Bulletin 846 January I957 Requirements fer GRAIN SURGHUM IRRIGATION en the Hie/z Plains in cooperation with the UNITED STATES DEPARTMENT OF AGRICULTURE TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS. DIRECTOR. COLLEGE STATION, TEXAS Summary and Recommendations Irrigation research was conducted with grain sorghum on the optimum use of undergroun resources at the Amarillo and Lubbock Experiment Stations and on off-station plots during r several years. t Highest returns in pounds of grain per inch 0f water are received when ligrain sorghum p plied with adequate moisture from planting to the soft dough stage. High-moisture levels are the most profitable; if the irrigation water supply becomes inadv the acreage to which water is applied should be reduced. A grain sorghum crop can be produced with a preplanting irrigation alone in very dry ye A‘ dryland crops are complete failures. ' w. Nitrogen fertilizers can be used to advantage with proper water management and will yields of 5,000 pounds or more of grain per acre. Definition of Terms Transpiration. The Water absorbed by a crop and evaporated from the plant surfaces. not include soil evaporation. It is expressed as acre-feet or acre-inches per acre, or as d, feet or inches. " Consumptive Use (evapo-transpiration). The sum of the volumes of water used by the v: growth of a given area in transpiration and building of plant tissue and, that evaporated from : 5 soil, snow or intercepted precipitation on the area in any specified time, divided by the givd If the unit of time is small, the consumptive use is expressed in acre-inches per acre or depth inf but, if the unit of time is large, such as a crop-growing season or a IZ-monthperiod, the cons I use is expressed as acre-feet per acre or depth in feet or inches. ‘ Water Requirement. The quantity of water, regardless of its source, required by a cri given period of time, for its normal growth under field conditions. It includes surface eva, and other economically unavoidable wastes. It usually is expressed in depth (volume per uni, for a given time. Irrigation Requirement. The quantity of Water, exclusive of precipitation, that is required production. It includes surface evaporation and other economically unavoidable wastes. It us T expressed as depth in inches or feet for a given time. t Irrigation Efficiency. The percentage of irrigation water delivered to the farm or field; available in the soil for consumptive use by the crops. When measured at the field or pl called field-irrigation efficiency. Water Utilization Efficiency. The crop yield produced per inch of water used consumptivj is expressed as tons of forage or pounds of grain per inch of water. ' Moisture Percentage. The percentage of moisture in the soil, based on the weight of the ~i material. Field Capacity. The moisture percentage, on a dry-weight basis, of a soil after rapid drai taken place following an application of water, provided there is no free water within capilla of the root zone. This moisture percentage usually is reached within 2 to 4 days after an o, irrigation, the time interval depending on the soil type. i Permanent Wilting Percentage. The percentage of water in the soil when plants wilt pe u a Available Soil Moisture. The amount of soil moisture available for‘ plant growth at any the difference between the moisture content of the soil and the permanent Wilting point. It... is expressed in inches of water per foot of soil depth or in inches of water for the root zone. The ence between field capacity and the permanent Wilting point moisture content of a soil is its available moisture storage capacity. 0' trquiréments for RGHUMS HAVE ALWAYS BEEN an important crop on the High Plains of Texas. The crop was a ‘gated soon after the first irrigation Wells were veloped in the 1911-14 period. There were ap- oximately 140 irrigation wells on the South ains (Southern High Plains) in 1914. The first ter-use studies with sorghum grain were con- cted near Plainview in Hale county in 1918-19 .- William L. Rockwell, a U. S. Department of 1 iculture irrigation engineer, in cooperation 'th the Texas Land and Development Company Plainview. j Dry weather in 1934-35 and the availability i more efficient pumps and power units stimu- ted further interest in irrigation. The number Wells on the South Plains increased from 300 § 1934 to 1,500 in 1938. The increase in the mber of irrigation wells continued and despite rtime restrictions there were 4,300 irrigation ells in the area by 1945. p Irrigation has doubled -or tripled grain sor- um yields obtained under dryland conditions on e High Plains of Texas and is a dominant fac- _r in the production of the crop. Over 4,300,000 ‘res of land are being irrigated from more than ,500 wells in the High Plains counties. More an 1,500,000 acres of grain sorghum were re- rted under irrigation in this area in 1955. The mber of wells, acres irrigated and acreage of ,_ gated grain sorghum reported in 1955 by the exas Agricultural Extension Service are shown "x counties in Figure 1. I Irrigation water on the High Plains is supplied ost entirely from underground water. This ,1.’ derground water resource is being depleted fur- er each season. At present there is no econom- lly feasible method of providing an adequate nual recharge of ground water. Use of this ater must be planned over a long period of years ther than 1 or 2 years as would be the case "th gravity irrigation from a reservoir and j reams with a known immediate supply. Irri- tion research with grain sorghum on the opti- um use of underground water resources has en conducted at the Amarillo and Lubbock sta- 'ons and on off-station plots during the past veral years. espectively, irrigation engineer, Soil and Water Con- ervation Research Branch, Agricultural Research Serv- ‘ce, U. S. Department of Agriculture, Lincoln, Nebraska, ormerly at Amarillo, Texas; and irrigation engineer, ubstation No. 8, Lubbock, Texas. GRAIN sonsnum IRRIGATION nni/lcfliy/l Plains NORRIS P. SWANSON and E. L. THAXTON, JR.* Research on the High Plains shows that good seedbed preparation and moisture conditions are required so that early germination, a good stand and a vigorously growing crop are obtained to shade and outgrow weeds. Weeds of the broad- leaved type can be controlled effectively by spray- ing with 2,4-D. Planting in close drill rows with- out cultivation is not recommended for fields known to be infested with grassy annuals. Climate Temperatures may fall below zero on the Northern High Plains during the winter and reach 106° on the Southern High Plains during the summer. The frost-free season averages 175 to 215 days from north to south. Sorghum breeders have adapted varieties to the length of season in their areas. Wind velocities often are high and the major wind movement normally occurs during the first 6 months of the year. The prevailing wind is from the southwest, and strong winds sometimes interfere with irrigation activities early in the Contents Summary and Recommendations _________ -- 2 Definition of Terms 2 Introduction -- 3 Climate 3 Soils 4 Experiments at Lubbock ________________________ __ 5 Experiments at Amarillo ________________________ __ 6 Experiments at Tulia ___________________________ __ 8 Water Requirements ___________________________ __10 Water Management 10 Consumptive Use _____________________________ __10 Preplanting Irrigations ____________________ __11 Frequency of Irrigation ___________________ __11 Depth of Application ______________________ __13 Efficiency of Water Use _______________ __13 Methods of Irrigation _______________________ __13 Acknowledgment 14 Literature Cited 14 OKLAHOMA DALLAM ‘sncaw-xu HANSFORD\OCHILTREE LIPSCOMB ' 105 105 210 52 15 20,000 55,000 05,000 15,000. 2,000 < Q 15,000 25,000 25,000 5550i _000 2 2 l-uxnnzv MOORE HUTCH. ROBERTS HEMPHILL x 54 15o 00 1 4 " 10 O L“ _4,2o0 _ 45,000 10,000. 550 700 I 2,410_ 25,000 12,000 1_?5 1_s0 < E OLDl-IAM POTTER CARSON GRAY ‘WHEELER A 45 20. 80 1 18 . 33 x 0,000 12,000 15,000 1,500 1,500 Lu 4,500 5,400 12,000 "r55 546__ Q Z DEAF 5mm RANDALL ARMSTRONG oowuav coL‘sw"r11 _ H909 _ 550 85 1 35 ' 500,000 05,000 25,500 5,500 \ 125,000 50,000 25,000 1.300 PARMER CASTRO SWISHER BRISCQE 1000 2500 5,000 555 5001000 5001000 -400,o00' 40,000 100,000 |125,400 |100,00o 20,000 BAlLEqLAMB HALE Tamra-T 1,050 2,000 5,700 2,000 145,00o'200,000 ,410,0o0-200,0o0 1,000 04,000 |250,150 125,000 -__i. cocuhAn lnocxuev LUBBOGK CROSBY 500 3,550 3,300 I 360 40,000 '255,000 -525,0o0 '15o’,000 0,000 55,000 125,000 50,000 YOAKUM TERRY 1mm GARZA I65 _ 700 1,500 240 26,000 70,000 148,000) 112,000 14,000 0,000 1 0g 5 GAINES DAWSON BORDEN 550 550 1 s 550,000 40,000 000 27,5 50 1, _000 _0 ANDREWS mmrm HOWARD , 250 ' 10 22,000 70o I 700 o Figure 1. Number of wells (top figure), acres irrigated (middle figure) and acres oi grain sorghum irrigated (bottom figure) on the High Plains of Texas as reported by the Extension Service in May 1955. season. In some years sorghum fields may suffer damage from Wind before harvest. Hail damage occurs in some locality almost every year but widespread damage to sorghum is uncommon. The variability of rainfall and extended per- iods of drouth are the greatest problems encoun- tered in producing grain sorghum on the High Plains. Average annual precipitation varies from about 21 inches along the eastern edge of the» High Plains to 15 to 18 inches along the Texas-New Mexico state line. Most of the rainfall is received during the April-to-October growing season. The winters usually are dry with little snow, which provides little soil moisture. Evaporation is high and averages from 80 inches annually in the south to 75 inches annually in the north. Erratic rainfall and poor seasonal distribution of moisture frequently result in poor crop yields during years of above average rainfall. The av- erage monthly distribution of rainfall at Amarillo, Table 1, and at Lubbock, Table 2, shows that few 4 “average” years are anticipated. About 3’ out of 5 have below average monthly rainf _ other 2 years of average-to-high monthly i provide and maintain the average. The received during a season may vary widel one locality to another. During the ' months of 1948, Amarillo received more inches of precipitation, whilje Lubbock, 12 i south, received less than 9 inches. ,- An analysis by J ensenl shows that 34 of the precipitation received at Amarillo‘ the 30-year period, 1920-49, was in am 0.50 inch and less, while less than 40 pe the precipitation was received in amounts ‘ ing 1.0 inch. One rain in excess of 1.0 i , three rains ranging from 0.50 to 1.0 inch can be expected during July and August. g Soils The soils of the High Plains are clash? three general groups: the hard or tigh - the mixed or catclaw lands and the sand The hard lands comprise about 70 percen; cultivated land and the mixed land about-g cent. A generalized soils map of the Hig" is shown in Figure 2. ' The hard or tight lands, generally clas, Pullman silty clay loams, consist of 6 to 1___ of clays or clay loams over heavy clay , with soft caliche layers. at a depth of 3;, more. These soils absorb Water slowly bu high water-holding capacity. They usu capable of storing over 2 inches of avail ter per foot of soil depth. Intake rates i low as 0.10 inch per hour or less, but Wit management practices, intakes of 0.25 inch per hour can be obtained. b The mixed lands generally are Ami Portales fine sandy loams. These soils- water more rapidly and have a mediu ‘ holding capacity of 1.5 to 2 inches of moisture per foot of depth, with intake, 1 to 2 inches per hour under normal c0, TABLE l. A 63-YEAR SUMMARY OF NORMAL TION BY MONTHS, AMARILLO STA 1954 Average Years Tears Month rainfall. . below wnhm l/i 3 inches average. of average. ._ percent percent Ianuary .64 67 22 February .62 63 21 March 1.04 73 l3 April 1.45 56 14 May 3.01 60 22 Iune 3.25 71 21 ’~ luly 2.36 60 25 August 2.99 54 25 i’. September 2.28 ' 63 24 October 1.93 _ ' 65 l4 November .88 62 l3 December .67 56 17 Yearly average 21.13 l hey consist of 6 to 12 inches of clay loams over ine sandy clay subsoils with a caliche layer at e» depth of 3 feet or more. _ The sandy soils have lower water storage ca- - acities and have not contributed greatly to the ‘acreage of irrigated sorghum. Shallow soils often are found on the steeper lopes around playa lakes. These soils because of heir lack of depth and low moisture storage ca- acity are not well suited for grain sorghum pro- uctions. Experiments at Lubbock An irrigation well was completed at the Lub- bock station late in the spring of 1936 and irriga- ion experiments with grain sorghum were initia- ted the following year. A progress report2 was ublished in 1940 summarizing results obtained or 1937-39. On the basis of these studies, rec- mmendations included a preplanting irrigation, planting in late May or early June, irrigating just receding the booting stage and a third irrigation n 10 days to 2 weeks in very dry years. A summary of the data obtained from these arlier studies is given in Table 3. Hegari was (the variety used. No fertilizer was applied to the fine sandy loam soil which had been dryland crop- ped for more than 25 years. The four irrigation treatments used were based on fixed dates of irrigation together with the stage of crop growth. ~ Rainfall in 1937 was well distributed and to- taled 22.25 inches. A total of 16.52 inches was received in 1938 with 9.90 inches during June and iJuly ; late August and September were dry. Only 11.71 inches of precipitation were received in 1939 and rainfall was deficient throughout the growing "season; late August and September were dry and exceptionally hot. This 3-year study showed the value of irrigation in a comparatively favorable season as well as in a dry season. irrigations with June or July and August irriga- tions provided substantial increases in yield every ‘year. TABLE 2. A 44-YEAR SUMMARY OF NORMAL PRECIPITA- TION BY MONTHS. LUBBOCK STATION, 1911-54 , Average Years Tearsl Years of Month $2123., .;".:‘.**;:*.;4.. 2:25:12? Inc es percent percent percent Ianuary .53 61 11 2 ‘ February .65 7U 11 5 March .78 59 20 5 April 1.37 59 10 14 iMay 2.72 64 27 30 i lune 2.25 9f, 59 20 27 Iuly 2.03 n. 59 18 23 August 1.96 52 34 16 A September 2.60 59 14 36 October 2.18 64 5 3U ~ November .55 57 14 O December .69 64 16 0 Yearly average 18.37 Preplanting NEW MEXICO UKLAHUMA SHERMAN HANSFORD > .LIPSCOMB HUTCHIN- ROBERTS , HEMPHILL SON DKLAHUMA OLDHAM g DEAF SMITH . POTTER ‘WHEELER oonuav _. CASTRO l-swnsnsa oz , \ MOTLEY ' FLOYD $KENS ‘l _._| PARMER _.__| MITCHELL ~ l_ ' WINKLER Figure i2. Generalized soil map showing the various soil types and locations on the High Plains of Texas. A. Dalhart-Springer Soil Association (mixed land). Predominantly deep, medium and coarse-textured, moderately permeable soils such as Dalhart fine sandy loam and Springer fine sand. Pullman Soil Association (hard land 0r tight land). Predominantly deep, fine-textured, slou-‘ly permeable soils such as Pullman silty clay loam. Amarillo-Portales Soil Association (mixed land). Predominantly deep, medium-tex- tured, moderately permeable soils such as Amarillo fine sandy loams. Brownfield-Tripoli Soil Association (sandy land). Predominantly deep, coarse-textured, moderately permeable soils such as Brown- field fine sand. Occasional areas of dune sand also occur (Tivoli soils). TABLE 3. RESULTS OF GRAIN SORGHUM IRRIGATION TESTS AT THE LUBBOCK STATION. 1937-39 Irrigation - May through Oct. Total water Grain yield Grain i_ Irrigation water. Year rainfall. irrigation and per acre. acre- inches‘ inches rainfall. inches” pounds water. _q None o 1937 11s 17.6 1854 F 1938 13.5 13.5 1333 5 1939 7.9 7.9 538 Av. 13.0 13.0 1'24} 1 preplanting 3 1937 17.6 20.6 1798 1938 13.5 16.5 1618 1939 7.9 10.9 1523 Av. 13.0 16.0 1646 2 preplantings 6 1937 17.6 23.6 1915 1938 13.5 19.5 1820 1939 7.9 13.9 2201 Av. 13.0 19.0 1979 1 preplanting and 1 Iuly 6 1937 17.6 23.6 3186 1938 13.5 19.5 3248 1939 7.9 13.9 2710 Av. 13.0 19.0 3048 1 preplanting. 1 Iuly and 1 Aug. 9 1937 17.6 26.6 3371 1938 13.5 22.5 3674 1939 7.9 16.9 3293 Av. 13.0 22.0 3446 ‘Three inches of water applied per irrigation. ‘Total of all irrigation water applied and May through Octob to harvest. Further irrigation experiments with grain sorghum were conducted at Lubbock in 1953-54. Redbine-66 was the variety used. N0 fertilizer was applied to the fine sandy loam soil. In these experiments, irrigation date frequencies were studied, including various combinations of July, August and September irrigations in conjunction with a preplanting irrigation. Approximately fixed dates of irrigation were used. Nine irriga- tion treatments were replicated three times in a randomized block, Table 4. Identical amounts of irrigation Water were applied to all plots irrigated at any one date of irrigation. June through September had above normal temperatures and below normal precipitation in TABLE 4. RESULTS OF GRAIN SORGHUM IRRIGATION TESTS AT THE LUBBOCK STATION. 1953-54 er precipitation. not including changes in soil storage fro 1953 and 1954. Only 3.81 inches of rainf. received during this period in 1953 and 2.43 during 1954. Because of unusually hot, 17f sons, moisture stress was not completely‘, ted with any of the treatments used. Y ments that most adequately supplied the. requirements of the crop provided better ; Experiments at Amarillo. Irrigation experiments with grain were initiated at the Amarillo station-f Three treatments were used: a preplan ,' r gation with no further irrigation, a pre, irrigation with one irrigation after planti Ini “Hon water Total water. irrigation Grain yield Grain ' pi Irrigation g inches ' and growing season per acre. acre- w rainfall. inches pounds water. 1953 1954 1953 1954 1953 1954 1953 I None 0 0 6.5 9.8 0 1395 0 '" A Apr. ' 13.7 7.5 20.3 17.2 3580 2166 177' AB Apr.. Iuly 19.0 10.8 25.6 20.6 4708 2917 184 AC Apr.. Aug. 17.3 12.2 23.9 22.0 4268 3312 179 AD Apr.. Sept. 19.0 13.0 25.6 22.7 4169 2561 163 ABC Apr.. Iuly. Aug. 22.6 15.6 29.2 25.4 4807 3866 165 ABD Apr.. Iuly. Sept- 24.3 16.3 30.9 26.1 5640 3593 183 ACD Apr.. Aug.. Sept. 22.6 17.7 29.2 27.5 4856 3987 166 ABCD Apr.. Iuly. Aug.. Sept. 27.9 '2l.1 34.5 30.8 4905 4516 142 L.S.D. .05 366 .01 502 1953 irrigations. inches 1954 irrigations. inches A (3/5 12.2 + 6/17 1.5) 13.7 A 4/26 7.5 B 7 l0 5.3 B 7/ 13 3.4 C 8/ 3 3.6 _ C 8/2 4.7 D 9/ 4 5.3 D 8/30 5.5 Growing season rainfall 6.55 inches. Total year's precipitation 10.69 inches. 6 Growing season rainfall 9.79 inches. Total year's precipitation 13.67 inches. eplanting irrigation with two irrigations after nting. These treatments were similar t0 the »rlier experiments at Lubbock except that fixed tes of irrigation were not used. Soil moisture mples were taken throughout the season and i e planned summer irrigations were made when oisture deficiencies of about 4 inches were easured in the root zone. Each treatment was plicated three times in a randomized block. eplanting irrigations were adequate to bring he Pullman silty clay loam soil to field capacity I a depth of 6 feet. Fertilizer was not used in _ y of these studies. Unusually favorable soil moisture conditions I the spring of 1949 made a preplanting irriga- "on unnecessary. The plots were planted to the ouble Dwarf Sooner variety at 7.5 pounds per re in 38-inch rows. Except for limited irriga- 'on in recent years, the land had a 20-year history f dryland small grain and sorghum cropping. A ABLE 5. SUMMARY OF CONSUMPTIVE USE DATA. YIELD - AND WATER UTILIZATION EFFICIENCIES FOR GRAIN SORGHUM GROWN UNDER IRRIGATION. AMARILLO STATION. 1949 Irrigation Grain Grain water ap- Consump- yield yield per = 'gation plied after tive use, per acre-inch ,- planting. ‘ inches‘ acre. of water. inches pounds pounds one 0 11.6 2445 210 ne 4-inch ‘gation. ug. 16-17” 6.5 17.'2 2967 173 eplanting irrigations were not required. Total water in- . udes 8.56 inches of rainfall from planting to harvest and e decrease in soil moisture storage from planting to harvest. _ ese plots also were given a 2.5-inch irrigation the week fter planting to soften the hard surface crust which resulted I» a high-intensity rain on the day of planting. * igh-intensity rain on the day of planting caused rusting, and unfavorable stands for an irrigated rop resulted. The yields were not high but good ater utilization efficiencies were obtained, Table f. A favorable distribution of rainfall during the rowing season eliminated the need for irrigation uring July and only two irrigation treatments ere used. The 2.5-inch irrigation applied a week fter planting contributed little toward obtaining V better stand and did not provide a high irrigation efficiency. If this irrigation had not been applied t is doubtful that any appreciable difference ' ould have existed in the water utilization effi- iency of the two treatments. I A comparison of sorghum drilled in 10-inch rows with that grown in listed 38-inch rows also was made in 1-949. Early Hegari was planted at ~14 pounds per acre. Drilled sorghum increased yield approximatel 800 pounds per acre above that of row-plante sorghum, and with 3 inches less water for the season, Table 6. The 10-inch drilled plots were not cultivated and weeds were not a problem. Evaporation losses were undoubt- edly lower on these plots because the soil surface was observed to remain moist longer after irriga- TABLE 6. DRILLED (10-INCH ROW SPACING) VERSUS LIST- ED (38-INCH ROW SPACING) EARLY HEGARI ON LEVEL-BORDERED PLOTS. AMARILLO STA- TION. 1949 Water utilization Drilled Listed Number of irrigations 2 2 Inches Aug. 1-2 4.0 4.0 Aug. 24-25 2.6 3.3 Depth of water applied 6.6 7.3 Rainfall from planting to harvest 8.6 8.6 Soil moisture depletion from planting to harvest 0.1 2.4 Seasonal consumptive use 15.3 18.3 Pounds Grain yield per acre 4.010 3.169 ' (5.053? (3.395? Grain yield per acre-inch of water 262 173 ‘Actual yields on plots from which soil moisture data were obtained. tion or rainfall. The water utilization efficiencies of the listed plots of Table 6 and the August irri- gated plots of Table 5 would be expected to be about the same; however, the fact that they are identical is incidental. All of these plots were level, with no losses by runoff or deep percolation. Under these conditions the seasonal consumptive " use and the water requirement are the same. Four off-station irrigation studies with grain sorghum also were conducted on representative irrigated fields in 1949. Good irrigation practices were used but a uniform plan for the time of irri- gation of all fields was not established. Good to high yields were obtained at all locations and with a narrow range of seasonal requirements if the Tahoka field is not considered, Table 7. This range of seasonal water requirements compares closely with the consumptive use by irrigated TABLE 7. RESULTS OF IRRIGATION EXPERIMENTS WITH GRAIN SORGHUM ON THE HIGH PLAINS. 1949 Location Floydada Plainview Tahoka Hereford Soil texture Silty clay Silty clay Sandy Silty clay loam loam loam loam Irrigations after planting 3 2 2 2 Irrigation water applied after planting. inches 9.7 6.5 10.0 8.1 Rainfall. planting to harvest. inches 6.57 10.75 16.83 8.20 Soil-moisture decrease. planting to harvest. inches 0.2 negligible 0.6 3.6 Seasonal water re- quirement. inches 16.5 17.3 27.4‘ 19.9 Grain yield per acre. pounds 3.687 3.150 3.184 5.136 Grain yield per acre-inch of water. pounds 223 182 116 258 ‘There were losses by deep percolation of both rainfall and irrigation water at Tahoka; fertilizers were not used. TABLE 8. SUMMARY OF CONSUMPTIVE USE DATA. YIELD AND WATER UTILIZATION EFFICIENCIES FOR GRAIN SORGHUM GROWN UNDER IRRIGATION. AMARILLO STATION, 1950 Irrigation Grain Grain water ap- Consump- yield yield per Irrigation plied alter tive use. per acre-inch planting, inches‘ acre. of water. inches pounds pounds Preplanting irrigation only 0 16.5 1343 81 Preplanting irrigation. 1 on Aug. 18-19 4.0 18.4 1550 84 ‘A 5-inch preplanting irrigation was used. Consumptive use includes 15.62 inches of rainfall from planting to harvest and the decrease in soil moisture storage from planting to harvest. grain sorghum measured at Amarillo in 1949. Deep percolation losses of the high seasonal rain- fall and some losses of irrigation water by deep percolation greatly increased the water require- ment measured at Tahoka. Table 8 shows the results of the 1950 studies. Yields and water utilization efficiencies were low- er than expected. These studies were conducted on a field newly prepared for irrigation, which had a much longer cropping history than the field used in 1949. Martin was used and although good stands were obtained, poor yields resulted from an inadequate supply of nitrogen. The 1951 studies were conducted on the same plots as the 1949 studies. A weedy stand of sweet clover had occupied the plots in 1950. A summary of the data obtained in 1951 is given in Table 9. Greatly increased water utilization efficiencies were obtained with added irrigation in- 1951. Experiments at Tulia Studies were conducted in 1953 and 1954 on Pullman silty clay loam soils near Tulia in Swisher county. This field had a 40-year cropping history, principally winter wheat in earlier years, and grain sorghum and cotton during the last 15 years. The field had been under irrigation for 7 years and commercial fertilizer (N,P) had been applied to the 1-952 crop of cotton. Previous work indicated that fixed irrigation schedules could not be followed to obtain maxi- TABLE 10. SUMMARY OF CONSUMPTIVE USE DATA. YIELD AND WATER UTILIZATION EFI-‘ICIENCIES FOR GRAIN '11 GROWN UNDER IRRIGATION. TULIA. 1953 yNo runoff losses of rainfall or irrigation” TABLE 9. SUMMARY OF CONSUMPTIVE USE DATAQ; AND WATER UTILIZATION EFFICIENC GRAIN SORGHUM GROWN UNDER IRRIG _ AMARILLO STATION. 1951 i Irrigation Grain water ap- Consump- yield Irrigation plied after tive use. per planting. inches‘ i acre. inches pounds None 0 17.1 1510 1 irrigation. Iuly 20 4.0 20.5 21 ll 2 irrigations. Iuly 20. Aug. 13 7.5 21.9 3355 ‘Preplanting irrigations were not required. Total w“ cludes 9.38 inches oi rainiall from planting to harv the decrease in soil moisture storage from planting to 7 mum returns from the limited underground it resource. These studies incorporated four; ture levels, Tables 10 and 11. Each tre" included the use of a preplanting irrigati was replicated three times in a randomizedj were experienced from the level plots used. Consumptive use values in Table 11 incl -_ inch available water in the soil at the time? plying a 6.5-inch preplanting irrigation of April, 3.77 inches of further rainfall before ’__ ing and 3.33 inches of rain during the . season, a total of 14.5 inches. At planti soil profile was at field capacity to a depth inches throughout the field and to 72 inc many sampling points. The 72-inch prof” tained the following amounts of available? ture at harvest which were subtracted: tre_ A-0 inch; treatment B—5.4 inches; t -: C—4.2 inches; and treatment D—6.0 inc ' Redbine-66 was planted in 40-inch spaced? Fertilizer was not used in either 1953 i?- but a fertilizer test with irrigated grain was conducted at the same location? 4 i The 1953 season was the hottest and d ' record for most vicinities on the High Plains‘ land crops failed in nearly all localities ‘ 2.71 inches of rainfall were measured fro’; ing to harvest in Tulia. Yields of over, pounds of grain were obtained in these with treatments including three and four a tions after planting. l Irrigations ~ . - - - _' Irrigation after ‘planting Sgfigglhfge Ggglzzlzld 6:1,‘: F’ Number Inches .' pounds water. p, A — Preplanting only 0 0 12.7 1110 B — Irrigation before 75% available water is 1g exhausted from 0 to 24-inch depth to 9-15 3 10.9 23.6 5205 ~ _ C — Irrigation before 50°/,, available water is V "a exhausted from 0 to 24-inch depth to 9-1 3 10.5 23.2 _ 4230 D —- Irrigation before 50% available water is _ exhausted from 0 to 24-inch depth to 9-15 4 14.1 26.8 5210 L.S.D. .05 52 .01 79 ‘Including 2.71 inches rainfall from planting to end of growing season. 8 re 3. Grain sorghum on plot with above 25 percent fcilable moisture maintained in the 0 to 24-inch depth til September 15. Tulia, September 29. 1953. The preplanting only treatment (treatment ,9 produced grain but with a much lower water ilization efficiency. The highest water utiliza- tn efficiency in 1953 was obtained when 25 rcent available moisture level was maintained in 3 0 to 24-inch depth (treatment B). Plants ceiving this particular treatment were stressed t water because of high temperature early in i season. They bloomed about a week later c. had somewhat heavier heads of grain than nts in the other two treatments receiving mmer irrigations. This condition did not occur ain in 1954 with the same treatments. Plants fl each of the three irrigation treatments receiv- lg summer irrigations in 1953 are shown in Fig- es 3, 4 and 5. Growth was excellent on all of e three treatments. .However, a reduced yield psulted when the September irrigation was with- ield. The reduction in yield was attributed to a ick of available moisture within the 0 to 24-inch il depth through September'15. No rainfall was ceived in August or September. A comparison of the available moisture in torage during the 1953 season with 50 percent epth until September 15 (treatment D) and a replanting irrigation only (treatment A) is hown in Figure 6. Rains contributed to the vailable moisture in storage only once during the eason. Water use by the plants receiving only preplanting irrigation was greatly reduced in rly August because of lack of available mois- ure. GROWN UNDER IRRIGATION. TULIA. 1954 vailable moisture maintained in the 0 to 24-inch _ Figure 4. Grain sorghum on plot with above 50 percent available moisture maintained in the 0 to 24-inch depth until September 1. Tulia, September 29. 1953. The 1954 season was similar to the 1953 sea- son. Dryland crops failed in the Tulia vicinity. Lower yields were obtained in 1954 than in 1953 because of a nitrogen deficiency. Plots in another experiment that received 8O pounds of nitrogen, sidedressed at planting, yielded 5,340 pounds of grain per acre when maintained at 50 percent available moisture in the 0 to 24-inch depth until September 15 (treatment D).‘ The sorghum in Figure 7' received a preplant- ing irrigation but had not been irrigated since planting. These plants had received less than 1 inch of rain by July 28, 1954. Figure 8 shows sorghum grown under identical conditions except Figure 5. Grain sorghum on plot with above 50 percent available moisture maintained in the 0 to 24-inch depth until September 15. Tulia, September 29. 1953. ‘ABLE 11. SUMMARY OF CONSUMPTIVE USE. YIELD AND WATER UTILIZATION EFFICIENCY DATA FOR GRAIN SORGHUM Irrigations _ Grain yield Grain yield per Irrigation after planting Cmlslfmpllve per acre. acre-inch of Number Inches 1159' males pounds water. pounds " — Preplanting only .. 0 0 14.5 1283 88.5 i1 — Irrigation belore 75 o available water is exhausted from 0 to 4-inch depth to 9-15 3 12.0 21.1 2828 134.0 ‘l —- Irrigation beiore 50°/° available water is exhausted from 0 to 24-inch depth to 9-1 11.0 21.3 2993 140.5 i! — Irrigation before 50% available water is exhausted from 0 to '24-inch depth to 9-15 4 15.0 23.5 3173 135.0 Ii S.D. .05 672 .01 1018 INCHES OF WATER Available moisture Planted June H \ Harvested October 20 INCHES AVAILABLE WATER b b I I Irrigation: Rain to I Rain o . l| Quorum: | JULY_ I AUGUST lSEPTEMBERl ocroeen ] ——- Treatment A. Preplanting irrigation only —-— Treatment D. Maintain 50% available moisture in Oto 24-inch depth to 9/ I5 Figure 6. Available water in storage, irrigation water ap- plied and rainiall with grain sorghum on Pullman silty clay loam. Tulia. 1953. that a 4-inch irrigation was applied 0n July 21 before the available soil moisture in the 0 to 24- inch depth was depleted to 25 percent of storage capacity. Water Requirements The Water requirement of grain sorghum is not a fixed value. In hot, dry years transpiration by the plant is higher than in cool, relatively humid seasons. Low relative humidities, high temperatures and Wind movement also increase evaporation from the soil surface, adding further to the consumptive use. Other factors also can cause important differences in consumptive use and Water requirement. Restricted soil moisture reduces transpiration. Frequent irrigation in- TABLE 12. WATER REQUIREMENTS FOR GRAIN SORGHUMS AT vnnrous LOCATIONS ON THE HIGH PLAINS. 1949-51}; creases evaporation. Unavoidable runoff of fall and irrigation water or loss by deep tion increases the water requirement. " Water used for crop growth may be s =Q to the soil by precipitation or irrigation du , before the period of crop growth. Water determined in these studies by measurii amount of available water in the soil at p time or at the time of the preplanting irrii adding the rainfall and irrigations applied ~- the season and subtracting the amount ofigl able Water in the soil at harvest. The bal the Water required to produce the crop. v mary of the water requirements of grain so at various locations on the High Plains for; year period, 1949-51, 1953-54, is presen '1 Table 12. g In favorable years, such as 1949, the wa quirement of high-yielding grain sorghu, been as low as 16 to 18 inches of water. . g dry years, such as 1953 and 1954, 24 inc water were required to produce a maximum Water Management Irrigation Water and rainfall are equally? able for crop production. An additional ac, of rainfall utilized is an acre-inch of ir water saved for a later irrigation applicati e most years rainfall provides half the wa, quirement of grain sorghum. The final m of efficient water use by‘ the crop is in the i‘; of grain obtained per acre-inch of water.“- Water rather than land is limited, the _ possible yield per acre, irrespective of wat is not necessarily the most profitable. The" est return per acre-inch of water .has been i; ed by providing adequate amounts of was vigorous crop growth throughout the sea’ plants adequately supplied with the necessa trients. Consumptive Use Water use by the grain sorghum plant with germination but is comparatively i; the first 2 or 3 weeks of development, ave i . Rainiall. planting Irrigation applied Soil moisture storage Water requir Year Locahon to harvest. inches after planting. inches decrease. inches‘ inches 1949 Floydada 6.57 9.74 0.19 16.50", Plainview 10.75 6.50 0 17.25 Tahokai 16.83 10.00 0.60 27.43? Hereford 8.20 8.03 3.63 18.86 i. Amarillo 8.56 6.54 2.09 17.19 Amarillo 8.56 7.12 2.35 18.33 i, Amarillo“ 8.56 6.72 0.10 15.40 1950 Amarillo 15.62 4.00 1.20 18.42 » 1951 Amarillo i 9.38 7.53 5.03 21.94 1953 Tulia 2.71 14.10 ' 9.00 26.80 ' 2.71 11.90 . 9.00 23.6 1954 Tulia 3.33 15.00 6.10 23.50 ‘Available water in storage at planting minus available water in storage at harvest. 2Losses due to deep percolation of heavy rainfall following irrigation. “Drilled in 10-inch spaced rows. l0 0.05 to 0.10 inch per day. Irrigation should ‘t be necessary during this time even through riods of drouth, except for sandy soils with low a ter-holding capacities. D ail y water u s e rough July, August and early September aver- es about 0.25 inch. 1 The year-to-year variation in the use of water grain sorghum at several locations by 10-day riods is shown in Figure 9. The 1950 growing J son was considered favorable and moisture use p. not reach an average of .25 inch per day dur- lg any of the 10-day periods. a There were no rains from planting until late ly in 1953. Evaporation losses from the soil rface during June and July were low and con- mptive use during the early stages of crop g wth was low. Record high temperatures, evap- _ation following irrigation and increased trans- ation provided extremely high water use dur- fg the latter part of July and August despite me relief provided by rains during July 18 to 21. ne and July in 1954 were similar to 1953 except at small rains permitted greater evaporation sses which increased consumptive use. High mperatures in July and August 1954 again pro- ded very high consumptive use, but a signifi- i: decrease was obtained in early August from veral days of cool weather. eplanting Irrigations Preplanting irrigations should be made to pro- 'de field capacity storage to a depth of 5 or 6 et if the soil profile-is that deep. Ten to 12 ches of irrigation water should be applied to - llman silty clay loam soil, which has little avail- le water in the profile. Amarillo and Lubbock _ ation weather records show that preplanting rigations are needed 2 years out of 3 to bring e soil to field capacity. Precipitation fails to lmoisten the soil surface by planting time in only year out of 20 following an early preplanting il at Amarillo. Precipitation fails to remoisten i. e surface soil for planting in less than 1 year out 7 when winter preplanting irrigations are used t Lubbock. requency of Irrigation p Rainfall usually provides half the water re- uirement of grain sorghum, but it is too unde- ndable to eliminate the need for planning each i: igation in the water-management program. rrigation may be delayed a few days and the ecessary depth of application decreased follow- ‘ g an effective and timely rain at any time dur- p, g most seasons. Rains seldom are adequate to rovide for consumptive use for a 2-week period uring the irrigation season and thus completely liminate an irrigation. Less than 10 percent of rains during the growing season at Amarillo j; e 1 inch or more. Only one rain in excess of 1 ch can be expected during July and August at marillo. Monthly rainfall totaling 3 inches or , ore in. any 1 month during the growing season rigation and subsequent drying of the surface l Figure 7. Sorghum that did not receive irrigation after plant- ing was in severe stress by late Iuly. All plots received a preplanting irrigation. Tulia, Iuly 28, 1954 occurs in less than 1 year out of 3 at the Lubbock station. Runoff should be controlled so that the bigger rains expected during a season can be utilized more effectively. A theory has existed that if sorghum is put in stress for water a deeper root system is pro- duced. Another similar idea has been that “it doesn’t hurt sorghum to wait for water.” Both are without basis. At no time in the 5 years of studies, 1949-51, 1953-54, was there any evidence that sorghum plants in stress for moisture pro- duced better or deeper root systems. More water may have remained in the soil profile on plots re- ceiving additional irrigation, but the use of sub- soil moisture was as great or greater by plants maintained with constantly adequate supplies of available moisture. Plants once in severe stress for moisture never produced as much grain as plants not in stress even though rainfall and later irrigation provided enough moisture to grow a plant of normal size. An adequate and continuous supply of available soil moisture must be main- tained to produce the greatest return per acre- inch of water. Figure 8. Sorghum plants that received the first irrigation following planting Iuly 21. when available moisture in the 0 to 24-inch depth decreased to 25 percent, made rapid growth during the following week. Tulia, Iuly 28. 1954. I1 If fertilizer is used, an earlier irrigation may be required to make the fertilizer available t0 the plants. The successful use of fertilizer re- quires adequate moisture throughout the season. Studies show that where nutrients are limited, the use of fertilizer provides a higher return of grain per acre-inch of waterf‘ - In extremely hot weather small sorghum plants wilt and appear to need water even though ample supplies of moisture are available in the soil within 6 or 8 inches of the surface. An irri- gation usually relieves this condition, probably by the cooling effect rather than by providing addi- tional water to the plant. Generally, it is not possible to irrigate large acreages of the crop dur- ing this stage of development and no data are available to indicate the economic value of such irrigations. The first irrigation should be planned about 3 weeks after planting if rainfall has not replen- ished an appreciable portion of the 2 to 3 inches of water used by the sorghum crop and lost by evaporation. At this stage of growth some avail- able moisture should be maintained in the sur- face foot of soil. On the Pullman soils the read- ily available moisture in the 0 to 24-inch depth should be maintained above 50 percent of storage capacity. After this time, irrigation will be re- quired at 10 to 14-day intervals until after bloom- ing whenever rainfall is inadequate to maintain 25 to 50 percent available water in the 0 to 24- inch depth of soil. Sandy soils or shallow soils require more frequent applications. Extremely high temperatures may require more frequent irrigations. In late July, August and September, the crop extracts water from depths below 3 feet. Except on the sandier soils it often is not practical to re- fill these depths during the growing season. Us- ually the available water at these depths isf quate to meet the withdrawal by the sore crop for the entire season without replenish An adequate preplanting irrigation to brin entire rooting depth of the soil to field w’ is important if the moisture storage capaci plant nutrients of the emtire profile are p utilized. l?» In most seasons two irrigations after are adequate for sorghum if the potentiali zone is near field capacity at planting time. ing of irrigations cannot be predicted, v? nearly every year there is a period of inad = l rainfall and a soil-moisture deficiency in late? requiring an irrigation at or before that ,3 Usually applications of 3.5 to 4.0 inches are>f quate for the growing crop on clay or loam 1 with 2.0 to 2.5 inches per application on extre sandy soils. More frequent irrigation is req on a sandy soil. Except for late-planted crops, irrigation iii August or the first several days of Septem" as late as additional water benefits a pro‘ irrigated grain sorghum crop. If it is desi provide moisture in storage for a succeeding later or heavier irrigations may be applied. ghum plants continue to use water after mat i until frost at the rate of about 0.08 inch day. With an early harvested crop it migh, possible to save 2 inches of water or more ; field were tilled to kill “the plants a month frost. T'he wind erosion hazard should be sidered in connection with fall tillage of sorg. stubble. An irrigation should be started early enou that the last plants irrigated will not have‘. fered for moisture. This often makes it desi to increase the amount of water applied at? first irrigation. A 2-inch irrigation may be p a ' 4 ? a- 3 — _" ‘l’ "r 3 _ U- m Figure 9. Consumptive v- __ F‘ water by 10-day 5 gram sorghum. The 5 ...- and August 31 data ' _' , cluded in the last IO-cl K riod of the respective -- ?$$?$$$ss$s2 sssssssssss esssssssssss -_---__-I_'.-'_i -'-.'...L.'_-L.'_-LL -'-_',.'_.'_'l.'_'|.'..l' - cu - : N - m - o: - N — N - w _ I T‘ = 5 I E JUNE JULY AUGUST SEPT JUNE JULY AUGUST SEPT. JUNE JULYN AUGUST S PT. Amarillo — I950 Tulio- I953 Tulia - I954 12 uate to replenish the soil-moisture deficit when i ch an irrigation is started. An increased depth if application should be provided on each succes- 've day to provide for the added consumptive Else. If 10 days are required to irrigate the crop i reage, an application of 4 inches or more may required to replenish the" soil-moisture deficit n those portions of the field irrigated near the nth day. Usually the next irrigation follows at nearly uniform time interval and the soil-mois- ure deficit is approximately the same on each rt of the field when it is irrigated. A uniform epth of water can be applied throughout the . ollowing irrigation unless substantial amounts of iainfall are received. pth of Application The depth of water to be applied at an irriga- 'on depends on the moisture content and storage pacity of the soil. Enough water should be pplied to replenish the moisture deficit in the Oot zone or to obtain field capacity to a desired epth. Soil moisture should be determined for l ost effective irrigation. Experience, together 'th the use of a sharpshooter, soil tube or soil uger, are valuable for determining depths of ~ ater penetration and estimating moisture con- I nt, Figure 10. Over-irrigation wastes valuable water and time and is detrimental to the crop. ight irrigations have to be applied more fre- uently and have higher evaporation losses and bor costs. See your local Extension Service or oil Conservation Service personnel for assistance in estimating moisture conditions in the: soils on your farm. . A soil must store water as well as supply nu- _ trients for optimum grain sorghum production. Studies show that in most years sorghum plants extract water from depths of 5 to 6 feet. A soil istoring 2 inches of water per foot of depth stores twice as much water in the same depth as a soil storing only 1 inch per foot of depth, and requires i less frequent irrigations during dry periods. A Efficiency of Water Use The greatest return per acre-inch of water is obtained from a crop sufficiently supplied with nutrients and given an adequate supply of avail- able moisture from planting to the soft dough stage. A return of 200 pounds or more of grain t per acre-inch of water may be expected in most years When the crop is not damaged by hail or other uncontrollable factors. “Stretching” the A irrigation supply over more acres may guarantee g a crop, but unless rainfall in conjunction with limited irrigation actually meet the optimum wa- ; ter requirements of,.the crop, a reduced return per , acre-inch of water»; results. Since the monthly rainfall is below average in about 60 percent of " the months, depending on rainfall is a poor risk. Efficient water use also depends on delivery c i? of equal and adequate amounts of water to all of the plants in the field. Methods of Irrigation The main requirement of an irrigation for the crop is to deliver the amount of water needed to the root zone of each plant. This requires good distribution. It is desirable to apply little more water than the root zones require and to lose as little as possible by runoff. This involves appli- cation efficiency. No other single factor .has lowered the overall yields of grain sorghum fields on the Texas High Plains more than poor distri- bution of irrigation water. Graded furrows are the most common means of irrigating sorghum on the High Plains. Satis- factory irrigation. efficiencies and good distribu- tion can be obtained by using the correct length of run and a size of furrow streams suited to soil conditions. Utilizing irrigation streams that are too large may cause erosion. Some irrigation water will leave the field as runoff with graded furrow irrigation. This runoff should not exceed 1O percent of the amount of water applied. Run- off water can be used for irrigating lower fields; centrifugal pumps have been used to lift it into another ditch for delivery to higher ground. No Figure 1U. Some equipment for obtaining soil samples to estimate available moisture includes an orchard auger. soil auger with soil tube attachment and a sharpshooter. 13 control of rainfall is provided with the graded- furrow system of irrigation. Runoff starts when the intensity of the rain- fall exceeds the water intake of the soil. This runoff is cumulative in that it increases as it proceeds down the furrow. A rain that exceeds soil intake by 1 inch for a duration of 1 hour would produce an average runoff approaching 1 cubic foot per second or 450 gallons per minute per acre of land. If a 20-acre field drained at one cor- ner under such conditions, a runoff flow of 20 cubic feet per second or 9,000 gallons per minute might be attained. This explains the erosion frequently noted along the lower ends of many fields following rain storms. Erosion alone is not the only loss. An inch of rainfall lost by runoff is the inch of water that could have been left stored in the soil following evaporation from the surface had that water remained on the field. The rains that really count run off too often. Level furrows provide high irrigation applica- tion efficiencies and excellent distribution of wa- ter. There are no losses of irrigation water by runoff and often it is not necessary to cut back the furrow streams. Rainfall stays where it falls and runoff occurs only with infrequent heavy rains every few years. Good engineering and careful land leveling are required for level-furrow irriga- tion. Planting in the bed or in a modified bed is de- sirable with either graded or level-furrow irriga- tion. This system of planting provides the best furrow cross section for early irrigation as well as an adequate furrow for conveying water throughout the season. Although planting in the furrow is the method used most on the High Plains, experiments at the Lubbock station show that better stands of sorghum are obtained by planting on the level or in a modified ridge. The seed are placed in soil where lower temperatures exist and stands may be lost by puddling and crust- ing of the soil in the furrow by rainfall before emergence of the plants. 14 Graded border strips also can be ut' irrigating sorghums. Graded borders I? corrugated to provide better water cont i, gation of graded borders should be simil of graded furrows. Problems of contro . gation runoff and water distribution 1‘ considered as there is no effective cont ~{ off from rainfall. Level borders have been used for the, tion of sorghum on the Amarillo sta f 1949. Irrigation is simple and very high, cies are obtained with excellent water f ton. Narrow row spacings, just wide permit cultivation, can be used. Narro" ings, 10 inches at Amarillo, can be used, " border ridges being planted but not v__ Sprinkler irrigation is an efficient t! water application on soils that have 1, intake rates. This method is commonly; the Brownfield, Lamesa and Seminole i on sandy soils. * Acknowledgment These investigations were conducted tively by the Texas Agricultural Experi tion and the Soil'and Water Conservl) search Branch, Agricultural Research U. S. Department of Agriculture. ‘ Literature Cited 1. Characteristics of rainfall distribution and: producing storms at Amarillo, Texas. M. é Unpublished report. ' v» 2. Pump irrigation studies on the South Jones and Frank Gaines. Tex. Agr. Exp; 667 (1940). 3. Grain sorghum fertilizer trials, High Plains 1953. D. L. Jones and John Box. Tex. Agr. PR 1700 (1954). '-‘ 4. Grain sorghum fertilizer trials, High Plains, 1954. E. L. Thaxton, Jr., D. L. Jones and‘ Tex. Agr. Exp. Sta. PR 1789 (1955). [Blank Page in Original Bulletin] 3k State-wide Researc i’ The Texas Agricultural Experiment St - is the public agricultural research age Location of field research units in Texas main- oi the State oi Texas‘ and is one of ' l ta'ned by the Texas Agricultural Experiment Stiztion and cooperating agencies parts oi the Texas A6=M College Syst , IN THE MAIN STATION, with headquarters at College Station, are 16 subject-matter departments, ‘A departments, 5 regulatory services and the administrative staff. Located out in the major agricultuti of Texas are 21 substations and 9 field laboratories. In addition, there are 14 cooperating stations by other agencies, including the Texas Forest Service; the Game and Fish Commission of Texas, Prison System, the U. S. Department of Agriculture, University of Texas, Texas Technological Coll the King; Ranch. Some experiments are conducted on farms and ranches and in rural homes. RESEARCH BY THE TEXAS STATION is organized by programs and projects. A program of resear sents a coordinated effort to solve the many problems relating to a common objective or situation.‘ search project represents the procedures for attacking a specific problem within a program. THE TEXAS STATION is conducting about 550 active research projects, grouped in 25 programs w, clude all phases of agriculture in Texas. Among these are: conservation and improvement of so servation and use of water in agriculture; grasses and legumes for pastures, ranges, hay, conserva improvement’ of soils; grain crops; cotton and other fiber crops; vegetable crops; citrus and other st cal fruits; fruits and nuts; oil seed crops—other than cotton; ornamental plants—including turf; b _j weeds; insects; plant diseases; beef cattle; dairy cattle; sheep and goats; swine; chickens and tut‘ mal diseases and parasites; fish and game on farms and ranches; farm and ranch engineering; f j ranch business; marketing agricultural products; rural home economics; and rural agricultural ; = Two additional programs are maintenance and upkeep, and central services. V RESEARCH RESULTS are carried to Texas farm and ranch owners and homemakers by specialists any agents of the Texas Agricultural Extension Service. '