8-993 SEPTEMBER I962 I I nfluence of Cropping Systems I n Cotton and Corn Yields n the Gulf Coast Prairie "w -' - y ‘~~‘ ._a ~ ‘i. " THE AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS TEXASIAGRICULTURAL EXPERIMENT STATION R. D. LEWIS. DIRECTOR, COLLEGE STATION, TEXAS S UMMAR Y Experiments were conducted during 1953-58 0n (l) the influence of cropping systems on the Gulf Coast Prairie on crop yields, soil improvement and conservation; (2) the influence of nitrogen fertilizer on crop yields and (3) fertilizer tests on continuous and rotated cotton. Cropping systems producing the highest forage yields, with and without nitrogen fertilizer, were those which contained a legume. A 2-year system, the first-year oats and Sudan- grass and the second-year cotton, produced the low- est forage yield of any system tested and showed little effect on soil improvement. High forage yields were obtained from all crop- ping systems containing Hubam. A 3-year system of first-year oats-Hubam, Sudan; second-year Hubam, Sudan and third-year cotton provided forage over a long period of time. The year this system was in cotton, the land was easier to work, there were not as many weeds and better stands of cotton were obtained. The main disadvantage of this system was that two planting operations a year were re- quired. Cropping systems containing Dallisgrass and White clover are more highly recommended than all other systems tested. These forage crops furnished year-round grazing and required only one planting operation per cycle of the cropping system. The disadvantages of these forage crops are: (1) a good seedbed is necessary to obtain a good stand of Dallis- grass; (2) White clover can cause bloat in cattle; (3) 2 years are needed to obtain high forage yields and (4) it is difficult to obtain a good seedbed for corn or cotton when the land goes out of forage production. Dallisgrass and White clover produced higher forage yields and were better able to utilize nitrogen fertilizer following cotton than when following corn. Fescuegrass, in a 5-year cropping system of 3 years fescuegrass and 2 years cotton, produced winter and spring grazing, high forage yields the first year in the system when treated with nitrogen fertilizer, and required only one planting operation. This sys- tem, however, was the most unsatisfactory system tested, because it was difficult to maintain a good stand of fescuegrass and low yields were produced without nitrogen fertilizer. In preparing the land for cotton, the plots coming out of fescuegrass were more difficult to work, and poorer stands of cotton were obtained than in any other system tested. Statistical analysis showed that there were no significant differences in cotton yields because of the treatments in 1953. In 1954 nitrogen fertilizer produced a highly significant difference in the in- crease in yields and in 1955 a significant difference was caused by the interaction of nitrogen and cro rotation. In 1956 the effects of cropping syste became apparent in increased yields. In 1956-5 there was a highly significant increase in yields b cause of crop rotation, and in. 1957 a highly signif' cant increase in yields because!‘ of nitrogen fertilize The three cropping systems recommended for th Gulf Coast Prairie are: (1) a 5-year system of 3 yea Dallisgrass-White clover and 2 years cotton; (2) 3-year system of first year oats, Hubam, Sudanj se ond year Hubam, Sudan and third year cotton; (3 a 2-year system of first year Hubam, Sudan and w ond year cotton. Applications of 60 pounds of nitrogen per acr per year produced an average increase in cotto yields in all systems tested. In comparing the fertilizer tests on continuo cotton and cotton rotated with Dallisgrass and Whit clover, the nonfertilized, rotated cotton produc an average yield increase of 550 pounds of se cotton per acre per year more than the nonfertiliz continuous cotton. In the fertilizer test on continuous cotton, n. highest average increase in yield was produced t p the 90-30-60 treatment. This treatment produc 380 pounds of seed cotton per acre more than t nonfertilized cotton. The second highest increa was obtained from a 45-0-0 treatment, which pr duced an average increase of 190 pounds of se cotton per acre. In the fertilizer tests there was a larger increa in yield of rotated cotton with fertilizer than in i. continuous cotton. In the fertilizer test on rotat cotton, nitrogen was the most effective element a phosphorus the next in increasing cotton yields. F tilizer applications of 90-30-0 and 45-30-0 produc the highest yields with an average of 1,430 and 1,3 pounds of seed cotton per acre per year, respectivel A 5-year system of 3 years Dallisgrass and Whi clover and 2 years corn increased first and seco year corn yields 42 and 56 percent more than t continuous corn. When nitrogen fertilizer was a plied, there was an increase in yields of 21 and l percent more than the fertilized, continuous co The application of 60 pounds of nitrogen increas ' Combinatio g continuous corn yields 60 percent. of crop rotation and nitrogen increased first a second year corn yields 96 and 88 percent more th the nonfertilized continuous corn. Cropping systems of Dallisgrass and White clov are recommended as soil improvement crops for co as well as cotton. - A deficiency of soil moisture was a major limiti factor in cotton and corn yields during this exp mental period. Con tents Acknowledgments ...................................................................................................................................... __ 23 _ mmary ........................................ ........................................................................................................... .. 2 l, introduction ............................................................................................................................................... . . 5 I limate and Rainfall ............................................................................................................................... .. 5 il Type .................................................................................................................................................... -- 5 xperimental Plan .................................................................................................................................... -_ 5- ' Objectives ............................................................................................................................................. ._ 5 ,_ Field Design ............................................................................................................ ........................ -- 5 fertilizer Treatments ............................................................................................................................... .- 6 _ rops ............................................................................................... _._. ......................................................... .. 6 5" Oats ....................................................................................................................................................... .. 7 Gulf Ryegrass ............................................................................................ ..................... .......... .., .... .. 7 Sudangrass ............................................................................................................................................ .- 7 Dallisgrass ............................................................................................................................................. .. 7 Fescuegrass ........................................................................................................................................... -- 7 White Clover ....................................................................................................................................... .. 8 Hubam Sweetclover ................................................................. ....................................................... -- 8 Israel Sweetclover ............................................................................................................................... -- 8 Cotton ................................................................................................................................................... .. 8 Corn .............................................. .; ........................................................................ ..- ............................ .. 8 “Cropping Systems ..................................................... ............................................................................ .- 9 Continuous Cotton ............................................................................................................................. -- 9 Oats, Sudangrass; Cotton ................................................................. ................................................ ._ 9 Hubam, Sudangrass; Cotton ............................................................................................................. .. 9 Oats-Hubam, Sudangrass; Hubam, Sudangrass; Cotton ............................................................. .. 9 ,2 p Dallisgrass-White Clover, 2 Years; Cotton, 1 Year ....................................................................... .. 9 * Dallisgrass-White Clover, 3 years; Cotton, 2 Years ................................................................... _. 9 Fescuegrass, 3 years; Cotton, 2 Years ............................................................................................. .. 9 Continuous Corn ................................................................................................................................ .. 9 Dallisgrass-White Clover, 3 Years; Corn, 2 Years ......................................................................... _. 9 Management Practices ............................................................................................................................ -- 9 I Forage Crops ........ Q .............................................................................. ..; ............................................ .. 9 Row Crops ........................................................................................................................................... -_ l0 Effects of Nitrogen Fertilizer on Forage Yields ................................................................................. .. l1 Forage Crops Recommended for Cropping Systems Containing Cotton and Corn .................. .. 12 Oats, Sudangrass; Cotton .................................................................................................................. .- 12 Hubam, Sudangrass; Cotton ............................................................................................................ -_ 12 Oats~Hubam, Sudangrass; Hubam, Sudangrass; Cotton ............................................................. ._ 12 Dallisgrass-White Clover, 2 Years; Cotton l Year ....................................................................... __ 13 Dallisgrass-White Clover, 3 Years; Cotton or Corn, 2 Years .................................................... -- 13 t , Fescuegrass, 3 Years; Cotton, 2 Years .............................................................................................. .- 13 I Influence of Cotton and Corn on the Yields of Dallisgrass-White Clover .............................. ._ 14 l, Influence of Cropping Systems on Cotton Yields ............................................................................. -- l4 ‘ Cotton Yields, 1953-57 ....................................................................................................................... .. 14 No Nitrogen .................................................................................................................................. -. l6 Nitrogen ......................................................................................................................................... .. 17 Effects of Nitrogen on Cotton Yields ........................................................ -._. ................................... __ 17 Cropping Systems Recommended for Cotton ............................................................................. _. 18 Cotton Fertilizer Tests ...................................................................................................................... __ l9 Continuous Cotton ............................................................................................. _; ....................... __ 19 Rotated Cotton ............................................................................................................................. __ 20 Influence of pallisgrass-White Clover and Nitrogen Fertilizer on Corn Yields ........................ __ 21 Corn Yields .......................................................................................................................................... __ 21 Crop Rotation ............................................................................................................................... __ 22 Nitrogen Fertilizer ........................................................................................... ........................... __ 22 Recommendations for the Gulf Coast Prairie ...... ...................................................................... __‘ 22 Literature Cited ......................................................................................... ............................................. __ 23 Figure ‘l. The Gulf Coast Prairie Region of Texus. _ NT YEARS ROTATION, one of the oldest funda- entals 0f crop production, has been challenged nycrop specialists and farmers. Rotation, ac- “ to some workers, has become a liability in- fof an asset. Members of this group contend that (f farmer wants to get maximum economic pro- 1 from his land, he must plant the maximum value crops every year. This idea has some 'cation, since a single set of soil management es can be applied to the land. These manage- j practices require less farm machinery and lower production costs. With the expanded use of __ers, yields have been maintained at a fairly Zlevel. nfortunately with the passage of time, crop p. have shown a gradual decline. This decline L» that no single system-of soil management will soils and produce economic returns to farmers. <- e of crop surpluses, acreage controls and de- 2ft yields, farmers and research workers have a closer and more critical look at rotations. need for additional cash income has led to the uction of the beef cattle enterprise into the ‘g systems on the Gulf Coast Prairie of Texas, l. This has led to the problem of finding ing systems which will produce the most eco- ‘Tm returns by increasing cash crop yields and cing adequate forage yields for beef cattle ~. ction. CLIMATE AND RAINFALL i‘ e Gulf Coast Prairie is generally favored with ‘vely low summer temperatures and abundant g ll. The average annual rainfall at Angleton f 45-year period, 1914-58, is 47.46 inches, Table ainfall is fairly uniform throughout the year, gh it may be quite variable within any given The rate of evaporation varies considerably, ‘(the climate is characterized by wet winters and i: uth during the summer. The average growing 1 from the last iglcilling frost in the spring, Cary 22, to the first killing frost in the fall, Lian 2, LS days. w tively, assistant agronomist and superintendent, Sub- A.‘ No. 3, Angleton, Texas; and associate professor, Depart- ,‘ of “Soil and Crop Sciences, College Station, Texas. luence of Cropping Systems on Cotton and 1i Corn Yields on the Gulf Coast Prairie B. E. Jefer, J. C. Smith and E. L. WhiteIey* SOIL TYPE The Gulf Coast Prairie includes some 8 million acres of dark colored soils with black to gray clays and some sandy loams. The main soil series are Lake Charles, Beaumont, Harris, Hockley, Katy and Edna (4). The Lake Charles clay was selected for this study because it is the most extensive and important soil in the area. It is a dark ashy-gray or black clay, which is slowly permeable to rainfall. Drainage is poor, and planting is retarded sometimes by excessive rains during the spring. The soil is very sticky when wet, but when dry, the soil in cultivated fields crumbles and in uncultivated areas cracks deeply. Normally, the soil pH is neutral with a range of 6.5 to 6.8; native soils are medium to high in nitrogen, low to very low in phosphorus and medium to high in potassium (4). EXPERIMENTAL PLAN This bulletin is a report on an experiment begun in 1953 on the influence of cropping systems on the Gulf Coast Prairie on crop yields, soil improvement and conservation. The research was conducted at Substation No. 3, Angleton. Obiecfives The main objectives of the project were (l) to determine the effects of certain cropping systems on soil productivity on Lake Charles clay; (2) to obtain information which can be used in formulating good cropping systems; (3) to derive methods where- by soil productivity may be maintained for given soil and land conditions; (4) to determine the effects of good cropping systems on soil structure and air- water relationships and (5) to determine the com- bined effects of known positive practices on crop production. Field Design This test was conducted on an area of Lake Charles clay soil that had been in cultivation for at least 5O years. The experimental design was a split plot random- ized block, replicated three times. The cropping 5 TABLE 1. MONTHLY AND ANNUAL PRECIPITATION AT ANGLETON, 1953-58 AND THE 45-YEAR AVERAGE, 1914-58 Average Month 1953 1954 1955 1956 1957 1958 1953-58 45-year January 0.65 0.98 4.42 3.26 1.93 7.05 3.05 3.49 February 4.96 0.18 5.47 4.05 3.24 4.37 3.71 3.17 March 0.08 1.05 0.36 1.36 10.23 1.51 2.43 3.31 April 0.52 1.91 5.06 2.76 4.54 2.01 2.80 3.23 May 10.08 2.25 4.84 1.73 2.62 3.39 4.15 3.96 June 4.88 2.73 2.55 1.15 7.29 0.25 3.14 3.78 July 3.82 1.73 3.40 2.23 0.16 3.56 2.48 5.02 August 13.58 1.11 6.00 1.50 2.33 3.81 4.72 4.52 September 0.80 1.84 3.60 0.58 9.97 19.49 6.05 5.07 October 3.69 3.81 0.32 4.24 5.09 2.21 3.23 3.276 November 5.68 1.71 0.56 1.82 7.90 1.33 3.17 32:70 December 3.90 2.46 3.45 5.05 1.94 3.16 3.33 4.42 Total rainfall 52.64 21.76 40.03 29.73 57.24 52.14 Average annual rainfall 48.37 47.72 47.54 47.13 47.36 47.46 Departure from average + 4.27 —- 25.96 -— 7.51 -— 17.40 + 9.88 —|- 4.68 systems used in this study were selected to give the maximum range in soil improving practices, Table 2. Cotton and corn were used as index crops to measure the effects of the different practices included in the tests. The selection of grasses and clovers used in the cropping systems was based on experiments conducted since 1914 at the Angleton station. These earlier tests indicate that oats, Sudan, fescue and Dallisgrass are the best grasses for the area and that Hubam and Louisiana S-1 White clover are the best legumes. Each crop in each system appeared every year during the study. An additional 3x2 factorial fertilizer test with three replications was carried out at the same time as TABLE 2. CROPPING SYSTEMS USED IN THE TEST AT ANGLETON, 1953-58 Year in System no. system Cropping system 1. Continuous cotton 2 1st Oats, Sudan 2nd Cotton 3 1st Hubam, Sudan 2nd Cotton 4 1st Oats-Hubam, Sudan 2nd Hubam, Sudan 3rd Cotton 5 1st Dallisgrass-White clover 2nd Dallisgrass-White clover 3rd ~ Cotton 6 1st Dallisgrass-White clover 2nd Dallisgrass-White clover 3rd Dallisgrass-White clover 4th Cotton 5th Cotton 7 1 st Fescueg rass 2nd Fescuegrass 3rd Fescuegrass 4th Cotton 5th Cotton 8. Continuous corn 9 1st Dallisgrass-White clover 2nd Dallisgrass-White clover 3rd Dallisgrass-White clover 4th Corn 5th Corn the major test. The test included two cropping sy tems, one of continuous cotton and the other a 3-ye cropping system of 2 years of Dallisgrass and Whi clover and 1 year of cotton. The general manag ment of this test was the same as in the major tes All of the forage crops produced in both tes were cut and baled for hay; none was used as gre manure crops. Fertilizer Treatments The fertilizer treatments used in this test we based on previously conducted experiments at Angl ton station (10) . In the main test each plot receiv an average of 3O pounds of available phosphor (P205) per acre per year. ivhere a legume appear in the cropping system, all of the phosphorus w applied at the beginning of the sequence when t legume was planted. Two levels of nitrogen we used in the main test. One-half of each plot receiv 60 pounds of nitrogen per acre per year and the oth half of the plot received no nitrogen. The supplemental fertilizer test included thr rates of nitrogen, 0, 45 and 90 pounds per acre u year, and two rates of available phosphorus (P205 0 and 30 pounds per acre per year. All of the ph phorus was applied to the legume at the beginni of the cropping sequence. Two extra treatments we added to each replication of the test so that potassiu (K20) could be tested at two levels, 90-30-30 '2' pounds of nitrogen, 30 pounds phosphorus as P2 ' and 30 pounds of potassium as K20) and 90-30- pounds per acre per year. ' Crops The selection of a cropping system should v based on the individual farmers needs. All t forage crops used in this study fit in well with G Coast Prairie farming and ranching enterprises. ats, Avena sativa, are the most popular small p‘ crop produced for forage on the Gulf Coast 7e. They are winter annual grasses which pro- _ l-forage of high quality from December to May, on when green forage is limited. Good stands ‘easy to obtain with little seedbed preparation. btain high yields, however, a well-drained and nably fertile soil is required. They produce rous small fibrous roots which penetrate the several feet. ats are used for grazing, hay, silage and as a _ g crop. They are an ideal crop when grown i e stands or as a companion crop with Hubam A_ The varieties, Mustang, Alamo and Goliad, Q been the most consistent in performance in this (7) . ats were recommended over all other temporary ‘A r pasture grasses until 1956 when they lost their i larity because of Helminthosporium blight and plant diseases such as smut, crown rust and rust (l) which seriously affect forage yields. oats will be planted in the area until new blight jdisease-resistant varieties are developed. _i RYEGRASS I ulf ryegrass, Lolium multiflorum, is a ryegrass released in 1958 by the Texas Agricultural riment Station and the Agricultural Research 'ce, USDA. 7n annual winter pasture grass on the Gulf 4 Prairie. Most of the acreage which has pre- ly been planted in oats has been replaced by _ ryegrass. Under normal conditions it can be as early as September 15 and will provide 'ng from November to June. Good stands can btained with little seedbed preparation. It grows on wet land, but forage yields are low if drainage or. It produces a very small, fibrous, shallow A system. ulf ryegrass is used for grazing, hay and silage. superior to the already popular Italian ryegrass f use it is more disease resistant, produces forage } a longer period of time, produces a higher yield Wed and reseeds itself (ll). _ ANGRASS udangrass, Sorghum vulgare sudanense, is one of ’ most valuable summer annual temporary pasture g es grown on the Gulf Coast Prairie. It can be i» ted as late as ]uneifll‘,~ makes rapid growth and is 7 th tolerant. Good stands and high yields have - obtained by drilling in 20-inch rows with a pas- A dream planter following oats, ryegrass and Hu- i; clover without any additional seedbed prepara- g Sudangrass is a fibrous-rooted plant which s in clumps. It produces good yields on soils It is becoming the most popular ' ranging from light sands to heavy clays. Highest yields are obtained from soils high in organic matter and fertility. It responds readily to nitrogen fertilizer. Sudangrass is used for grazing, hay and silage. It produces an abundance of leaves and sweet juicy stems that are readily eaten by livestock. The vari- eties most commonly grown in the area are Sudex and Sweet Sudangrass. Sudex is more palatable, pro- duces a nonshattering seed and is more disease re- sistant than most other Sudangrass varieties. DALLISGRASS Dallisgrass, Paspalum dilatatum, is one of the most desirable perennial warm-season‘ grasses pro- duced on the Gulf Coast Prairie. It grows in clumps and produces most of its leaves near the base of the plant. The plants normally grow 2 to 4 feet tall and produce forage of excellent quality. One of its most favorable characteristics is its deep, strong root system. Dallisgrass grows well on soils ranging from clays to sandy loams. It is very well adapted to Lake Charles clay which is found so extensively on the Gulf Coast Prairie. It requires a medium to high fertility level for good forage production (6). Dallisgrass is one of the first warm-season grasses to begin growth in the spring and one of the last to cease growing in the fall. In some years it remains green throughout the winter. A low of 26° F. on October 6, 1959, at the Angleton station, had no effect on Dallisgrass, while all other warm-season grasses showed severe damage. Its characteristic of growing in clumps makes it an ideal companion crop to be grown with Bermuda- grass and White clover. The mixture of Dallisgrass and Louisiana S-l White clover is very desirable. The forage produced by Dallisgrass is primarily used for grazing. It produces hay of high quality, but is not recommended as a hay crop because its leaves are produced near the soil surface and many of them cannot be harvested. The main disadvantages of Dallisgrass are the difficulty encountered in establishing a good stand, which is a result of poor seed quality and the low forage yields which are to be expected the first year after planting. FESCUEGRASS Ky 31 fescuegrass, Festuca arundinacea, is the best perennial cool-season grass grown on the Gulf Coast Prairie. It provides forage from late fall until early summer. Fescue roots are numerous and coarse and normally penetrate several feet through dense sub- soils. Stands are easy to establish and high yields can be expected the first year if it is planted on a fertile. moist soil and proper management practices 7 be disked to break up the larger clods and harrowed to level the seedbed. Levelling the seedbed is essential on the Gulf Coast Prairie to obtain the best possible surface drainage. If the seedbed is not level, poor stands will result from excessive moisture in the low spots in the field. If the seedbed is loose, it should be rolled before planting. SEEDING—OI1 the Gulf Coast Prairie the best time to plant grasses, legumes and small grains for grazing is between October 15 and December 1. Plantings made earlier will suffer from attacks of diseases, and the young seedlings from later plantings may be killed by frost. The best stands of Hubam, Louisiana S-l White clover and Dallisgrass were obtained when the seed were broadcast on the surface of a well-prepared seedbed and rolled with a corrugated roller or culti- packer. Oats and fescue were drilled in 10-inch rows before seeding the small seeded grasses and legumes. The legume seed were inoculated with the proper strain of bacteria. Sudangrass was planted in 20-inch rows about May l. FERTILIZERs-Since phosphorus does not move freely in the soil profile, it was broadcast on the surface and disked into the soil or was drilled into the soil in l0-inch bands before planting (8) . Thirty pounds of phosphorus (P205) per acre per year were applied at the time of planting the forage crops. All of the phosphorus to be applied to the cropping system was applied to the forage crops. Thus, the l, 2, 3 and 5-year systems would receive the equivalent of 30, 60, 90 and 150 pounds of phosphorus (P205) per acre when the forage crops were established. Each plot was split. One-half received the equiva- lent of 60 pounds of nitrogen fertilizer per acre per year, and the other half received no nitrogen fertilizer. The nitrogen fertilizer was broadcast annually on the various cropping systems in the following manner: Oats, Sudangrass The 60 pounds of nitrogen were divided equally between the oats and the Sudangrass, 30 pounds ap- plied in the fall at the time of planting the oats and 30 pounds applied in the spring at the time of plant- ing the Sudangrass. Hubam, Sudangrass The 60 pounds of nitrogen were applied to the Sudangrass and none to the Hubam clover. Oats-Hubam, Sudangrass; Hubam, Sudan The 60 pounds of nitrogen were divided equally between the oats-Hubam and Sudangrass the first year. When Sudangrass followed Hubam the second year, Sudangrass received all the nitrogen. l0 Dallisgrass-White Clover In those cropping systems containing Dallisgra and White clover, 15 pounds of nitrogen per ac were applied in the fall to enhance the establishme < of Dallisgrass. The remaining 45 pounds were a_ plied in the spring at the time White clover r. into its period of minimum production and at t ‘ time Dallisgrass is beginning its period of maximu production. Ky 2’! Fescuegrass Fescuegrass received 30 pounds of nitrogerf pe acre at planting time or at the time it began i growth in the fall. The remaining 30 pounds wer distributed as growth warranted. CRoP UTILIZATIQN-"Fhe forage crops in the variou cropping systems were selected in order to furnis year-round grazing as near as possible. Because o the design of the experiment, it was impossible t graze the various forage crops, so the forage w removed as hay. ‘ ROW CROPS LAND PREPARAT1oN-—Cotton and corn received th same seedbed preparation. Land going out of fora production and into row crops was disked in the as close to October as possible; around December th land was bedded and in early spring was row diske If land was used for continuous cotton and corn, row crops had followed row crops in the sequenc the row crops were shredded as soon after harv as possible. The land was then bedded and rebedd in December when possible and was disked light before planting. Early preparation of the seedb is important from the standpoint of insuring enou soil moisture for germination and early seedi 1 growth. SEEmNc-Deltapine 15 cotton was planted April 1 0 as soon after that time as weather conditions we favorable. The seed were planted l to 2 inches de on top of the beds, at a rate of 20 to 30 pounds c seed per acre. The final stand was thinned to thr to four plants per foot of row. Corn on the Gulf Coast Prairie should be plant as close to March 15 as possible. Texas Hybrid “L is the corn hybrid recommended for the area. Und - dryland conditions 18-inch spacing between plan in 40-inch rows, or 8,500 to 9,000 plants per acre, h given the highest yields at the Angleton statio Under irrigation, spacing of 12 to 9 inches in 40-in rows, or 12,000 to 16,000 plants per acre, is reco mended for highest yields. FERT1L1zERs-The continuous cotton and corn receiv - the equivalent of 30 pounds of available phospho 1 (P205) per acre at the time of planting. All é the row crops received two levels of nitrogen f tensively throughout the area. Texas hybrids 3nd 28 are the most productive yellow hybrids, exas 17W and Asgrow 101W are the most white hybrids (3). Cropping Systems f nine cropping systems tested during this study ‘7 of cotton and corn, grown continuously and with the forage crops best adapted to the Gulf ‘fPrairie. A i; UOUS COTTON tinuous cotton was planted on the same land ter year. This is the most common practice p’; the area. It is one of the main reasons * Gulf Coast Prairie’s low average cotton yields. ZSUDANGRASS; COTTON l this 2-year cropping system with the first year i» to oats and Sudangrass followed by cotton ,ond year, the oats were planted in the fall inter forage and the Sudangrass was planted g spring for summer forage. These crops were to determine their value as a temporary pas- op and the value of a cropping system con- only grasses as a soil improvement practice. _ , SUDANGRASS; COTTON u is also a 2-year cropping system. The first {Hubam was planted in the fall and Sudangrass spring. Cotton was planted the second year. {cropping system was tested to determine the of Hubam clover as a temporary pasture crop o determine the value of having a legume in “ar cropping system as compared with a 2-year a containing only grasses. HUBAM, SUDANGRASS; I , SUDANGRASS; COTTON 1 this 3-year cropping system, oats and Hubam planted in the fall of the first year followed jylate-spring planting of Sudangrass. In the sec- i ear, Hubam was fall planted, followed by Sudan- 'in the spring. Cotton was planted in the third _i is system was tested to evaluate the effect of rs of temporary pasture containing both grasses “a legume as a soil improvement practice. ,|senAss-wn|ns CLOVER, 2 YEARS; ON, 1 YEAR - i 3-year cropping system of 2 years of Dallisgrass gWhite clover followed by one year of cotton was I to determine the value of a permanent type g re mixture of a grass and a legume upon soil ovement and to determine the merits of a per- dent type pasture versus temporary pasture crops. DALLISGRASS-WHITE CLOVER, 3 YEARS; COTTON, 2 YEARS A 5-year cropping system of 3 years of a Dallis- grass and White clover pasture mixture followed by 2 years of cotton was tested. This test was used to determine the merits of a long-time cropping system containing a permanent type pasture mixture of a grass and a legume, as compared with a short-time system having temporary pasture crops. The test was also used to determine the effect of having cotton in the system more than l year. FESCUEGRASS, 3 YEARS; COTTON, 2 YEARS A 5-year cropping system of 3 years of fescuegrass followed by 2 years of cotton was tested to determine the merits of a long-time cropping system containing only grasses as compared with a system having a grass and a legume. It was also tested to determine the merits of fescuegrass as a permanent type pasture grass for winter forage production and as a soil im- provement crop. CONTINUOUS CORN Corn was planted year after year on the same land, which is the cropping system most commonly used by corn farmers in the area. This system was used to determine the effects of continuously planted corn as compared with corn rotated with a grass and a legume. It also helped in determining the effects of continuous cotton versus continuous corn. DALLISGRASS-WHITE CLOVER, 3 YEARS; CORN, 2 YEARS A 5-year cropping system of 3 years of Dallisgrass and “lhite clover and 2 years of corn was tested to determine the value of these forage crops as soil improvement crops when rotated with corn. This system also was used to determine the influence of corn and cotton on the yields of Dallisgrass and l/Vhite clover. Management Practices FORAGE CROPS LAND PREPARATION-All of the forage crops tested, ex- . cept Sudangrass, received the same seedbed prepara- tion. Sudangrass was planted in oats and Hubam stubble after they had been harvested for hay. Seedbed preparation is the most important single factor in the establishment of small seeded grasses and legumes. Good seedbeds result in good stands, a good balance between grass and legume plants, good weed control and early grazing. Well-prepared seedbeds will help in the control of insects and dis- eases. When small seeded grasses and legumes are to be planted following row crops, the crop residue should be shredded as soon after harvest as possible. The residue should be plowed under, and the land should 9 be disked to break up the larger clods and harrowed to level the seedbed. Levelling the seedbed is essential on the Gulf Coast Prairie to obtain the best possible surface drainage. If the seedbed is not level, poor stands will result from excessive moisture in the low spots in the field. If the seedbed is loose, it should be rolled before planting. SEEDING-On the Gulf Coast Prairie the best time to plant grasses, legumes and small grains for grazing is between October 15 and December l. Plantings made earlier will suffer from attacks of diseases, and the young seedlings from later plantings may be killed by frost. The best stands of Hubam, Louisiana S-l White clover and Dallisgrass were obtained when the seed were broadcast on the surface of a well-prepared seedbed and rolled with a corrugated roller or culti- packer. Oats and fescue were drilled in 10-inch rows before seeding the small seeded grasses and legumes. The legume seed were inoculated with the proper strain of bacteria. Sudangrass was planted in 20-inch rows about May l. FERTILIZERs-Since phosphorus does not move freely in the soil profile, it was broadcast on the surface and disked into the soil or was drilled into the soil in 10-inch bands before planting (8) . Thirty pounds of phosphorus (P205) per acre per year were applied at the time of planting the forage crops. All of the phosphorus to be applied to the cropping system was applied to the forage crops. Thus, the 1, 2, 3 and 5-year systems would receive the equivalent of 30, 60, 90 and 150 pounds of phosphorus (P205) per acre when the forage crops were established. Each plot was split. One-half received the equiva- lent of 6O pounds of nitrogen fertilizer per acre per year, and the other half received no nitrogen fertilizer. The nitrogen fertilizer was broadcast annually on the various cropping systems in the following manner: Oats, Sudangrass The 6O pounds of nitrogen were divided equally between the oats and the Sudangrass, 30 pounds ap- plied in the fall at the time of planting the oats and 30 pounds applied in the spring at the time of plant- ing the Sudangrass. Hubam, Sudangrass The 60 pounds of nitrogen were applied to the Sudangrass and none to the Hubam clover. Oats-Hubam, Sudangrass; Hubam, Sudan The 60 pounds of nitrogen were divided equally between the oats-Hubam and Sudangrass the first year. When Sudangrass followed Hubam the second year, Sudangrass received all the nitrogen. 10 Dallisgrass-White Clover In those cropping systems containing Dallisgr and “Thite clover, l5 pounds of nitrogen per -, were applied in the fall to enhance the establishm of Dallisgrass. The remaining 45 pounds were plied in the spring at the time White clover v‘ into its period of minimum production and at time Dallisgrass is beginningYitk period of maxim production. Ky 31 F escuegrass Fescuegrass received 30 pounds of nitrogen acre at planting time or at the time it began. growth in the fall. The remaining 30 pounds w distributed as growth warranted. e CRoP urlLrzArroN-"The forage crops in the vari cropping systems were selected in order to fur year-round grazing as near as possible. Because the design of the experiment, it was impossible graze the various forage crops, so the forage l.‘ removed as hay. ROW CROPS LAND PREPARATIQN-Cotton and corn received f same seedbed preparation. Land going out of f0 i production and into row crops was disked in the as close to October as possible; around December i‘ land was bedded and in early spring was row dis If land was used for continuous cotton and corn, row crops had followed row crops in the seque the row crops were shredded as soon after ha as possible. The land was thenbedded and rebed in December when possible and was disked li before planting. Early preparation of the seed is important from the standpoint of insuring eno soil moisture for germination and early see growth. SEEmNc-Deltapine 15 cotton was planted April _ as soon after that time as weather conditions favorable. The seed were planted 1 to 2 inches u? on top of the beds, at a rate of 20 to 30 pound seed per acre. The final stand was thinned to r to four plants per foot of row. Corn on the Gulf Coast Prairie should be pla as close to March 15 as possible. Texas Hybrid is the corn hybrid recommended for the area. U dryland conditions 18-inch spacing between p in 40-inch rows, or 8,500 to 9,000 plants per acre, given the highest yields at’ the Angleton sta Under irrigation, spacing of 12 to 9 inches in 40- rows, or 12,000 to 16,000 plants per acre, is re mended for highest yields. i FERTILIZERS——Tl1€ continuous cotton and corn rec the equivalent of 30 pounds of available phosp (P205) per acre at the time of planting. ‘i the row crops received two levels of nitrogeni One-half of the plot received 60 pounds of f,- per acre and the other half received no i’. The ‘nitrogen was applied at planting. tilizers were applied in bands 4 to 5 inches side and at about the same depth at which _~ were planted. AT1oN—Good cultivating practices were carried 'ng the test. Standard planting equipment at the timeof planting. A rotary hoe ent was used for the first cultivation after ts were up. The remaining cultivations were a minimum and were used only to control if‘ vAll cultivations were shallow in order to con- oisture and to prevent as much root damage i; e should be no cultivation for any reason to control weeds which compete with row or nutrients and soil moisture. A large num- 1' farmers reduce their cotton and corn yields _’~ cultivation, which dries out the Lake Charles '1 to the depth at which it is cultivated and or injures many roots, thus weakening the Yand corn plants. g‘ coNTRoL-During the experiment, insecticide measures recommended by Texas Agricultural u Extension Service Leaflet 218, “Texas Guide for Con- trolling Cotton Insects,” were carried out. No in- secticides were used for controlling corn insects. EFFECTS OF NITROGEN FERTILIZER ON FORAGE YIELDS All of the forage crops receiving nitrogen fer- tilizer produced higher yields than those receiving no nitrogen, Table 3. Those cropping systems con- taining a legume produced the highest yields both with and without nitrogen fertilizer. The three cropping systems producing the highest forage yields with 60 pounds of nitrogen per- acre per year were: (1) Hubam, Sudan—l0,880 pounds per acre; (2) oats- Hubam, Sudan—lO,l00 pounds per acre; (3) Dallis- grass-White clover-9960 pounds per acre. Without nitrogen the yields were: (1) Hubam,Sudan—8,350 pounds per acre; (2) oats-Hubam, Sudan—-8,840 pounds per acre; and (3) Dallisgrass-lVhite clover- 8,530 pounds per acre. The cropping systems which showed the greatest response to nitrogen fertilizer were those which did not contain a legume. Fescuegrass produced greatest yield increases due to nitrogen. Based on 3-year averages and compared with nonfertilized fescuegrass, THE INFLUENCE OF CROPPING SYSTEMS AND NITROGEN FERTILIZER ON FORAGE YIELDS Nitrogen per acre, pounds Average 1956 1957 1958‘ 1956-58 Crop 60 None 60 None 90 15 60 None Pounds of air-dry forage per acre Continuous cotton Oats, 3950 1520 1780 1740 5150 2480 3630 1910 Sudan 4670 4300 2 2 3920 3370 4290 3830 Cotton Hubam, 5530 4630 3060 3240 5530 5900 5710 4590 ' Sudan 4830 2770 2 “ s51 o 4750 5170 3760 Cotton ~ Oats-Hubam, 5350 3690 1400 2700 8440 5070 5060 3820 Sudan 5200 4700 2 2 4880 4630 5040 4660 Hubam, 5490 5640 2620 2870 4050 4690 4050 4400 Sudan 6170 2330 2 2 5100 4080 5640 3210 Cotton Dallisgrass-White clover 4190 2480 3120 3020 6440 5860 4580 3790 DaIlisgrass-White clover 6850 5660 8640 6660 7210 9730 7570 7350 Cotton DalIisgrass-White clover 4170 2470 2850 2980 6580 6340 4530 3930 Dallisgrass-White clover 7100 6890 9760 8260 8410 8380 8420 7840 Dallisgrass-White clover 5860 5260 12810 10680 1 1210 9660 9960 8530 Cotton Cotton Fescuegrass 3460 ‘I610 14990 3200 6030 2530 8160 2450 Fescuegrass 5500 3850 12000 3280 9950 5230 9150 4120 Fescuegrass 2620 1880 5700 5170 10870 5770 6400 4270 Cotton Cotton 3Q 1., Continuous com DaIIisgrass-Whife clover 2740 2290 2740 2840 5930 6030 3800 3720 DaIIisgrass-White clover 5230 6010 5250 4830 8720 7870 6400 6240 Dallisg rass-White clover 5140 5250 9740 8600 9680 10100 8190 7680 Corn Corn i the nitrogen fertilizer treatments were increased from 60 pounds per acre to 90 pounds, and the no-nitrogen treatment to 15 pounds per to obtain a stand of Sudangrass in 1957 due to lack of moisture. 11 nitrogen increased the yield of first-year stands 233 percent; second-year stands, 122 percent; and third- year stands, 50 percent. Nitrogen applied t0 oats at the rate of 60 pounds per acre gave a 90 percent increase in yield over nonfertilized oats. lt was difficult to maintain a good stand of grass in the cropping systems receiving no nitrogen fer- tilizer. When nitrogen was applied, stands were easily maintained. FORAGE CROPS RECOMMENDED FOR CROPPING SYSTEMS CONTAINING COTTON AND CORN The high forage yields obtained from all the cropping systems more than offset the cost of estab- lishing the forage crops, and a good income was obtained from the land when it was in forage pro- duction. The cropping system with the lowest yield produced a 3-year average of 2 tons of air-dry forage per acre per year. The system with the highest yield produced an average of 5 tons of air-dry forage per acre per year. These yields would have been higher, in all probability, if normal rainfall had occurred in 1956. The rainfall for 1956 was 17.4 inches below the 45-year average at the Angleton station, Table 1. Oats, Sudangrass; Cotton A 2-year system of first-year oats and Sudangrass and second-year cotton produced lower forage yields than any other system tested, Table 3. It also showed little effect upon soil improvement. Oats planted alone required nitrogen fertilizer to obtain high yields. Nonfertilized oats produced an average of 1,910 pounds of air-dry forage per acre. When 60 pounds of nitrogen were applied, yields were in- creased 90 percent. Pure stands of oats provide grazing for a short time when it is most needed on the Gulf Coast Prairie. Oats were recommended over all other temporary winter pasture grasses until 1956. They have now lost their popularity due to Helminthosporium blight and other plant diseases found on the humid coastal prairie. These diseases were the cause of the low forage yields produced by this cropping system. Until new disease-resistant varieties are developed, oats are not recommended for the area. i Gulf ryegrass, a variety released in 1958, is now recommended instead of oats. Gulf ryegrass, as com- pared with oats, is more disease resistant, produces higher forage yields over a longer time and is able to reseed itself. Gulf ryegrass replaced oats in this study in 1960. During that year Gulf ryegrass, receiving 15 and 90 pounds of nitrogen per acre, produced 4,290 and 7,120 pounds of air-dry forage per acre, respectively. It was easy to obtain stands of Sudangrass following oats and Gulf ryegrass. 12 Hubam, Sudangrass; Cotton A 2-year system of first-year Hubam and Sudan grass and second-year cotton produced a yearly tota of 8,350 pounds of air-dry forage per acre. This a one of the higher forage yields obtained from th cropping systems receiving no nitrogen fertilize Hubam clover produces themajority of its forag in the late spring when theisiimmer grasses are i _ production and normally the forage is not neede It is believed that Sudangrass in the systems co taining Hubam reduced forage yields. In prepzfri the land for planting Sudangrass, it was necenssa to remove the Hubam clover at the time it was b ginning to make its maximum production. It wy difficult to obtain a good stand of Sudangrass follo ing Hubam because of the lack of moisture. 2 Israel sweetclover, (Melilotus alba var. arm Coe) is a new variety of annual sweetclover releas in 1958. This clover has good possibilities of repla ing Hubam on the Gulf Coast Prairie. It could f, in well in the cropping systems. Because of its la maturity, Sudangrass could be dropped from the s tern, and high forage yields over a long period cou still be obtained. Oats-Hubam, Sudangrass; Hubam, Sudqngra Cotton a High forage yields were obtained from a 3-ye system of first-year oats-Hubam, Sudangrass; secon year Hubam, Sudangrass and third-year cotton. T i system fits in well in the area and is recommend over the two systems containing oats or Hubam. T system has several advantages other than produci higher forage yields. When oats and Hubam w planted together, they provided grazing over a lon period than when the two crops were planted s arately. It was observed that when this system l in cotton there were not so many weeds, the .| was easier to work and better stands of cotton w obtained. u The disadvantage of this 3-year system, which a applied to the systems of pure stands of oats a Hubam followed by Sudangrass, is that it requi two planting operations a year. The fall. planti in October of oats and Hubam, and spring plant'_ of Sudangrass occurs when the farmer is either vesting or planting his row crops. Another dis vantage is that livestock must be kept off the l until the crops are large enough to graze. a Field observations in 1957-59 indicate that in the plots planted to cropping systems contain Hubam clover, the “workability" of the soil was proved over all other systems and better stands cotton were obtained. It also appeared that a heavy rains cropping systems containing Hub clover showed better moisture penetration. i . Dallisgrass and La. S-‘l White clover is the most ended pasture mixture for the Gulf Coast Prairie. This in March i957 shows a good balance of grass and llt is necessary to keep down the possibility of bloat , llisgrass-White Clover, 2 Years; Cotton, l Year grass and White clover have many advan- ' a grass and clover pasture combination. Together, these two furnish almost year-round Figures 2 and 3. One of the main advan- having Dallisgrass and White clover in a system is that only one planting operation ed for the time the system is in forage _'0n. l are some disadvantages of having these @217 opsin a cropping system. A very good seed- t be obtained to insure a good stand of - s, while a stand of White clover is easy 'n even on a poor seedbed. A good stand Dallisgrass and White clover is necessary down the possibility of bloat in cattle which 5;» cur on a pure stand of White clover. An- isadvantage is that 2 to 3 years are necessary in high forage yields of Dallisgrass. The 3-year taken from Table 3 shows an 86-percent in- iln forage yields in second-year yields over first- gelds, and an 18-percent increase in third-year iyields over the second-year yields. Still another ntage of a Dallisgrass and White clover pas- the difficulty encountered in obtaining a good l- for cash crops of cotton and corn. Even lyese disadvantages, cropping systems containing i} ass and White clover are recommended over f] er systems. Dallisgrass-White Clover, 3 Years; Cotton or Corn, 2 Years the nine cropping systems used in this test, year system containing 3 years of Dallisgrass iuisiana S-l White clover followed by 2 years ton or corn is the one most recommended over Figure 3. A third-year stand of Dallisgrass and White clover produced an average of 12,810 pounds of air-dry forage per acre in 1957. This picture taken in August shows the growth habits and seeding characteristics of Dallisgrass. La. S-'l White clover (bottom of the picture) is still making active growth. the other systems. It conforms well with the live- stock program throughout the area, and Dallisgrass and White clover pastures are the most productive pastures in the area. They also increase the yields of the chief cash crops, cotton, corn and rice. Cropping systems containing 3 years of Dallisgrass and White clover are recommended over 2-year sys- tems because of the increased forage yields obtained from third-year systems over second-year systems, and the high cost of establishment of a good Dallisgrass and White clover pasture. Fescuegrass, 3 Years; Cotton, 2 Years This 5-year system has several advantages on the Gulf Coast Prairie. Fescuegrass provides forage over a long growing season from late fall until early sum- mer. It requires only one planting operation during its duration in the system and with the addition of nitrogen fertilizer, high forage yields can be expected the first year it is in the system. Fescuegrass has several disadvantages which have made it unpopular at the Angleton station. It is difficult to maintain a good stand of fescuegrass, and it is necessary to keep stock off the land during the summer months. The stock should be taken off early enough to allow the fescuegrass to produce seed. Low l3 FOLLOWING TWO YEARS OF COTTON FOLLOWING TWO YEARS OF CORN POUNDS OFAIR DRY FORAGE PER ACRE (THOUSANDS) 3rd ' Ist 2nd YEAR m DALLISGRASS-WHITE CLOVER PASTURE The influence of cotton and corn on the yields of Figure 4. Dallisgrass-White clover. yields are to be expected without the use of nitrogen fertilizer. First, second and third-year stands of fescuegrass produced 8,160, 9,150 and 6,400 pounds of air-dry forage per acre, respectively, with applica- tions of 60 pounds of nitrogen per acre per year. Where no nitrogen was applied, 2,450, 4,120 and 4,270 pounds of forage was produced in the first, second and third years, respectively, Table 3. Even when high yields are obtained by using nitrogen fer- tilizer, production was poor when considered on an annual basis. In preparing the land for cotton, the plots coming out of fescuegrass were harder to work that the plots in any other system, and the poorest stands of cotton were obtained on these plots. The growing season in 1957 was very favorable for fescuegrass. The plots fertilized with 60 pounds of nitrogen per acre produced average yields for firs ‘ second and third-year stands of 14,900, 12,000 an 5,700 pounds of air-dry forage per acre, respectivel The nonfertilized plots produced an average of onl 3,200, 3,280 and 5,170 pounds of air-dry forage p acre in the first, second and third-year stan respectively. A Cropping systems containing ‘pure stands of fescu grass are not recommended for the Gulf Coast Prair without the use of high rates of nitrogen fertilize (9. INFLUENCE OF COTTON AND CORN * ON THE YIELDS OF DALLlSGRASS-WHITE CLOVER The influence of cropping systems containing c ton and corn on the yields of Dallisgrass and Whi clover is shown in Figure 4. These two forage cro following cotton produced higher yields than wh following corn. Nitrogen fertilizer was more signi cant in increasing forage yields of Dallisgrass a White clover following cotton than when these fora crops followed corn. INFLUENCE OF CROPPING SYSTEMS ON COTTON YIELDS Cotton Yields, 1953-57 The yields of cotton obtained from various cro ping systems without nitrogen and with 60 poun of nitrogen per acre per year for 1953-57 are giv in Table 4. Weather conditions were unfavorable for hi cotton yields during the 5 years in which the t was conducted. Yields were extremely low in I9 and 1955 because of the lack of moisture necess to germinate seed to a good stand, and insufficie TABLE 4. THE INFLUENCE OF CROPPING SYSTEMS AND NITROGEN FERTILIZER ON COTTON YIELDS, 1953-57 Pounds of seed cotton per acre Year in No nitrogen 60 pounds of nitrogen per acre system Cropping system 1953 1954 1955 1956 1957 1953 1954 1955 1956 19 Continuous Continuous cotton 380 1480 360 970 1280 340 1660 620 1010 1 Ist Oats, Sudan 1st Cotton 540 1470 430 1010 1170 410 1560 430 1070 1 1st Hubam, Sudan . y 1 st Cotton 650 1580 460 1220 1200 550 1620 310 1200 1 Ist Oats-Hubam, Sudan 2nd Hubam, Sudan ' 1 st Cotton 470 1470 350 1170 1310 500 1660 370 1190 1 A 1st Dallisgrass-White clover 2nd Dallisgrass-White clover 1 st Cotton 410 1360 710 1130 1130 640 1850 600 1250 I 1st Dallisgrass-White clover 2nd Dallisgrass-White clover 3rd Dallisgrass-White clover 1st Cotton 380 1420 430 1210 I250 500 1660 350 1230 I v 2nd Cotton 530 1360 390 1220 1200 580 1830 580 1230 I Ist Fescuegrass s 2nd Fescuegrass 3rd Fescueg rass 1 st Cotton 400 I290 360 820 860 480 1650 510 840 1's 2nd Cotton 570 1420 340 970 1 180 700 1800 590 1 100 Continuous Cotton Outs, Sudon Cotton Hubom , Sudon Cotton Outs-Hubom , Sudon Cotton Dollisgross,Wh.C|. Cotton Dollisgross ,Wh. CI. Cotton Cotton H37. o 35% +16% ¢35'/¢ Fescuegrass Cotton Cotton +28% +27% 7O 6O 9O IOO ll0 I20 I30 I40 YIELDS IN PERCENT 0F CHECK 50 60 figure 5. The effect of 60 pounds of nitrogen per acre on of cotton in various cropping systems, 1954. during the growing season prevented the cot- plants from maturing a normal crop of bolls, 1. Under normal conditions, the Angleton produces 11/2 bales of cotton per acre without tal irrigation. 1953 the cotton was planted on land that had in row crops of cotton or corn for 50 years. The yields showed no significant difference due rotation or nitrogen fertilizer. 1954 none of the cotton had been preceded by improving crop for more than 1 year. There no significant difference in cotton yields due rotation. The rainfall during the growing was favorable for the use of nitrogen fertilizer. tions of 6O pounds of nitrogen per acre pro- Cropping System Continuous Cotton Dots, Sudon Cotton Hubom , Sudon Cotton Outs, Hubom, Sudon Hubom, Sudan Cotton Dollisgross,Wh.Cl. Cotton Dollisgrass , Wh. Cl. Cotton Dollisgross, Wh. CI. Cotton Fescuegross Cotton Fescuegross Cotton ¢2l°k ¢l8% H770 +24% 025% +22% 26$ ¢22% 46% —l77o 0% +995 75 80 85 9O 95 I00 I05 IIO II5 I20 I25 I50 6. The effect of cropping systems on the yields of receiving no nitrogen and 60 pounds of nitrogen per acre , I956. Figure 7. Continuous cotton receiving yearly fertilizer treat- ments of 0-30-0 produced only 970 pounds of seed cotton per acre in ‘I956. Note the short height of plants (‘l8 inches) and few number of blooms. duced from 2 to 36-percent increases in cotton yields in all of the cropping systems tested, Figure 5. In 1955, as in 1953, cotton yields were extremely low due to lack of moisture. All of the cropping systems, except the 5-year systems, had gone through a complete cycle. Crop rotation and nitrogen fer- tilizer caused no significant increase in yields. In 1956 it became apparent that cotton yields were being increased by rotation. Four of the seven crop- ping systems tested in this experiment produced a highly significant increase in yields of rotated cotton over continuous cotton, Figure 6. The cropping systems containing a legume pro- duced the highest percentage increase in yields. Non- fertilized cotton following 1 year of Hubam, Sudan Figure 8. Cotton rotated w-ith Dallisgrass and White clover and receiving a yearly fertilizer treatment of O-30-O produced 1,220 pounds of seed cotton per acre in I956. This gave a 26 percent increase in yields over continuous cotton receiving the same fer- tilizer treatments. Note height (26 inches) and increase in number of blooms even during drouth period as shown by cracking of soil between cotton rows. 15 Figure 9. In 1957 cotton rotated with Dallisgrass and White clover and receiving a yearly fertilizer treatment of 60-30-O per acre produced only 'l,23O pounds of seed cotton per acre. The 6O pounds of nitrogen only increased cotton yields ‘IO pounds per acre. Note height of plant (36 inches) and large number of blooms as com- pared with Figures 7 and 8. If normal rainfall had occurred, probably there would have been a high increase in yields clue to nitrogen fertilizer as well as crop rotation. and second-year cotton following 2 years of Dallis- grass and White clover produced 26-percent increases in yields over continuous nonfertilized cotto-n, Figures 7 and 8. In the same systems cotton with 6O pounds of nitrogen produced 19 and 22-percent increases in yields, respectively. Continuous cotton was better than cropping sys- tems that did not contain a legume. Cotton follow- Yrs.in Syst. Cropping System 5yrs. Continuous Cotton No N- so N. lst. Oots, Sudon - e v. 2nd. Cotton + w. lst. Hubom, Sudon 45% 2nd. Cotton so N. I +7 as lst. Oots, Hubom,Sudon 2nd. Hubom, Sudon 3rd. Cotton +2°lu +l9°/o -l2°/¢ 2nd. Dollisgross,Wh.,C|. l’ +970 3rd. Cotton 3rd. Dollisgross, Wh., Cl. - 2% 4 th. Cotton + 2% 5th. Cotton l ————j ' 6% 6O N. + l4°/o 3rd Fescuegross No N. 43% 4th. Cotton so N. | -1s% - ass 5th. Cotton so N J +15% 1 1 1 I 1 1 1 1 1 T5 8O BO 9O 95 IOO I05 IlO ll5 I20 I25 YIELOS IN PERCENT OF CHECK Figure 10. The effect of cropping systems on the yields of cotton receiving no nitrogen and 6O pounds of nitrogen per acre per year, 1957. l6 I Yrs.in Syst. Cropping System 5yrs. Continuous Cotton I st. Oots, Sudon g 2nd Cotton +6 lst. Hubom, Sudan 2nd. Cotton lst. Oots, Hubom, Sudon 2nd. Hubom, Sudon 3rd. Cotton +1 2yrs. Dollisgross,Wh. CI. QC 3rd . Cotton + _ 3yrs. Do|lisgross,Wh. Cl. I No N. 4th. Cotton 1 No N. g 5 th. Cotton so N. J + _ 3yrs. Fescuegross flfllflfiifiifiz}:§:§:§:§:§:§:§:§:§:§:§ + 4th. Cotton 6° N- _ 5th. Cotton so N. 1 l l l l l l ’ 75 8O 85 9O 95 IOO I05 HO ll5 *3 YIELOS IN PERCENT OF CHECK Figure l1. The effect of 6O pounds of nitrogen per ac the yield of cotton in various cropping systems, 1957. ing 1 year of oats, Sudan with and without nitr, produced 6 and Lit-percent increases in yields, spectively, over continuous cotton receiving the f. fertilizer treatments. First-year cotton followi years of fescuegrass with and without nitrogen tilizer produced 17 and 16-percent decreases in c: yields, respectively. i In the nonfertilized cotton, crop rotation w_ effective in increasing cotton yields as a fert' application of 60 pounds of nitrogen per acre, ‘A ure 9. ~ In 1957 all of the cropping systems had through one complete cycle. Cotton yields sh a continued significant increase in yields due to i rotation, Figure 10, and a highly significant at in yields due to nitrogen fertilizer, Figure ll. was no significant difference in yields, due to interaction of crop rotation and nitrogen ferti Figure l2. i NO NITROGEN y, Field observations during the years in whici test was conducted have shown that continuous fertilized cotton reached maturity 3 weeks e,‘ than rotated cotton and cotton receiving nit fertilizer. This was an advantage in 1957 for} fertilized continuous cotton. The continuous c bloomed and set bolls while the rotated fert cotton was still producing vegetative growth. weather turned dry, and the test area had ‘l trace of rain for 6 weeks. The Lake Charles dried and cracked deeply, and the late cotto_ unable to set a normal crop of bolls. f Cropping System l Continuous Cotton . 4% 0ots,Sudon Cotton sou. 1m i _ Hubam, Sudon ' Cotton sou. ] +sec 0ots,Hubom,Sudon s_ Hubom,Sudon Y-i Cotton sou. I "49- 5 .Dollisgross,wh. Cl. 5 Cotton so u. ' I t 5% ‘ Dollisgross,Wh. Cl. ‘ Cotton sou. ' 4% ‘i Cotton so M i +90; ‘ Fescuegross p 1 Cotton sou. 44% A Cotton so u. j +10% I i I 1 l l l I 75 BO B5 9O 95 IOO I05 IIO I15 I20 I25 YIELDS IN PEROENTOF CHECK ure l2. The effect of cropping systems and nitrogen on d of cotton, ‘I957. he use of 6O pounds of nitrogen per acre 0n , uous cotton caused a decrease in yields as red to the nonfertilized continuous cotton. p ntinuous nonfertilized cotton produced higher than cotton in six of the seven cropping sys- j tested in 1957. The effect of cropping systems “onfertilized cotton is presented in Figure 10. idecrease in yields ran from 2 percent for cotton ’ ing Dallisgrass and White clover to 33 percent otton following fescuegrass. The only increase felds obtained from nonfertilized cotton was in ppping system containing 2 years of Hubam The results obtained from nonfertilized cot- _,'n I957 were the opposite of those obtained in More emphasis should be placed on the 1956 than the 1957, as the weather conditions occur- =in 1957 were very unusual for the Gulf Coast 1e. EN he effects of cropping systems on cotton yields ving 6O pounds of nitrogen per acre for 1957 own in Figure l0. There was an increase in in six of the seven cropping systems tested. if highest increase in yields was obtained from ping systems containing a legume. p, tton in a 2-year cropping system of first-year m, Sudan and second-year cotton, and a 3-year of first-year oats-Hubam, Sudan; second-year m, Sudan and third-year cotton produced a 7 19-percent increase Vin yields, respectively, over h’ uous cotton. Tlieitwo systems which contained grass and Whitelclover (a 3-year system of 2 of Dallisgrass and White clover and 1 year n, and a 5-year system of 3 years of Dallisgrass- e clover followed by 2 years of cotton) produced Land l4-percent increases in yields, respectively. g n in a 2-year system of l year oats, Sudan and 1 year cotton made only a l-percent increase in yields. In a 5-year system of 3 years of fescuegrass and 2 years cotton, first-year cotton produced a 13-percent de- crease in yields and second-year cotton produced a 15-percent increase in yields. The effects of nitrogen fertilizer on the yields of cotton in 1957 are presented in Figure ll. The applications of 60 pounds of nitrogen per acre ap- plied at planting produced a highly significant in- crease in cotton yields in six of the eight cropping systems tested. The two systems in which nitrogen fertilizer did not produce an increase in yields were continuous cotton and first-year cotton following 3 years of Dallisgrass and White clover.‘ The system producing the highest increase in yields because of nitrogen was first and second-year cotton following 3 years of fescuegrass. This system showed an in- crease in yields of 24 and 20 percent, respectively. The increase in yields caused by nitrogen was very apparent in field observation. The cotton which had received nitrogen withstood drouth better than the nonfertilized cotton. Since the fertilized cotton main- tained a good color, did not shed its leaves and was able to resume growth and set cotton bolls, it made a late cotton crop. The cotton which did not receive fertilizer and the fertilized continuous cotton did not recover after the drouth. Effects of Nitrogen on Cotton Yields Nitrogen fertilizer applied at the rate of 60 pounds per acre per year increased the yields of cotton in all the cropping systems in 1954, 1956 and 1957, Figure 13. The greatest increase in yields due to nitrogen was in the 3-year system of 2 years of Dallisgrass- White clover and 1 year of cotton. This system produced a 22-percent increase in yields over cotton in the same system which did not receive nitrogen. Yrs.in Syst. Cropping System Continuous Cotton l ~4% lst. Oots , Sudon 2nd. Cotton J +1'/- lst. Hubom,Sudon 2nd Cotton 1 w. i st . Oots-Hubom,Sudon 2nd. Cotton l #87- 2yrs. Dollisgross,Wh. Cl. 3rd. Cotton +22%] 3yrs. Dallisgrass ,Wh.Cl. 4th. Cotton J um 5m. Cotton 1 new 3yrs. Fescuegross 4th. Cotton ] +20% 5th. Cotton ] .211. 1s ob as so 9's I00 ios lfO iis téo tés YIELDS IN PERCENT or CHECK Figure ‘l3. The effect of 6O pounds of nitrogen per acre per year on the average yields of cotton in various cropping systems, ‘I954, ‘I956 and 1957. I7 TABLE 5. AVERAGE YIELDS OF SEED COTTON PER ACRE AS INFLU- ENCED BY FERTILIZER AND CROP ROTATION, 1954-57 Averaqe yields of seed cotton per acre Fertilizer 1954 1955 1956 1957 1954-57 Confinuouscofion 0-0-0 I550 680 830 810 970 0-30-0 1360 840 930 800 980 45-0-0 1640 830 z 980 1070 1130 45-30-0 I900 600 1120 1040 1170 90-0-0 1740 670 940 1010 1090 90-30-0 1670 650 1000 1000 1080 90-30-30 1620 860 1000 980 I 120 90-30-60 1980 950 1390 1120 I360 Cotton in a 3-year cropping system of 2 years Dallisgrass-White clover; 1 year cotton 0-0-0 15901 1310 1090 690 1 170 0-30-0 1660 1610 1230 s20 1330 45-0-0 1760 1600 1250 990 1400 45-30-0 1760 1910 1210 1060 1490 90-0-0 1630 1080 1160 1000 1230 90-30-0 1740 1950 1290 1040 1510 90-30-30 1920 1660 1130 1100 1450 90-30-60 2150 1760 . 1210 1110 1560 lThe cotton in 1954 followed only 1 year of Dallisgrass-White clover. The smallest increase in yields caused by nitrogen was produced by continuous cotton and cotton in a 2-year system of Hubam, Sudan and cotton. These systems produced an increase of 4 percent over the same systems which did not receive nitrogen. Statistical analysis of the cotton yields shows that there was no significant difference in yields due to any of the treatments in 1953. In 1954 there was a highly significant difference in the increase of yields because of nitrogen fertilizer. In 1955 there was a significant difference because of the interaction of nitrogen and crop rotation. In 1956 the effect of cropping systems became apparent in increasing yields. In 1956 and 1957 there was a highly signifi- cant increase in yields because of the crop rotation and nitrogen fertilizer. Cropping Systems Recommended for Cotton Based on the information obtained from this study, a cropping system of continuous cotton is bet- ter than cotton rotated in systems containing only grasses. Cotton rotated with fescuegrass caused a TABLE 6. INCREASE IN YIELDS OF SEED COTTON PER ACRE DUE TO FERTILIZER AND CROP ROTATION Figure 14. Continuous cotton receiving no fertilizer pro a 3-year average of 770 pounds of seed cotton per acre. decrease in yields over continuous cotton in 1 tically all cases. l All of the cropping systems containing a leg produced higher cotton yields than continuous cot The cropping system most recommended for i‘ Gulf Coast Prairie is a 5-year system of 3 yea Dallisgrass and White clover followed by 2 ‘g of cotton. This cropping system not only prod ' . a high increase in cotton yields but also fits in f with the livestock program throughout the Coast Prairie. A 3-year cropping system of first-year oats-Hu and Sudan, second-year Hubam and Sudan and t year cotton produced higher cotton yields than?‘ of the systems tested, but because of the diffi encountered in the establishment of the forage this system is not recommended as highly as i cropping systems containing Dallisgrass and I clover. A 2-year cropping system of first-year Hu Sudan followed by second-year cotton is the I choice cropping system recommended for the . The type of cropping system used must be 1, on the individual farmer’s needs and the acres hi‘ Average yields of seed cotton per acre, 1955-57 Increase in yields due to: l Continuous Rotatedl Fertilizer Crop rotation Fertilizer ‘ Fertilizer cotton cotton Continuous Rotated (mp m; 0-0-0 770 1030 250 16o 45-0-0 960 1250 190 240 320 5m 90-0-0 870 1080 100 50 - 210 310 0-30-0 860 1220 90 190 360 45g: . 45-30-0 920 1390 ‘I50 360 470 519-; 90-30-0 880 1430 110 400 550 660 90-30-30 950 1300 180 270 350 530‘ 90-30-60 1 150 1360 380 330 210 590g ‘Cotton in a 3-year cropping system of 2 years Dallisgrass-White clover, 1 year cotton. l8 able for crop rotation. A 5-year cropping sys- .. of a 3:2 ratio requires 3 acres of pasture for 2 acres of row crops. A 3-year cropping system :1 ratio requires 2 acres of pasture for every 1 fly-of row crops, and a 2-year system of 1:1 ratio ires l acre of pasture for every l acre of row Qt‘ Cotton Fertilizer Tests An additional 3 x 2 factorial fertilizer test with '0 replications was carried out at the same time e major test. This test used two cropping sys- one of continuous cotton, and the other a 3- 5 cropping system of 2 years Dallisgrass-White .r and 1 year cotton. ainfall during the years in which the test was gliucted was low and in all probability the response ffertilizer treatments and cropping systems was than could be expected under normal condi- . This was especially true in 1957, Table 1. eltapine 15 cotton was planted during the test, general management was the same as in the test. The test was started in 1953 and had been in pro- y; ion for 5 years by 1957. The first cycle of the cropping system was not completed until 1955. cotton test was lost in 1953, and no yields were ined for that year. -57 are given in Table 5. l - j TINUOUS COTTON “f- he results given in Table 5 show that very low 5s were obtained from continuous cotton receiving ertilizer. The average yield was only 770 pounds ed cotton per acre for the 3-year period 1955-57, ' re l4. Yields were almost doubled when cotton rotated with 2 years of Dallisgrass-White clover ; received fertilizer treatments of 90-30-0 per acre. e was a 550-pound-per-acre increase in cotton s because of the cropping system, and an addi- al 110 pounds because of the fertilizer. gf more interest are the relative effects of nitro- 1 phosphorus and potassium. In continuously in cotton, potassium was the most effective ele- tin increasing yields, Table 6. Nitrogen was Second most effective element in increasing yields p phosphorus, third. A fertilizer application of -60 per acre resulted in an average increase of pounds of seed cotton per acre, Figure 15. The 'lizer treatment of 090-30-30 resulted in only a 180- d increase in yields. he high increase in yields caused by potassium l» usual on Lake Charles clay soil as it is medium igh in native potassium. For the past 50 years, ever, the area in which the test was conducted The yields obtained from Figure ‘l5. Continuous cotton receiving a yearly fertilizer treatment of 90-30-60 produced a 3-year-average increase in yields of 380 pounds of seed cotton per acre over nonfertilized continuous cotton. There was a 270-pound increase in yields due to the 60 pounds of potassium (K20) compared with the cotton receiving a fer- tilizer treatment of 90-30-0. has been planted in row crops. It is believed this 1s the reason continuous cotton responded so well to potassium. The response to nitrogen was not as pronounced as the response to potassium. The application of 45 pounds of nitrogen produced 190 pounds of seed cotton per acre more than the nonfertilized cotton, Figure 16. This represents the production of ,4 pounds of seed cotton for each pound of nitrogen applied. The 90-0-0 treatment produced only 100 pounds of seed cotton per acre more than the check treatment. However, the cotton in the plots receiving this treatment was taller, produced more foliage and maintained a greener color than the other plots. But these plants did not set a majority of the cotton bolls. Figure ‘l6. of 45-0-0 per acre per year produced a 3-year-average increase in yields of ‘I90 pounds of seed cotton over continuous nonfertilized cotton. This fertilizer treatment was the most economical in the continuous cotton fertilizer test. Continuous cotton receiving fertilizer treatments 19 Cotton rotated with Dallisgrass and White clover Figure 17. receiving no fertilizer produced a 3-year average of 1,030 pounds of seed cotton. This represented a 34-percent increase in yields over continuous nonfertilized cotton. All of the rotated cotton plots with- stood drouth periods better, were better able to set cotton bolls and were later in maturing than were continuous cotton plots. An application of 30 pounds of phosphorus (P205) per acre resulted in an average increase of 90 pounds of seed cotton per acre. When phosphorus (P205) was applied in fertilizer treatments of 45-30-0 and 90-30-0 per acre, an average increase of 150 and 110 pounds of seed cotton was produced, respectively. The results of the test show that a complete fer- tilizer of 90-30-60 should be applied to obtain the highest yields of cotton under similar conditions to those which prevailed during this experiment, es- pecially when the land has been in row crops for several years. The second highest yields produced by continuous cotton were made with a fertilizer treatment of 45-0-0 per acre per year. ROTATED COTTON The increase in yields caused by fertilizer was much higher in cotton following Dallisgrass and White clover than in continuous cotton, Table 6. Figure 18. Cotton rotated with Dallisgrass and White cl fertilized yearly with 90-30-0 produced a 3-year average of 1, pounds of seed cotton per acre. This yield represented a 400-poa increase in yields due to fertilizer as compared with rotated co receiving no fertilizer; a 550-pound increase in yields due to rotation as compared with continuous cotton receiving the s, fertilizer treatment; and a 620-pound increase due to fertilizer - crop rotation as compared with continuous nonfertilized cotton. Nitrogen was more effective in increasing yields thy phosphorus. Potassium did not increase cotton yie in rotated cotton. Fertilizer applications of 90-30- and 90-30-60 decreased yields 130 and 70 pounds seed cotton per acre, respectively, over cotton 1 ,9 ceiving fertilizer treatments of 90-30-0. The .1; ' amount of potassium (K20) applied to continu cotton increased yields 200 and 270 pounds per a respectively. Nitrogen and phosphorus gave the highest retu in cotton yields when they were applied togetl Applications of 90-30-0 produced the highest aver yield obtained in the test, producing 1,430 pou of seed cotton per acre. The second highest yi was obtained from a fertilizer treatment of 45-3, which produced 1,390 pounds of cotton. This ;. increases of 400 and 360 pounds of seed cotton t acre, respectively, over rotated cotton receiving if TABLE 7. THE INFLUENCE OF CROPPING SYSTEMS ON CORN YIELDS Treatment Years in Bushels of shelled corn per acre number system Cropping system 1953 1954 1955 1956 1957 Ave - No nitrogen 8 Continuous Continuous corn 10.9 25.8 30.9 18.8 32.5 23. 9 1st Dallisgrass-White clover ' 2nd Dallisgrass-White clover 3rd Dallisgrass-White clover . 1st Corn 9.6 27.9 25.0 29.1 43.9 27. 2nd Corn 8.7 19.9 34.4 32.2 47.6 28. 6O pounds nitrogen per acre a Continuous Continuous corn 15.9 37.2 38.8 30.3 52.2 as. 9 1st Dallisgrass-White clover ' 2nd Dallisgrass-White clover 3rd Dallisgrass-White clover » 1st Corn 8.9 37.2 47.8 33.1 67.2 38 2nd Corn 12.6 37.5 38.0 36.2 60.0 36. izer, and an increase of 660 and 620 pounds of ‘lj- over the continuous, nonfertilized cotton, lies 17 and 18. These two treatments coincide iwith the fertilizers used in the major test and votton fertilizer recommendation for the Gulf Prairie of 60-30-0 per acre per year. tton in rotation with Dallisgrass and White _t inade considerably higher yields than contin- _ aCOLILOII, Table 6. The increase in yields varied 18 to 62 percent. The continuous nonfertilized produced an average of 770 pounds of seed per acre, while the cotton in the rotation sys- Qeceiving no fertilizer produced 1,080 pounds of pcotton. This represented a 34-percent increase tton yields due to the cropping system. ~he increase in yields caused by the cropping u was much higher in those systems receiving horus fertilizer than those receiving only nitro- 1 This is believed to be due to two factors: (1) moval of phosphorus from the soil by the White and (2) the nitrogen fixed in the soil by the n The addition of 30 pounds of phosphorus Q5) per acre to the cropping system of 2 years llisgrass-White clover and l year of cotton pro- i» 360 pounds more seed cotton per acre than the ; treatment produced on continuous cotton. ~ e highest increase in yields caused by the crop- asystem was in the plots receiving fertilizer treat- a of 90-30-0 and 45-30-0, which produced an ase of 550 and 470 pounds, respectively, of seed in per acre over continuous cotton receiving the B} fertilizer treatments, Figure 18. The lowest se was obtained from plots receiving fertilizer ents of 90-30-60. The high increase in yields ‘_._ by crop rotation is partly due to the large lnts of high quality organic residues produced allisgrass and White clover, while continuous n tillage practices offer little opportunity for ‘eturn of residues of organic material to the soil. ese fertilizer recommendations should not be except in locations where the soil and climatic 'tions are similar to those which prevailed during experiment. The Texas Agricultural Extension Service Leaflet .“General Fertilizer Recommendations for the been PER ACRE PER YEAR 70 I“ courmuous conu NO unrnoeen _._ __ so LBS. rmaoseu- ---- -- corm m ROTATION warn DALLISGRASS, wan‘: ctovea I FIRST YEAR conn / NO NlTRoGEfl -o—av—r—n /‘ so LBS. mrnoee~-- / secouo YEAR con» / " no n|rRoce~----_ ,' x 6O LBS. NITROGEN—---— O7 O I U’! O l A O I 0| O I BUSHELS OF SHELLED CORN PER ACRE N) Q I IO "- O I I l I I I953 I954 I955 I956 I957 Figure ‘l9. The influence of cropping systems of Dallisgrass, White clover and nitrogen on corn yields. Gulf Coast Prairie and Coastal Marsh” can be used successfully for making fertilizer recommendations in the area, but because of the wide variation in nutrient levels, soil tests should be made to obtain more definite and economical fertilizer recommenda- trons. INFLUENCE OF DALLISGRASS-WHITE CLOVER AND NITROGEN FERTILIZER ON CORN YIELDS Corn Yields The corn yields obtained during the 5 years of the experiment are shown in Table 7 and Figure 19. Because of insufficient or poor distribution of rain- fall and unavoidable lateness of planting or replant- EFFECTS OF CROPPING SYSTEM OF DALLISGRASS-WHITE CLOVER ON YIELDS OF CORN RECEIVING NO NITROGEN AND 6O POUNDS Nitrogen per acre, pounds ‘I956 1957 Average Croppingiisystem None 60 None 60 None 6O y Bushels of shelled corn per acre i, ous corn 18.8 30.3 32.5 52.8 25.6 41.6 ' r corn following 3 years Dallisgrass-White clover 29.1 33.1 43.9 67.2 36.5 50.2 i year corn following 3 years DaIIisgrass-White clover 32.21 36.21 47.6 60.0 39.9 48.1 j-year corn in 1956 followed 2 years of DalIisgrass-White clover. 21 Figure 20. Land in continuous corn receiving no nitrogen fer- tilizer not only produced low corn yields but also failed to produce weeds. ing necessitated by bird damage, 10w to medium yields were obtained during the 5 years of this test. High infestations of sugarcane borers and ear- worms caused considerable reductions in yields for 1953-56. During this time Texas Hybrid 30 corn was planted. In 1957 Texas Hybrid 34 corn was planted. In that year there was no loss caused by‘ earworms and relatively little damage caused by sugar- cane borers. The high yields obtained in 1957 as shown in Table 7 are believed to be partly due to Texas 34 corn which is a new yellow corn hybrid developed particularly for the Gulf Coast Prairie (l3). Prior to 1957 Texas Hybrid 3O was the rec- ommended corn hybrid for the area The cropping systems tested containing corn were continuous corn and a 5-year system of 3 years of Dallisgrass and White clover and 2 years of corn. These systems received the same management prac- tices as those used in the cropping systems containing cotton. One-half of each plot was fertilized each year with 60 pounds of nitrogen per acre and the other half received no nitrogen. All the plots received a total of 30 pounds of phosphorus (P205) per acre per year. The 5-year cropping system of Dallisgrass and White clover completed its first cycle in 1957. From 1953-55 Dallisgrass and White clover showed little effect upon increasing corn yields over continuous corn, Table 7. 22 , CROP ROTATION Figure 21. Land in continuous corn receiving 60 pounds I nitrogen produced 181/; pounds of grain per acre for every poo of nitrogen applied over continuous corn receiving no nitrogen. ‘_ In 1956-57 the effect of crop rotation became a parent in increasing corn yields, Table 8. In pl‘ receiving no nitrogen fertilizer, the crop rotation ' creased corn yields 42 percent for first-year corn a 56 percent for second-year corn following Dallisgr and White clover over continuous corn. The pl receiving 60 pounds of nitrogen per acre produc an average increase in corn yields (bf 21 and l?) p cent, respectively. NITROGEN FERTILIZER Applications of 6O pounds of nitrogen per f, increased continuous corn yields 62 percent, Figu 20 and 21, and first-year corn and second-year c0 following Dallisgrass and White clover 38 and ’ percent, respectively. a The combination of crop rotation and nitrog fertilizer was more effective in increasing corn yiel than either Dallisgrass and White clover or nitro fertilizer alone. First and second-year corn follow' Dallisgrass and White clover that had received nit gen fertilizer produced an average increase in yiet ' of 96 and 88 percent, respectively, over the nonf tilized continuous corn. - is Recommendations for Gulf Coast Prairie Dallisgrass and White clover are recommended I a soil improvement crop for corn as well as for cott Field observations showed an improvement in I 22. Severe cracking of Lake Charles clay soil in con- ” corn plots caused by drouth. Cracks measured 6 feet deep. was relatively little cracking in corn plots which had been with Dallisgrass and White clover. The rotated corn plants - no stress because of lack of moisture as continuous corn ‘showed. jcal condition of the soil in the plots with Da1lis- j and White clover in the system as compared i continuous corn plots. The moisture holding ity of the soil appeared to be better in corn following Dallisgrass and White clover than in , Qontinuous corn plots. There was not so much 'ng during drouth periods, and the corn did not , nearly the stress due to lack of moisture as in ontinuous corn plots. Infiltration also seemed improved, Figure 22. LITERATURE CITED 1. Atkins, I. M., Gardenhire, J. H. and Porter, K. B. Oats for grain, winter pasture and other uses. Texas Agr. Exp. Sta. Bul. 929. 1959. 2. Bonnen, C. A. Cotton statistics for Texas, 1947-57. Texas Agr. Ext. Ser.; Texas Agr. Exp. Sta. M.P. 144. 1957. 3. Bockholt, A. ]., Rogers, j. S. and Collier, ]. W. Corn hy- brids for Texas. Texas Agr. Exp. Sta. Bul. 878. 1957. 4. Carter, W. T. The soils of Texas. Texas Agr. Exp. Sta. Bul. 431. 1931. 5. Cheaney, R. L., Weihing, R. M. and Ford, R. F. The effect of various rates and frequencies of application of rock and super-phosphate on' the yield and composition of forage on a Lake Charles clay loam soil. Soil Science Society of America Proceedings Vol. 20, No. 1. ]an., 1956. 6. Holt, E. C. Dal.lisgrass. Texas Agr. Exp. Sta. Bul. 829. 1956. 7. Holt, E. C. Small grains for forage. Texas Agr. Exp. Sta. Bul. 944. 1959. 8. Thornton, M. K. Fertilizers and their use. Texas Agr. Ext. Ser. Bul. 167. 9. Reynolds, E. B. Cotton production in Texas. Texas Agr. Exp. Sta. Bul. 938. 1959. 10. Riewe, M. E. and Smith, J. C. Effect of fertilizer placement on perennial pastures. Texas Agr. Exp. Sta. Bul. 805. 1955. 11. Gulf ryegrass. Texas Agr. Exp. Sta. L. 407. 1958. 12. Israel sweetclover. Texas Agr. Exp. Sta. L. 399. 1958. 13. Texas 34, a new hybrid for the Gulf Coast. Texas Agr. Exp. Sta. L. 313. 1956. ACKNOWLEDGMENTS Acknowledgment is made to M. J. Norris, associate agron- omist, Substation No. 23, McGregor, project leader for Project H-719; E. R. Cozart, former junior agronomist, Substation No. 3, Angleton, who assisted in conducting the tests in 1953-55; and to the Phillips Petroleum Company, which furnished the ammonium sulfate fertilizer used in this test. 23 i mm 0mm I "us: wasntnous | nu new Lnoanonnzs 4 cooruunuo snnous Location oi field research units oi the Texas Agricultural Experiment Station and cooperating agencies OPERATION CRGANIZATION Research results are carried to Texas farmers. ranchmen and homemakers by county agents and specialists of the Texas Agricultural Ex- tension Service Sonja” 2 WQ5QLIPCL yd j 0m OPFOLU 2 PO9FQ66 State-wide Research The Texas Agricultural Experiment Station A is the public agricultural research agency oi the State of Texas. and is one of the. A parts of the A&M College oi Texas. IN THE MAIN STATION, with headquarters at College Station, are 13 subj; matter departments, 3 service departments, 3 regulatory services and l_ administrative staff. Located out in the major agricultural areas of Texas it 2O substations and 1O field laboratories. In addition, there are 13 coopera stations owned by other agencies. Cooperating agencies include the J Forest Service, Came and Fish Commission of Texas, Texas Prison Syst U. S. Department of Agriculture, University of Texas, Texas Technolo College, Texas College of Arts and Industries and the King Ranch. S“ experiments are conducted on farms and ranches and in rural homes. THE TEXAS STATION is conducting about 4-50 active research projects, grou in 25 programs, which include all phases of agriculture in Texas. Am these are: ‘ Conservation and improvement of soil Beef cattle Conservation and use of water Dairy cattle Grasses and legumes Sheep and goats Grain crops Swine Cotton and other fiber crops Chickens and turkeys Vegetable crops Animal diseases and parasites Citrus and other subtropical fruits Fish and game . Fruits and nuts Farm and ranch engineering i Oil seed crops Farm and ranch business i’ Ornamental plants Marketing agricultural produ; Brush and weeds Rural home economics Insects Rural agricultural economics I Plant diseases I Two additional programs are maintenance and upkeep, and central servi AGRICULTURAL RESEARCH seeks the WHATS. the WHYS. the WHENS. the WHERES and the HOWS of hundreds of problems which confront operators of farms and ranches. and the many industries depending on or serving agriculture. Workers of the Main Station and the field units of the Texas Agricultural Experi- ment Station seek diligently to find solutions to these problems. ,