHEQ 322:3 w. H. N m w H H. 0H5HQH>H H. N w N H. w EQoHMH 93E .3 w.» 2. 9H. Nw. QH» NN. DEE; “Haw. QHNw. $2. v.3:- uc @534; QH.$.2 @135 QHQ 2.“ u“ wv l2. ‘MN. IIHH. .|H.w. l3. nlH.H. l. QH. 36H l3? I22. J22“ lc H N m. q N a H. m H a w H. m Hiomu “=30 moHnEmm H-QHFPHM in»? i3? Awuw 28H“. ‘flow no we sui H390 bah awn _ H250 bah AHQQ 95> AMHHH 1on0 ham é»: .33? “$5.2 Qufim 2.2a oEHA 2.3m Eva amusing-TH 2.2a imouofm AH-oscflconi mfihQIuHuu-HOO we 3.3a sumo E mumfliai no 393m @535; Ha nvnmauu u: @2925 aiououfiw u: moi-Ea» m: EoaEFZ .w 05am. 24 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION grass samples and 31% of the little bluestem samples. In general, much larger proportions of the samples of the tall grasses than of short grasses were deficient or very deficient in protein and phosphoric acid. The distribution of the samples of each species at different stages of growth is also shown in Table 6. The portion of the samples of the species containing percentages of protein and phosphoric acid in the lower grades is greater with older plants. At the young stage of growth, pro- tein was very deficient (Grade 5) in none of the samples, and deficient (Grade 4) in only 12%, while at the mature stage of growth, protein was very deficient in 14% and deficient in 78% of the samples. For samples at young, medium, bloom, and mature stages of growth, the percentages of samples which were deficient in protein were 8, 69, 60, and 93, respect- ively; for phosphoric acid, the percentages were 59, 89, 82, and 96. The effect of the stage of growth varied with the different species. Of 340 samples of 12 species of tall grasses at medium, bloom, and mature stages of growth, 94% were deficient (Grades 5 and 4) in protein and 96% de- ficient in phosphoric acid. Of 86 samples of 5 species of short grasses, 40% were deficient in protein and 76% deficient in phosphoric acid. Of these samples, protein was very deficient (Grade 5 only) in 8% of the .tall grasses and in none of the short grasses, and phosphoric acid was very deficient in 48% of the tall grasses and in only 13% of the short grasses. The figures in Table 6 show that many of the samples were deficient in protein, most of them were deficient in phosphoric acid and very few were deficient in lime; advancing maturity increased the proportion of samples deficient in protein and phosphoric acid, and different species varied widely in the proportion of samples in the different grades. THE CHEMICAL COMPOSITION OF THE SOILS Chemical analyses of 68 soils from which forage was collected were made in order to study the relation between the chemical composition of the soils and that of the grasses grown on those soils. A knowledge of this relation might enable one to predict the probable relative composition of forage from soil types whose general average chemical composition is already known and to apply knowledge already available concerning the chemical composition of a large number of Texas soils (13). Averages for the principal constituents concerned in this study in the samples of the six principal groups of soils of the region are given in Table .7. The distribution of the samples in different grades or levels of the different constituents is also shown in that table. The grades shown are the same as those previously proposed and discussed by the authors (15). However, since most of the soils were low in phosphoric acid, the grades for phosphoric acid have been divided into two sections in order to show a greater differentiation among the samples. Nitrogen was probably deficient in only one of the 68- soils. Total phosphoric acid was deficient (below .051%) in 58 of the soils, of which 13 were very deficient (below .0267. ). Active phosphoric acid was deficient (below 100 parts per million) - T in 62 of the 68 soils; of these, 47 were very deficient (below 31 p.p.m.); Active lime was relatively low in 15 samples, although only 3 of them i, COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 25 Table 7. Number of samples of soils in different grades of constituents. i Harris Hockley Edna Lake Lake Allu- Total Iv soils Katy soils Charles Charles vial soils light heavy soils soils soils number of soils 4 l0 19 1O 22 3 68 en, average, ‘.2 .160 106 127 .127 .157 .176 Grade 4, .031-—.060% ' 0 0 0 0 0 1 1 Grade 3 , .061—.120% 2 8 9 4 5 O 28 Grade 2, .121 180170 1 2 7 6 9 0 25 _ Grade 1, .181 A; or more 1 0 3 0 8 2 14 phosphoric acid, average, % .056 .029 .029 .032 .046 .103 Grade 5, (}—.025% 0 3 7 1 2 0 13 Grade 4, .O26——.035% 1 6 8 6 5 0 26 Grade 4, .036—.050% 1 1 4 3 10 0 19 Grade 3, 2, 1, .051"/¢. or more 2 0 0 0 5 3 10 phosphoric acid, average, p.p.m. 111 22 22 3O 57 275 , Grade 5, 0—1s p.p.m 0 2 s 2 10 0 22 ‘ Grade 5, 19—-30 p.p.m. 0 7 9 4 5 0 25 Grade 4, 31——64 p.p.m 1 1 2' 3 4 0 11 _ Grade 4, 65—100 p.p.m. 1 0 0 1 1 1 4 ~ Grade 3, 2, 1, 101 p.p.m or more 2 0 0 0 2 2 6 A lime, average, p.p.m 3675 1753 3069 3227 7245 17119 Grade 5, 0~800 p.p.m. 0 1 0 2 0 0 3 , Grade 4, 801——l600 p.p.m. l 6 4 l 0 0 l2 ; Grade 3, 1601-1-3200 p.p.m. 1 2 10 3 3 0 19 Grade 2, 3201-45400 p.p.m. l. 1 4 3 10 1 20 . Grade 2, 16401 p.p.m. or more 1 0 1 1 9 . 2 - 14 erage 6.98 6.26 6 18 6.41 6.33 7.44 Grade 5, below 5.0 0 0 0 2 1 0 3 Grade 4, 5.1—5.5 0 '2 3 O 5 0 1O Grade 3, 5.6—6.0 0 3 5 1 3 0 12 Grade 2, 6.1——7.5 3 4 11 6 13 2 39 Grade 1, 7.6 or more 1 1 0 1 0 1 4 .were more acid than pH 5.0. The pH was below 6.0 in 25 of the 68 __ samples; while soil acidity may not be a limiting factor for the growth of g grasses on most of these soils, it is possible that some of the soils are suf- ficiently acid to respond to the application of lime, particularly for the 4.} growth of legumes. ' Significant differences in average composition and in distribution in ,4 the different grades occurred among the soil groups. Hockley and Katy soils were considerably lower than any other group in several constitu- igents. Edna soils were higher than those of the Hockley-Katy group in nitrogen and active lime but the same in total phosphoric acid. Light-tex- “T*tured soils of the Lake Charles series were practically the same as the j Edna soils in all constituents, while the heavy-textured soils were the a highest of any of the upland groups. Considerable variation in the com- position of the Harris soils is evident. Alluvial soils were much higher in I a all constituents than any of the upland groups. RELATION OF CHEMICAL COMPOSITION OF SAMPLES OF FORAGE TO DIFFERENT GROUPS OF SOILS It is important to know whether there were important variations in the average chemical composition of forage as related to different groups of soils. In order to study this question, two groupings of the soils were made. The first grouping was based on the nature of the soils, as indicated by the name of their series, or in the case of the Lake Charles _ series, whether light-textured or havy-textured. The second grouping was based on the chemical composition of the soils. The average protein, 26 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION phosphoric acid, and lime in all samples of forage at different stages of growth were calculated for each soil group. For this purpose, the samples at the medium and bloom stages of growth (Table 2) were combined and designated as intermediate growth. The percentages of the total number of samples from each group of soils which contained protein, phosphoric acid, or lime percentages within different ranges were also ascertained. Because of the marked decrease in the percentage of protein and phos- phoric acid in the grasses at different stages of growth, the limits chosen were different for the different stages. Limits for lime were the same for all periods of growth, since the lime percentages were fairly constant. Effect of the General Nature of the Soil The data with respect to the general nature of the soils are given in Table 8. In the young samples of grass, protein was lowest in those from the_Hockley-Katy group (8.60%) and highest in those from the light-tex- tured soils of the Lake Charles series (9.54%). The difference between the Edna soils (9.02%) and the heavy-textured Lake Charles soils (8.94%) is probably not significant, but the other differences are significant. Protein in the samples of forage at the intermediate stage of growth was definitely higher in those grown on the Edna soils (5.99%) than in those from any of the other soils (about 5.5%), which did not vary significantly among themselves. Differences at the mature stage of growth were relatively small, with a slight advantage in favor of the light-textured Lake Charles soils. For all of the samples, protein was slightly but significantly lower in the samples from the Hockley-Katy. soils than in those from any of the other groups, among which the differences were quite small. Phosphoric acid was definitely lower in the samples from the Hockley- Katy and Edna groups than in those from either of the Lake Charles groups. At the young stage of growth, samples from the Hockley-Katy group averaged only .27 % phosphoric acid, with 75% of the samples being deficient (below .33%); those from the Edna soils averaged .31% phos- phoric acid, with 61% of the samples deficient; those from the Lake Charles soils averaged about .35% phosphoric acid with only about half of the samples deficient in phosphoric acid. At the intermediate stage of growth, the Hockley-Katy soils were again lowest (.19% phosphoric acid, 37% of the samples below .17%), but the differences among the other groups were very small. At the mature stage of growth, the differences among the soil groups were very small, but the proportion of samples which were very deficient in phosphoric acid (below .17 %) was much higher in the Hockley-Katy (88%) and the Edna (78%) soils than in the Lake Charles soils (55% and 66%). Overall averagesalso show that the samples from the Hockley-Katy soils (.22% phosphoric acid) were defi- nitely below those from the Edna soils (.25%), which were in turn below samples from the two groups of Lake Charles soils (.28% and .28%). Lime was definitely lower in the samples from the Hockley-Katy soils (overall average of .57 %) and the Edna soils (.56%) than in those from the groups of Lake Charles soils (.64% and .64%). Lime averaged slightly higher in the young samples. than in intermediate or mature samples, but the differences were probably not significant. As previously noted, very few of the samples were deficient in lime. 27 COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 3 mm on 5 Ne. 0H mm 3 mm S. w 3 3 Nu 8.» 8 KSMIBIEQ 0M3 b wm 2 2 3. S mm 5 m: 3. w om 3 a 3...“. w» finzqluwiwze 0E H mm mm m» E. m om fi m 3. w Z .2. u.“ 22 3 55H 3 mm mm “a m. o we § .5 MS. o mm 3 2 23 .2. ksdflhwfioaw Qflouw mew some Qfloam 5cm some 86.8 :3 zoom "COMM mBQEQm we owmuiwupwm EoCmoEEam we wmwufloopoh 59C mwasdm we omdaioononm $%. $~w $3 ~53. $§. $§. $2. $2. $§ $3 $3. $§ .$>C op mm. ea 2. 3 o uwvO o» 5. o» I. 3 o ne>O o» 3. 3 9m 3 o mania cm QEMQ wwnfiq c“ Eon oiecawosm mafia? E 538m sfigum we owwum 0.25.2: on» as owunoh wfl 3 3 3 E... S .3 5 3 mm. m“ N” w.» m wwm u»; >>8ml8iéoe ov-dQ m“ § Ev m 3. 3 mm m“. . 3 ma. um m” 5 w a3 3L Ewmqlwsbwpo wfifi 2 § 2. 8 mm. 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Hm m .5.» 2 .$8Ta_%.¢m 250mm mew some 56.5 Com some Qnonm mom no.8 59C mBQEMm we wmnecoopwnw Eon» mwafism we wwwpflwopwnm EOHM moEEnm we owwwimouvh $~w $3 $3 $3 $2.. $2. $%. $8. $3: $1: $wm $3 .$>O o» 3. 3 2. 8 o .$>O op mm. 2 S. 3 o. pw>O o» mi o» ed o» o main?“ E QCEA 3:29 E Eva oiesemesm mucfifl E flmouounm 532w we wmwam Munoz ma» an wmwpeh 3:5.- 35:: 3:5: E Eon uiozawosn E Eon 530.5 E moi-Eda 0E: o» $253 :33 0E: 3 3233 J33 uiosamosa o» goon-woe :23 E395 mo minim» we iomunnmuummi oueuo>< QU~QEQM we zoflnfiuummfi $393. moi-flan we Gofiuaiwmmfl $303.‘ uon-HBZ fiBeuH flow we 253w ofiouuwfiv 59C ~25 macoztuniou we £95- uaouowfiw uE-iauioo 5.35am @938 we moaaanuuhon win duflmioauahuso _c.-o=oM no woman mica iofiioafiou 131:3? ouduo>< a 03:8 2S BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION In addition to the four i-nain groups of soils just discussed, some forage samples were collected from a few locations on alluvial soils and Harris soils. Samples of grasses from three alluvial soils at the young stage of growth averaged 11.45% protein, .57 % phosphoric acid, and .6392 lime. The inclusion of Lespedeza striata in the averages changed them to 14.02% protein, 55% phosphoric acid, and .92% lime. The young forage from these soils was thus comparatively high in protein, phosphoric acid and lime. At the intermediate stage of growth, forage from one of the Miller soils averaged 6.24% protein, .38% phosphoric acid, and .80% lime; protein was no higher than in corresponding samples from upland soils but phosphoric acid was considerably higher. Forage samples from four Harris soils, which lie very near the Gulf and on which growth was com- paratively sparse, averaged 10.07% protein, .39% phosphoric acid, and 46% lime at the young stage of growth; at the intermediate stage of growth, the averages were 5.85%, .22%, and .47%, respectively. These av- erages are very similar to those for similar forage samples from the usual upland soils. Very few of the soils produce forage which is deficient in protein at the young stage of growth, or which is not deficient in protein at the ma- ture stage of growth. Most of the soils on which native grasses predomi- nate probably produce forage which is deficient in protein at intermediate stages of growth, while many of those on which certain of the better grasses, such as Bermuda, Dallis, and Johnson grasses predominate, may produce forage in which protein is not deficient. Many of the soils, par- ticularly of the Hockley, Katy, and Edna series, produce forage which is deficient in phosphoric acid at all stages of growth. Most of the common upland soils produce forage which is deficient in phosphoric acid at inter- mediate and mature stages of growth. Some of the alluvial soils produce forage which is not deficient in phosphoric acid at intermediate and ma- ture stages of growth. Effect of the Chemical Composition of the Soils Protein in samples of young forage from soils containing different levels of total nitrogen (Table 9) increased significantly as the total ni- trogen in the soils increased. At the intermediate and mature stages of growth, however, differences in average protein content of the forage were very small and showed no relation to the quantity of total nitrogen in the soil. The distribution of the samples containing the same levels of protein but grown on soils containing different levels of total nitrogen did not vary significantly with the different soil groups. These results are in substantial agreement with those of work previously published (17) which showed that, for nitrogen, the relation between the plant and the soil is much closer in young samples than in older ones. Phosphoric acid in the young forage increased significantly as the quantity of active phosphoric acid in the soil increased beyond 30 parts per million. However, three-fourths of the young samples collected were from soils in which active phosphoric acid was below 30 parts per million, and of these samples, two-thirds were deficient (below 33%) in phosphoric acid. At the intermediate and mature stages of growth, the average phos- phoric acid in the samples was low until the quantity of active phosphoric Z9 COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE w HQ mm 3 Hé. mm 03$ n0>O 00H 0 o o 3. H 00H .H0>O Hm mm om HNH 1.. mm Q30 8 2% mH Hm mm mH mH. 3 00H 0» Hm 0 oH wm m0 N3 m0 000E. n0>O m 5 m Hm 0m. >0 comm 8 H2: o 0m Hm mH 0H. 8 om 0w mH m m HH m» 3am mm owH. 8 HmH. o Hm mm. Hm Hem. mm 83 00 o w 0H E 0H mH. fi. wH 0H o q mH mm mm m3 3 omH. S. o 002w HHow 0000 500w 0500M HHom £000 . 550M HHem c000 wwHnHiww we 0000000000 500w wwHQfiww wo 003000.05 500w mwHnHHbmw we 000008.30 00.0mm. 030$. $00.. 00E. $3.002. 00$ $0.». $3 02$ .H0>O 8 mw. 0w m0. o» o 00>O 0w pH. 00. 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EO.H% EH UQHQIQ&QFQO *6 I~0>0~ HHHQMOMMmU ufifiawiou MQ-GEND QNQHOW HG UQMQwQNOHOQ 0:0 HnOmHmmOQH-HQO —GOmEOH.—Q 0MBHO>< »m Qmfiflhw 30 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION acid in the soils exceeded 100 p.p.m. Unfortunately, only 6 of the 68 soil samples contained more than 100 p.p.m. active phosphoric acid ,and from these soils, only 55 samples of the forage were collected. The low number of samples from these soils decreases the significance of the averages. In order to secure a differentiation in the bulk of the samples, which were from soils containing active phosphoric acid in Grade 5, or less than 30 p.p.m., the grade was divided into two sections of 0 to 18 and 19 to 30 p.p.m. However, as shown by both the average phosphoric acid in the samples and the distribution of the samples at different levels of phosphoric acid content, there was no significant difference between these two groups of soils. Lime in the forage at all stages of growth increased significantly with increases in the level of active lime in the soils. This is shown both by the average percentage of lime in the samples and by the distribution of the samples as related to the lime content of the soils. As the quantity of active lime in the soils increased, a larger proportion of the samples con- tained higher percentages of lime. None of the soils was sufficiently low in active lime to produce forage which was deficient in lime (below .22%). The effect of variations in both nitrogen and active phosphoric acid in the soil upon the protein and phosphoric acid in the forage is shown by the averages given in Table 10. Protein in the forage increased sig- nificantly with an increase in the level of either nitrogen or active phos- phoric acid in the soil. Averages for protein ranged from 7.34% in forage from soils containing less than .120% nitrogen and 17 parts per million Table 10» Effect of different levels of nitrogen and active phosphoric acid in the soil upon the percentages of protein and phosphoric acid in young forage Total nitrogen in soils 0 to .120% .121 to .180% .18l% or more Active phosphoric acid in soils Protein in forage 0 to 16 p.p.m. 7.34 8.93 9.73 l7 to 30 p.p.m. 8.15 9.14 10.88 31 to 100 p.p.m. 9.87 9.59 11.37 101 p.p.m. or more 11.11 11.79 12.75 Phosphoric acid in forage 0 to 16 p.p.m. .26 - .31 .32 17 to 30 p.p.m. .26 .32 .32 31 to 100 p.p.m. .36 .43 .48 101 p.p.m. or more .65 .56 .53 active phosphoric acid to 12.75% in forage from soils containing more than .180% nitrogen and 100 p.p.m. active phosphoric acid. At the same level of one constituent in the soil, protein in the forage increased significantly with an increase in the other constituent in the soil. At the lowest level of nitrogen in the soil, the range in protein associated with increased active phosphoric acid in the soil was from 7.34% to 11.11%; at the lowest level of active phosphoric acid, the range associated with increasing levels of nitrogen in the soil was from 7.34% to 9.73%. The increase in average protein was due to an increase in protein among the samples of the same species and also to the fact that species normally higher in protein were found more frequently on the more fertile soils. COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 3] Phosphoric acid content of forage from the different soil groups did not change as markedly nor as regularly as the protein. The range in phosphoric acid was from .26% in forage from the lowest soil group to 53% in forage from the highest soil group. The relation is apparently reversed in soils containing more than 100 p.p.m. active phosphoric acid, but the number of samples in these groups was small. Changes in the averages in forage from soils containing less than 30 p.p.m. active phos- phoric acid were quite small. In these groups, it seems probable that an increase in the quantity of either active phosphoric acid or nitrogen in the soil was accompanied by an increase in the quantity of forage produced on the soil, so that while more phosphoric acid might have been removed from the soils by the plants, it Was distributed through more plant material and had little effect or no effect upon the percentage of phosphoric acid found in the forage. However, considering all groups, there seems to be a defi- nite increase in phosphoric acid in the forage with an increase in either nitrogen or active phosphoric acid in the soil. EFFECT OF SOME PASTURE PRACTICES UPON THE CHEMICAL COMPOSITION OF FORAGE The work just presented has shown that different species of grass vary markedly in average chemical composition, that percentages of pro- tein and phosphoric acid in the forage decrease significantly as the plants pass from the young to the mature stages of growth, and that there is a definite relation between the chemical composition of the forage and that of the soil on which it is grown. These facts suggest the possibility that certain pasture practices may increase considerably the quality of forage available to grazing animals. Mowing tends to keep the forage at a younger stage of growth, with relatively high percentages of protein and phosphoric acid, and may promote the growth of more desirable species of forage plants. Rotational grazing, properly conducted, would have essen- tially the same effect as mowing. Fertilization of the soil, particularly with fertilizers carrying phosphoric acid, may increase the percentage of protein and phosphoric acid in the forage and often results in an increase in the proportion of forage supplied by more desirable species of plants. During the course of the work reported in this bulletin, information on these subjects was secured from a number of experiments. The results of these experiments will be discussed in the following sections. Effect of Mowing the Pastures An experiment to determine the effect of monthly mowing on the yield and chemical composition of pasture grasses yvas conducted by the Division of Agronomy on plats at Substation No. 3 at ‘Angleton during 1934 and 1935. The plats supported stands of different species or combi- nations of species of grasses. The pure stands of grasses included Angle- ton, Bermuda, carpet, and Dallis grasses; mixed stands of native pasture grasses (principally little bluestem, big bluestem, and bushy beard grasses) and of improved pasture grasses (Bermuda, carpet, and Dallis grasses) were included in the experiment. Agronomic aspects of the re- sults have been discussed and detailed chemical analyses of the samples have already been published (29), but the general results secured are pertinent to the work discussed in this bulletin. ‘ All grasses Unclipped 5.13 l 32 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION Table 11. Effect of clipping monthly on average chemical composition of forage ‘ (percentages of air-dry matter) Grass Treatment Protein Ether Crude Nitrogen- Water Ash Phospho extract fiber ree ic acid extract .. Angleton Clipped 7.80 2.45 24.93 42.93 8.23 13.64 .29 f Angleton Unclipped 3.58 1.97 34.72 42.79 8.29 8.66 .14 i Bermuda Clipped 9.78 1.91 21.87 44.73 7.82 13.88 .31 Bermuda Unclipped 5.81 1.55 23.46 49.36 7.80 12.02 .19 ‘_ Carpet Clipped ~ 9.3-6 1.70 23.09 45.66 8.43 11.76 .27 » Carpet Unclipped 5.63 1.25 26.24 46.85 8.37 11.66 .18 . Dallis Clipped 10.23 2.40 24.53 40.18 7.74 14.91 .32 - ‘ Dallis Unclipped 5.86 1.74 30 03 43.79 8.12 10.44 .19 ' l Improved Clipped 9.08 2.03 25.06 43.73 7.88 12.21 .29 \ g Improved Unclipped 5.49 1.78 29.88 45.97 7.90 8.98 .18 f l Native Clipped 9.33 1.99 26.15 42.11 7.94 12.51 .29 Native Unclipped 4.33 2.00 29.99 46.99 8.15 8.54 .17 i All grasses Clipped 9.26 2.08 24.27 43.24 8.01 13.14 .29 1.71 29.05 49.95 8.10 10.06 .18 The soil of most plats was a Lake Charles clay loam, with some small . areas of Lake Charles fine sandy loam. Soil samples from all of the '5 plats were analyzed for some of the more important constituents. The j soils of the various plats did not differ significantly among themselves chemical composition. Averages of the constituents in the surface soils (0= g to 6") were as follows: Nitrogen, .l43%; active phosphoric acid, 16 p.p.m.; ‘i active lime, 3695,p.p.m.; active potash, 139 p.p.m.; basicity, .84%; pH, 6.6. Q § The soils were thus well supplied with nitrogen and active lime, compara- '~ tively low in active potash, slightly acid, and very low in active phosphoric j‘ acid. i. Averages of the principal constituents of the clipped and unclipped ‘ forage samples are shown in Table 11. Protein and phosphoric acid in samples from plats which were clipped monthly averaged nearly twice as '5; high as in the samples from plats which were not clipped. The overall average for protein was 9.26% in the forage from clipped plats and 5.13% in that from the unclipped plats. Protein was deficient (below 6%) in none of the 92 samples from the clipped plats and in 49 of the samples .-¥ from the unclipped plats. Phosphoric acid was deficient (below .33%) in’ 54 of the samples from the clipped plats, of which none were very defi-c- cient (below .17%). Phosphoric acid was deficient in 77 of the samples T} from the unclipped plats, of which 46 were very deficient. Lime was slightly higher in the samples from the clipped plats except in the case of the mixed native grasses; the overall averages were .62% and .54%. Crude fiber was significantly lower in the samples from the clipped plats (24.27%) than in those from the unclipped plats (29.05%). N itrogen-free ex- Q tract was slightly lower in samples from the clipped plats (43.24%) than in those from the unclipped plats (49.95%), except in the case of Angleton grass. Monthly clipping thus greatly increased the protein and phosphoric g acid, slightly decreased nitrogen-free extract, and markedly decreased v crude fiber in the forage. A The evidence concerning the beneficial effects of clipping secured in this plat experiment was corroborated by analyses of forage collected un- der normal range conditions. Samples of little bluestem grass fromi mowed and closely adjacent unmowed areas were secured in the fall from several locations in ordinary pastures. Protein in the samples collected on as COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 33 Table 12. Average chemical composition of forage collected in April, July, and in October following summer mowing (percentages of air-dry matter) Month when Katy fine Lake Charles Miller collected sandy loam fine sandy sandy loam loam Protein April 8.46 9.07 11.23 July 4.50 - 6.27 6.58 October 6.13 7.27 8.10 Phosphoric acid _Apri] _.30 .44 .61 July .14 .23 , .33 October .20 .27 .41 Lime — April .80 .45 .62 July .57 55 .99 October .57 .68 .72 the same date from the mowed areas and from the unmowed areas aver- aged 9.52% and 5.56%, respectively; phosphoric acid averaged .40% and 20%; lime averaged .56% and .61%. Protein and phosphoric acid were thus nearly twice as high in the samples from the mowed areas as in the samples from the unmowed areas; lime was slightly higher in the samples from the unmowed areas. Another comparison was made of the influence of mowing upon the marked reduction in protein and phosphoric acid usually occurring in late fall samples, as compared with samples collected earlier in the year. Typi- cal of results secured are the data presented in Table 12 for the average chemical composition of all forage samples collected from three sandy loam soils. The principal difference in the chemical composition of these ’ soils was in the active phosphoric acid, of which the Katy fine sandy loam contained 20 p.p.m., the Lake Charles fine sandy loam, 70 p.p.m., and the Miller sandy loam, 195 p.p.m. These differences in the active phos- phoric acid content of the soil were reflected in the averages of phos- phoric acid found in the April samples of forage, which were .30%, .44%, and .61%, respectively. Samples of forage were secured from these soils in April, July, and October of 1940; subsequent to the sampling in July, these areas were all mowed by the owners. The effect of the mowing upon the chemical composition of later forage is shown by a comparison of the July and October samples. Protein and phosphoric acid in the October samples were considerably higher than in the July samples. The effect with respect to lime is not regular nor important, since all of the samples contained sufficient lime. Early fall mowing thus resulted in late fall forage which was higher than summer forage in protein and phosphoric acid. All of this evidence indicates that mowing has a beneficial effect upon the protein and phosphoric acid content of the forage. ' Effect of Fertilization of the Soils An experiment to determine the effect of various fertilizers upon the yield of forage grown on plats at Substation No. 4 at Beaumont was started by the Division of Agronomy in 1935. During 1938 and 1939, the samples collected for yield data were analyzed by the Division of Chem- 34 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION Hm; mNA oNA Fm; E2 EA ma; 1E 2E NNA Bfigmofiiwmsm E8 wni: n wfisfiogfifiww NTN Nw; ma; 2N £4 3A m: £4 £4 5.4 Bfimwosgiwgi E3 0E: u 25A $4 3A 2A EN Nmé 3A Q3 3i f; $4 Bwsnmopfiwnsm n 2:5 £4 :3 Nm; >N.v .3; $4 2.» £4 £4 2a Qfisnwozfiwism E8 oiifl wimN £4 NNA i.” $4 $4 wwN om; mNA >o.N mic?“ Qafiqwanfiwifiw 3i NH; NH; :4 22 m3 £4 23 mo; 34A miofim wiifl "wawiimoniimiim i0 0E2 QZ woé Q2 8i 3. 2w. ma. EA w». :2 24 Amdpoi u ifioa oZ 23 5. 2w. 23 9.3 23 $4 3A w». 23 wfiwfiim iiiioiiiiw n c382: QZ 2i mm. mm. :4 8i 23 2A 2w. 3 :4 ouwifii Efiwom n imwoifii OZ , u H HH woimwim. ow wwawwfiiD lwomawfl Maw NmA wNA N13“ fi. 3w i; $3 wi: £3 wfiaimogfiwfidw vim oiJQ W5 S: £3 mMN g 3% mam. 53 2.2 3E mic? wfiifiwoggiwgfi ma” ma. mm. 9: mN. ma. Q3. 23. m?” £5 mic? oiifl wdN E. mm. mi mN. wN. SN 2E Nfiw 22.. wafinmeimiwium no 0E3 oZ ed» £4 2A cdN 3i Q. 5% HNdH 2.3 mm? £38m v.3 3A NH; m2 ma» 2. 2a 3.3 NW2 6:. 55cm o2 mzwN 2W. 2. Nd mN. NN. wmN 2w 3w 3km fisssm Esmcoiaz» m.wN Nw. aw. m6 mN. NN. 8N Riv Niiw m3” mafia? 6.56m mSN Na. 8. M2 mN EN. 3N 2w Ea m»? ivmoifii OZ \ mwaiow i“ wiiorm <\..= @0222» ~§$u< <\..= qwiww? i25u< 4%.: wvium»? 12:34 <\..: dwfifi mouneiouiun éwmiou mounaiuouun Jwwicw mounuiwuioa $wsicw i“ owaio>< i“ omniw>< E ouauo>¢ mo 13.5. 1:5. 139-. Bu?» 351m Bow omicsamosh imam-cum 13cm. ¢umi8 im Vin-OM nuioifiamicu 73o“- wis icmfimoniiou .30?» us» ion: iofiwuflmviom no wovwwfl .2 03am. COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 35 istry for protein, phosphoric acid, and lime. The results 0f this work have already been reported in detail (16). However, they are pertinent to the work reported here and a summary of the results secured in 1938 is shown in Table 13. The soil used was a Crowley clay loam, a heavy-textured soil which closely resembles the Lake Charles soils. It was fair in nitrogen (126%), weakly acid (pH of 5.8 on untreated plats), and very low in active phos- "phoric acid (23 p.p.m.). The total yields shown in Table 13 are the sums of weights of the crops removed by mowing with a lawn mower in March, May, June, July, August, and September of 1938. The actual averages for the constituents are the averages of the analyses of the six crops; the weighted averages were calculated by multiplying the weight of each crop by the analysis of that crop and adding the products, thus securing the total weight of the constituents in the forage, and dividing this sum by the total yield. Where the weighted averages are significantly higher or lower than the actual averages, a larger proportion of the total yield contained percent- ages of the constituent which were relatively high or low. Sodium nitrate increased the yield of forage by 17%, but did not sig- nificantly change the chemical composition of the forage. Ammonium sul- fate and muriate of potash had no significant effect upon either yieldlor chemical composition. Lime on the plats which did not receive phosphates increased the yield of forage by 45% and the percentage of lime in the forage by 18%, but had no significant effect upon percentages of protein or phosphoric acid. The difference between the actual and weighted averages for protein is due to small early spring samples which contained some lespedeza, which was quite high in protein. Lime on the plats which received phosphates in- creased the yield of forage and percentage of lime by 22%, but had no effect upon percentages of protein and phosphoric acid. Superphosphate on the unlimed plats more than doubled the yield of forage, increased the percentages of protein and lime by about one-third, and increased the percentage of phosphoric acid in the forage by more than one-half. Superphosphate on both unlimed and limed sections greatly reduced the number of samples of forage which contained less than 33% phosphoric acid and were therefore probably deficient in phosphoric acid for range animals. Of the samples averaged in the data given in Table 13, l7 of the 18 samples from plats which had not received superphosphate or lime and 15 of the 18 samples from plats which had received lime but no superphosphate were deficient in phosphoric acid (weighted averages of .2970). None of the samples from plats which had received superphosphate were deficient in phosphoric acid (weighted averages of .44% 0n unlimed plats and .48% on limed plats). Results for 1939 were essentially the same as those for 1938, except that low rainfall reduced the yields of forage. Samples of forage from both phosphated and unphosphated plats collected in January and Decem- ber, 1938, when the forage was fully matured, were deficient (below .33%) in phosphoric acid. 36 BULLETIN NO. 644, TEXAS AGRICULTURAL EXPERIMENT STATION Favorable results similar to those secured on the plat experiments were secured in one comparison in ordinary pastures. On the area con- cerned, one part of a pasture had received 200 pounds of 18% superphos- phate in August, 1936, while a companion area had received none. In April of the next year, samples of carpet grass and of tickle grass were secured from both areas; the distance between the areas sampled was only a few feet across a fence. Carpet grass from the fertilized area and from the unfertilized plats contained, respectively, 8.48% and 8.26% protein, .38% and .31% phosphoric acid, and .63% and .54% lime. Tickle grass from the fertilized and unfertilized areas, respectively, contained 10.30% and 8.57% protein, .71% and .53% phosphoric acid, and .36% and .32% lime. The data in both cases indicate significant increases in lime in for-' age following the use of fertilizer, but the comparative increases in protein and phosphoric acid were different for the two species, being small for carpet grass and large for tickle grass. Fertilization of pastures with superphosphate will, in many cases, in- crease the total production of forage, increase the percentages of phosphoric acid and protein, and promote the growth of legumes and more nutritious grasses. ACKNOWLEDGMENT Credit is due Mr. T. L. Ogier, Mr. S. E. Asbury, Mr. Waldo Walker, and other members of the staff for analyses and other worknecessary in securing the data here presented. SUMMARY Protein, phosphoric acid, and lime were determined in 1,140 samples of various species of forage at four stages of growth collected at various times during the years of 1936, 1937, 1938, and 1940, from nearly a hun- dred locations distributed throughout the Gulf Coast Prairie of Texas. Crude fiber, ether extract, and nitrogen-free extract were determined in a considerable number of these samples. Protein, phosphoric acid, and lime varied widely with different species and with the same species at different stages of growth from different locations. Protein was highest in the few samples of legumes collected. The average protein content of the most important species of grasses at theyoung stage of growth ranged from 11.53% in Johnson grass to 7.19% in carpet grass; Johnson, Dallis, Bermuda, and Eastern gama grasses av- eraged more than 10.5% protein, while little bluestem and carpet grasses contained less than 8%. At the mature stage of growth, protein averages ranged from 6.16% in buffalo grass to 3.37% in little bluestem; buffalo grass was the only species in which the protein in mature samples aver- aged more than 6%, while protein in six important species averaged less than 4%. Phosphoric acid in samples of young grasses ranged from .59% in Johnson grass to .25% in carpet grass. In Johnson, Eastern gama, Dallis, bushy beard, Bermuda, and long-tom grasses, phosphoric acid averaged .40% or more, while in Georgia, little bluestem, and carpet grasses, it averaged less than .30%. Phosphoric acid in mature samples ranged from .38% in Dallis grass to .12% in little bluestem. In the mature samples, COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 37 Dallis grass was the only species in which phosphoric acid averaged above .25%; phosphoric acid in Georgia, big bluestem, and little bluestem grasses averaged less than .15%. Lime» in the samples of young grass ranged from 1.14% in Johnson grass to .50% in smut grass; in the mature grass, the range was from .78% in Dallis grass to .39% in bushy beard grass. Nitrogen-free extract usually ranged between 40% and 45% in young grasses and between 45% and 50% in mature grasses; differences among species at the same stage of growth were usually small. Crude fiber was usually lower in the young samples and increased with the age of the plants. Crude fiber was significantly lower in the short grasses, such as Bermuda and buffalo grasses (averaging about 25%), than in the tall bunch grasses (averaging about 30%). In order to facilitate comparison between the samples and to provide an approximate estimate of their relative quality, the samples were grouped into grades according to their percentages of protein, phosphoric acid, and lime, as was done in previous work. ' The distribution of the samples in the different grades varied widely with different species, stages of growth, and the constituent concerned. The proportion of samples which were deficient in protein and phosphoric acid was much larger in tall grasses than in short grasses, and in mature g grasses than in young grasses. Protein was deficient in 55% of the samples of little bluestem and only 13% of the samples of Bermuda grass, in 12% of all young samples, and in 92% of all mature samples. Protein was good or high in 122 of the total of 1,140 samples; 110 of these were samples of young forage. Phosphoric acid was deficient in 65% of the samples of little bluestem and 39% of the samples of Bermuda grass, in 59% of all young samples and in 96% of all mature samples. Phosphoric acid was high in no sample and good in only 15 of the 1,140 samples; of these, 12 were young forage. Lime was deficient in only 5 samples, and good or high in 82% of 1,140 samples. The average chemical composition of 6 groups of soils, comprising a total of 68 individual soils from which forage samples were collected, and the distribution of the soils with respect to grades of their constituents, are shown. Of the 68 soils, the numbers of soils which were deficient in total nitrogen was 1, in total phosphoric acid, 58, in active phosphoric acid, 64, and possibly in active lime, 15. Protein in forage samples was slightly but significantly lower in samples from the Hockley-Katy group of soils than in those from any of the other soil groups. Phosphoric acid and lime were lower in samples from the soils of the Hockley, Katy, and Edna series than from any other soil groups. The percentages of protein and phosphoric acid in young samples of forage, on an average, increased with an increase in either total nitrogen or active phosphoric acid in the soil. At intermediate and mature stages of growth, differences in protein and phosphoric acid in the forage from dif- ferent groups of soils were very small. Lime in the forage at all stages of growth increased significantly with increases in the level of active lime in the soils. .':i' ..~ . 38 BULLETIN NO. 644. TEXAS AGRICULTURAL EXPERIMENT STATION E Mowing of the pastures greatly increased the percentages of protein", ' and phosphoric acid in the forage, slightly decreased the nitrogen-free ex~gé tract, markedly decreased the crude fiber, and slightly increased the lime}; In an experiment on the value of different fertilizers for forage on plats of a Crowley clay loam, nitrogen and potash had little or no effect =~ upon the yield or chemical composition of the forage. Lime increased the‘ ‘ yield of forage by 45% and the percentage of lime by 18%. Superphos-j‘ phate increased the yield by 107%, and caused relative increases of 30% ' in the percentage of protein in the forage, 52% in phosphoric acid, and 35% in lime. Lime and superphosphate together caused relative increases of 153% in yield, 35% in percentage of protein, 65% in phosphoric acid,’.€ and 67% in lime in the forage. The forage grasses of this area do not contain enough phosphoric acidg i. to give the best results with range cattle. The young grasses are better’, supplied with phosphoric acid than the older grasses. The mature grasses; are also low in protein. Very few of the grasses were deficient in lime. The deficiency of phosphoric acid can be supplied by feeding minerals; containing phosphorus or by fertilizing the soils with phosphates. Fertili-iji zation has, in most cases, improved not only the quantity and phosphorus content of the forage, but has also encouraged the growth of legumes and of grasses which supplied a more favorable quality of both phosphorus and protein. 1 l.- t ‘IWJQ-K-M’ -< @141,‘ .,;,,,4w._-‘,.,; r ‘ , y . . LITERATURE CITED 1. Archibald, J. G., and Bennett, E. 1935. The phosphorus requirements of dairy heifers. Jour. Agr. Res. 51: 83-96. -, 2 Armsby, T. P. 1917. The nutrition of farm animals. MacMillan Co., New York. p’ 3. Association of Official Agricultural Chemists. 1940. Official and tentative methods of analysis. Washington, D. C. 4. Becker, R. B., Neal, W. M., and Shealy, A. L. 1933. Stiffs or sweeny (phosphorus de- ficiency) in cattle. Fla. Agr. Expt. Sta. Bul. 264. t,» 5. Beeson, W. M., Bolin, D. W., Hickman, C. W., and Johnson, R. F. 1941. The phos-K phorus requirement for growing beef steers. Idaho Agr. Expt. Sta. Bul. 240. ‘I 6. Bekker, J. G. 1932. 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The composition and utilization of Texas feeding stuffs. Tex. Agr.‘ Expt. Sta. Bul. 461. . ‘ 13. Fraps, G. S., and Fudge, J. F. 1937. Chemical composition of soils of Texas. Tex. ~-t Agr. Expt. Sta. Bul. 549. 14. Fraps, G. S., and Fudge, J. F. 1937. Phosphoric acid, lime, and protein in forage grasses of the East Texas Timber Country. Proc; Amer. Soc. Soil Sci. 2z347-35l. g 15. Fraps, G. S., and Fudge, J. F. 1940. The chemical composition of forage grasses of the East Texas Timber Country. Tex. Agr. Expt. Sta. Bul. 582. 16. Fraps, G. S., Fudge, J. F., and Reynolds, E. B. 1943. The effect of fertilization of as Crowley c1ay_ loam on the chemical composition of forage and carpet grass, Axonopur affinix. Jour. Amer. Soc. Agron. 85:560-566. 1 28. 29. 30. 33. 34. 35. 36 COMPOSITION OF FORAGE GRASSES FROM GULF COAST PRAIRIE 39 Fudge, J. F., and Fraps, G. S. 1938. 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