; LIBRARY, campus. W 7/ 315-727-12M-L18 TEXAS AGRIBIJETURAL EXPERIMENT STATIIIN B. YOUNGBLOOD, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS BULLETIN NO. 365 SEPTEMBER, 1927 DIVISION OF AGRONOMY imam m1. an 1192x100 I wwwmmv CROP REFXWWIN THE BLACKLAND REGION OF CENTRAL TEXAS AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. O. WALTON, President STATION STAFFT ADMINISTRATION : _ *B. YOUNGBLOOD, M. S., Ph. D ,_ Director A. B. CoNNER, M. S , Acting D_irecto_r R. E. KARPER, B. S., Acting Vice-Director J. M. SCHAEDEL, Secretary_ M. P. HQLLEMAN, JR., _Chief Clerk J. K. FRANCKLOW, Assistant Chief ,Clerk CREsTER HIGGS, Executive Assistant B. NEBLETFE, Technical Assistant C. CHEMISTRY: _ _ G. S. FRAPS, Ph. D., Chief; State Chemist E. C. CARLYLE, B. S., Chemist S. E. AsEuRY, M. S., Assistant Chemist WALDO H. WALKER, Assistant Chemist VELMA GRAHAM, Assistant Chemist _ ATHAN J. STERGES, B. S., Assistant Chemist R. O. BROOKE, M. S., Assistant Chemist T. L. OGIER, B. S., Assistant Chemist J. G. EvANs; Assistant Chemist I0LA NIILLER, Assistant Chemist _ GEORGE SAMUEL CRENsRAw, A.B., Assistant Chemist HORTICULTURE: , Chief H. NEss, M. S., Berry Breeder RANGE ANIMAL HUSBANDRY: J. M. JONEs. A. M., Chief; Sheep and Goat Investigations J. L. LUSH, Ph. D., Animal Husbandman; Breeding Investigations W. H. DAMERoN, B. S., _Wool Grader ENTOMOLOGY: _ F. L. THOMAS, Ph. D., Chief; State Entomologist _ H. J. REINIIARI), B. S., Entomologist R. K. FLETCHER, M. A., Entomo ogi_st W. L. OWEN, JR., M. S., Entomologist FRANK M. HULL, M. S., Entomologist J. C. GAiNEs, JR., M. S.. Entomologist _ FRANKLIN SHERMAN. III, M. S., Entomologist F. F. BIBBY, B. S., Entomologist _ S. E. McGREooR, JR., Acting Chief Foulbrood Inspector A. B. KENNERLY, Foiilbrood Inspector GiLLls GRAHAM, Foulbrood Inspector AGRONOMY: " E. B. REYNoLns, M. S., Chief _ A. B. CoNNER, M. S., Agronomist; Grain Sorghum Research _ R. E. KARPER, B. S., Agronomist; Small Grain Research _ P. C. IVIANGELSDORF, Sc. D., Agronomist i_n charge of Corn and Small Grain Investi- gations _ D. T KILLoIJcII, M. S., Agronomist; Cotton Cotton Root Rot Breeding H. E. REA, Agronomist; Investigations E. C. CUSHING, B. S., Assistant in Cro s P. R. JOHNSON, B. S., Assistant in Soi s VETERINARY SCIENCE: **M. FRANcIs, D. V. M., Chief H. SCHMIDT, D. V. M., Veterinarian J. D. JoNEs, D. V. M , Veterinarian PLANT PATHOLOGY AND PHYSIOLOGY: J. J. TAUBENHAUS, P . ., Chi L. J. PEssIN, Ph. D., Plant Pathologist and Laboratory Technician W. J. BAcII, M. S., Plant Pathologist J. PAUL Lusx, S. M., Plant Pathologist B. F. DANA, M. S., Plant Pathologist FARM AND RANCH ECONOMICS: L. P. GABBARD, M. S., ‘e *B. YOUNGBLOOD, M. S., Ph. D., Farm and Ranch Economist G. L. CRAWFORD, M. Si, Marketing Research Specialist V. L. CQRY, M. S., Grazing Research Botanist ***T. L. GASTON, JR., B. S., Assistant; Farm Records and Accounts ***J. N. TATE, B. S., Assistant; Ranch Records and Accounts RURAL HOME RESEARCH: JEssIE WHITACRE, Ph. D., Chief SOIL SURVEY: ***W. T. CARTER, B. S., Chief H. W. HAWKER, Soil Surveyor E. H. TEMPLIN, B. S., Soil Surveyor T. C. REITcR, B. S., Soil Surveyor BOTANY: H. NEss. M. S., Chief PUBLICATIONS: A. D. JACKSON, Chief SWINE HUSBANDRY: FRED HALE, M. S., Chief DAIRY HUSBANDRY: , Chief POULTRY HUSBANDRY: R. M. SHERWOOD, M. S., Chief ****AGRICULTURAL ENGINEERING: MAIN STATION FARM: G. T. McNEss, Superintendent APICULTURE (San Antonio): H. B. PARKS, B. S., Chief A. H. ALEX, B. S., Queen Breeder FEED CONTROL SERVICE: F. D. FULLER, M. S., Chie PEARcE, Secretary ROGERS, Feed Inspector W001), Feed Inspector KIRKLAND, B. S., Feed Inspector NORTHCUTT, JR., B. S., Feed Inspector SIDNEY D. REYNoLns, JR., Feed Inspector P. A. MOORE, Feed Inspector S. D. J. H. W. H K. L. W. D SUB STATIONS N0. 1, Beeville, Bee County_: R. A. HALL, B. S.. Superintendent N0. 2, Troup, Smith County: W. S. HOTCIIKISS, Superintendent No. 3, Angleton, Brazoria County: R. H. STANSEL, M. S., Superintendent No. 4, Beaumont, Jelferson County: R. H. WYcIIE, B. S., Superintendent No. 5, Temple, Bell County: _ HENRY DUNLAVY, M. S., Acting Super- intendent No. 6, Denton, Denton County: P. B. DUNKLE, B. S., Superintendent No. 7, Spur, Dickens County: R. E. DICKSON, B. S., Superintendent No. 8, Lubbock, Lubbock County: D. L. JoNEs, Superintendent FRANK GAINEs, Irrigationist and Forest N urseryman No. 9, Balmorhea, J. J. BAYLES, B. Reeves County: S.. Superintendent Teachers in the School of Agriculture Carrying M. S., Associate Professor of Horticulture D., Professor of Entomology G. W. AnRIANcE. V5. BILSING, Ph. 1A5 oI-‘Septembcr 1, 1927 *On leave. _ _ ****In cooperation with the No. 10, Feeding and Breeding Station, near College Station, Brazos County: R. M. SIIERwooD, M. S., Animal Husband- man in Charge of Farm L. J. McCALL, Farm Superintendent No. 11, Nacogdoches, Nacogdoches County: H. F. MoRRIs, M. S., Superintendent ***No. 12, Chillicothe, Hardeman County: J. . UINBY, B. S.. Superintendent ***J. C. TEPHENS, M. A., Junior Agronomis No. 14, Sonora, Sutton-Edwards Counties: E. W. THOMAS, B. S.. Superintendent W. L. BLACK, D. V. M., Veterinarian V. L. CoRY, M. S., Grazing Research Botanist ***Q_ (}_ BABQOQK, B. S., Collaborating Entomologist O. L. CARPENTER, Shepherd No. 15, Weslaco, Hidalgo County: W; H. FRIEND, B. S., Superintendent M. IVICPHAIL, B. S., Entomologist No. 16, Iowa Park, Wichita County: E. J. WILsoN, B. S., Superintendent Cooperative Projects on the Station: Ph. D., Professor of Marlceting and Finance ScoATEs, A. E, Professor of Agricultural Engineering . P. SMITH, B. S., Associate Professor of Agricultural Engineering **Dean, School oFVeterinai-y Mediciue. ***In cooperation with U. S. Department of Agriculture School ‘of Agriculture. / SYNOPSIS It is common knowledge that y-ields of cotton in the Black- land region of Central Texas are gradually declining. The almost continuous cropping of these soils to cotton year after year without much, if any, elfort being made to maintain or increase their productiveness by the use of fertilizers and manures, crop rotations, or the prevention of soil washing, has resulted in a reduction in the productiveness of a region once thought to be inexhaustible in its fertility. The use of fertilizers has not been successful in restoring these soils to their original productivness. Rotation or changing of crops on the land appears to offer the most promising immediate solution of the problem. Rotation of crops distributes the labor, helps to keep down weeds, controls insect pestsand crop diseases, and makes possible the production of feed crops for home use or the production of livestock. Cotton, corn, wheat, and oats produced larger~yields in rotation than when grown continuously on the same land year after year as shown in 11 years of experiments with several rotations at Temple, Texas. Yields of cotton have been doubled; yields of corn increased 87 per cent; wheat, 55 per cent; and oats, 17 per cent by rotations, as compared with continuous cropping. Rotation of crops reduced root rot of cotton from 39.7 to 4.8 per cent. The crops in the‘ three-year rotation of cotton, corn, and oats brought the highest comparative net profit per acre, $15.96, annually for a period of six years. Cotton planted on the same land continuously showed an average yearly comparative net profit of $7.33 per acre; corn planted contin- uously, $2.32 per acre; oats planted continuously, $2.25 per acre; and wheat planted continuously, $2.02 per acre. c CONTENTS PAGE Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Purpose of Cropping Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6 Method of Conducting the Work . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7 Experimental Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. '7 Yield‘ of Cotton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Effect of Rotation on Root Rot of Cotton . . . . . . . . . . . . . . . . .. 9 Yield of Corn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11 Yield of Wheat . . . . . . . . . .§ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11 Yield of Oats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13 Yield of Cowpeas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14 Yield‘ of Sudan Grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Yield of Grain Sorghum (Feterita) . . . . . . . . . . . . . . . . . . . . . . .. 15 Discussion of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15 Value of Crops in Cropping System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Summary . . . . .- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 xemuutrumi. a MEUHAFILOAB 41F 111333-33! BULLETIN NO. 365 ' v SEPTEMBER, 1927 CROP ROTATION IN THE BLACKLAND REGION OF CENTRAL TEXAS E. B. REYNOLDS AND D. T. KILLOUGH The Blackland region of Central Texas has been noted for the pro- ductiveness, or fertility of its soils, as shown by the large, consistent, and dependable yields of cotton. When these soils were first put into cultivation, it was commonly believed they would not wear out, that they were practically inexhaustible. The almost continuous culture of cotton on these black waxy soils for the last fifty years without proper effort either to maintain, or to increase the productiveness has led to a noticeable decrease in yield. Records are at hand which show that these soils are not as productive now as they were when first put into cultivation. ' A Table 1 gives the yields of cotton in Texas by 10-year periods from 1866 to 1925, inclusive, which were taken from the yearbooks of the United States Department of Agriculture and the United States cen- sus reports. These data show in a general way that the yield of cot- ton in the State, including the Blackland region, is gradually decreas- ing. The yields of cotton of the State as a whole and of the Black- land region for the period 1899 to 1925, inclusive, are given in Table 2, which show still more clearly the decline in the fertility of the soil. The yields reported for the Blacklands were calculated by L. P. Gab- bard, Chief, Division of Farm and Ranch Economics of this Station. The yields for the entire State were taken from the yearbooks of the United States Department of Agriculture. Seven-year moving aver- ages were made. from the data on yield in Table 2. These averages show that the yield of cotton in the Blacklands has a distinctly down- ward trend. This matter is discussed in more detail in Circular No. 39 of this Station entitled “Cotton Production in Texas.” Although the yields of cotton on the soils of the Blackland region are decreasing, the decline cannot be attributed entirely to the deple- tion of the plant-food material in the soil. At least part of the de- crease in yield has been due to losses caused by the root rot of cotton. These black waxy soils have not lost permanently their original pro- ductiveness. They are still potentially fertile and may be restored to their original productiveness by the use of proper methods of manage- ment. Yields of cotton on the Experiment Station at Temple, as re- ported herein, show that as large average yields of cotton in rotation without fertilizers were made in 1914 to 1921 as were made in Texas as a Whole or in the Blackland during any previous decade. The use of fertilizers on these black soils has not given consistently good re- sults. The results of fertilizer tests have been somewhat erratic; 6 BULLETIN NO. 365, TEXAS AGRICULTURAL EXPERIMENT STATION sometimes excellent results are obtained, but more often they are in- different or negative. Table 1.—Yields of cotton in Texas per acre, by 10-year periods, 1866 to 1925, inclusive. Period Pounds of Lint 1866-1875 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . 226 1876-1885 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . 192 1886-1895 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 1896-1905 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 1906-1915 . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 1916-1925 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Table 2.——Average yield of lint cotton per acre in Texas and in the Blackland Region of Texas . 7-Year Moving Average Blackland Year Texas Region Blackland _ ‘ Texas Region Pounds Pounds Pounds Pounds 1899 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 223 . . . . . . . . . . . . . . . . . . . . . . 1900 . . . . . . . . . . . . . . . . . . c . . . . . . . . . . . . . . 226 299 . . . . . . . . . . . . . . . . . . . . . . 1901 . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . 159 201 . . . . . . . . . . . . . . . . . . . . . . 1902 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 148 191 173 215 1903 . . . . . . . . . . . , . . . . . . . . . . . , . . . . . . . .. 143 181 178 218 1904 . . . . . . . . . . . . . . . . . . . , . , . . . . . . . . . . . 183 222 165 193 1905 . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . 164 187 170 196 1906 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 242 167 190 1907 . . . . . . . . . . . . . . . . . . . . , . , . . . . . . . . . . 130 129 166 188 1908 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 196 219 167 187 1909 _ . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . 125 148 173 196 1910 . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . .. 145 168 163 187 1911 . . . . . . . . . , . . . . , . , . . . . . . . . . . . . . , .. 186 217 170 196 1912 . . . . . . . . . . . . , . . , . . , . . . . . . . . . . . . . . 206 249 163 187 1913 . . . . . , . . . . . . . , . . . . 4 . . , , . . . . . . . . .. 150 182 168 194 1914 . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . .. 184 191 166 193 1915 . . . . , . . . . . . . . . . . . . . , , . . . . , . . . . . .. 147 157 156 180 1916 . . _ . . . . . . , . . . . . . . . . , . . . . . . , . . . . .. 157 193 147 164 1917 . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . .. 135 162 150 166 1918 . . . . . . . . . . , . . . . . . . . . . . . . , . , . . . . .. 115 125 137 154 1919 . . . . . . . , , . . . . . . . . . . . . . . . . . . . . . . .. 140 139 135 151 1920 . . . . . . . . . . . . . 4 . . . . , . . . . . . . . . . . . .. 174 196 134 . . . . . . . . . .. 1921 . . . . . . . . . . . . . , . , . . . . . . . . . . . . . . . . . 98 107 135 . . . . . . . . . . . 1922 . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . .. 130 135 134 . . . . . . . . . .. 1923 . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1924 . , . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . 138 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1925 . . . . . . . . . . . .~ . . . . . . . . . . . . . . . . . . . . . 113 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PURPOSE OF TESTS WITH CROPPING SYSTEMS For the purpose of studying the effect of difierent cropping systems on the yields of the crops grown, and to find a suitable rotation for the Blackland region of Central Texas, several different cropping sys- terns, including a four-year rotation of cotton, cowpeas, corn, and wheat, and continuous plantings of cotton, corn, oats, and wheat, were started in 1914 at Substation No. 5, Temple, Bell County, Texas. The other cropping systems reported 011 were begun in 1915, with the exception of the two-year rotation of corn and wheat, which was be- gun in 1921. ' There are several advantages to be gained in using suitable rota- tions or cropping systems. Among these may be mentioned: (a) rota- iimiiumxfiafl; n. we. - i» 1112;11- CROP ROTATION IN BLACKLAND REGION OF CENTRAL TEXAS 7 don of crops aids in the control of insect pests and plant diseases, as or instance, the root rot of cotton; (b) weeds may be controlled by p_ e rotation‘ of crops; (c) rotation or changing of crops on the land ermits the use of crops that improve the land; (d) rotation of crops ~ rmits a better distribution and more efficient use of labor; and (e) arger yields of crops result from these beneficial effects. There‘ are ther advantages of crop rotation but these are perhaps the most im- rtant. METHOD OF CONDUCTING THE WORK In the experiments with different cropping systems reported in this pulletin, the methods of culture, including the time and method of lowing the land; the time, method, and rate of seeding; time and _ethod of cultivation; and varieties of crops were alike for both rotated _v d non-rotated crops, as far as seasonal. conditions and facilities would ermit. ‘For instance, the same variety of corn was used in all of the i topping systems where corn was grown. The corn was planted in all the cropping systems as nearly as possible on the same date and was 'ven uniformcultivation as far as practicable. -Other crops in the ‘ opping systems were treated in a. similar manner. "é; The following cropping systems were tested: 1 Continuous cotton (every year on the same land). Continuous corn (every year on the same land). Continuous wheat (every year on the same land). Continuous oats (every year on the same land). A four-year rotation of‘ cotton, cowpeas, corn, and wheat. A four-year rotation of cotton, cowpeas, corn, and Sudan grass. A three-year rotation of cotton, corn, and oats (Sudan grass lows on stubble). A three-year rotation of cotton, corn, and sorghum. A two-year rotation of corn and wheat. . ‘:- —. zl n .". a _ . . '2 t. , f. . . . "i n 2 3. 4 5 '6 '7 1 8 9 EXPERIMENTAL DATA The data secured in conducting the work with the several cropping (stems are grouped and discussed under the different crops grown. it yields of cotton in all of the cropping systems are assembled in 11= table, where the yields may be compared. The yields of the other Ops, corn, wheat, and oats, are treated in a similar manner. Cowpeas, Sudan grass, and grain sorghum (feterita) were not grown tinuously, but these crops were included in rotations for which are reported. Yield of Cotton in Difierent Cropping Systems i; Five of the nine cropping systems tested at Temple included cotton. ese are: a Continuous cotton (on the same land every year). g2. A four-year rotation of cotton, cowpeas, corn, and wheat. 8 BULLETIN NO. 365, TEXAS AGRICULTURAL EXPERIMENT STATION Ennmkom EoU win . . . . . . .. 2:, 2w 3Q mww mom S: m“ m»; m2 wwm . . . . . . . . . . . . . . . . . . . . . . . . 1.245300 “cofifioh QwQTvEsF 3x0 ,1 . a .. . E . =30 www . . . . . . 13m wmm 22 Rm mom mwm aw owfl 7mm mmm I ....: . . . . . . . . . . . . . . ... . . . . . A5300 ncofimfifi hmo>|wwkak mmwéw cmusm \ FSU . mmoQBoU mwm . . . . . . . . m3 mmm mm mow www 5m Ev mmfi Em wwm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A6300 \ “cosmgoa, Eva-knot $0.55 EoU \ . K . , \ . . \ k .1 yl .\ .. WwQQKoU mww mwm 5w mam mmm 8N . :5 2a m»; m8 ma“ w? 2K . . . . . . . . . . . . . . . . . . . . . . . . . . ASSoU ucofifiog Ewzisom m3 D; 8 w: w: 2; 3N m: 3 a: mom R3 2: . . . . . . . . . . . . . . . . . . . . . 453cc w=o==s=ou .24 .2: .34 52A .2: Q3 .23 i: Q3 QEA i: .34 .25 _ $.12 $32 . Qmmhw>< vmm$>< $2 a: $2 32 82 2i w-mfl :2 22 22 32 Efiwam mEQQEU bwwznofi 39?: . 4 . $235.9? wianohudcohvtzv znmohoa 3Q cofiou in: we @953 E wECWILm QEmH CROP ROTATION IN BLACKLAND REGION OF CENTRAL TEXAS 9 3. A four-year rotation of cotton, cowpeas, corn, and Sudan grass. 4. A three-year rotation of cotton, corn, and oats. ' 5. A three-year rotation of cotton, corn, and sorghum. y The yields of cotton obtained in these cropping systems for the 11- : year period, 1914 to 1924, inclusive, are reported in Table 3. Yields i continuous cotton, and in the four-year rotation of cotton, cowpeas, _ corn, and Wheat. During this period, continuous cotton made an average yearly yield of 147 pounds of lint to the acre, While cotton in 5 the four-year rotation produced 286 pounds, or nearly twice as much as the continuous cotton. _ For the 10-year period, 1915 to 1924, inclusive, yields were secured _from the five cropping systems. For these 10 years, cotton in the four-year rotation of cotton, cowpeas, corn, and Wheat, made the high- est average yield, 285 pounds of lint to the acre, while continuous cotton g produced only 142 pounds to the acre annually. Cotton in the four-year rotation of cotton, cowpeas, corn, and Sudan grass produced an aver- E age annual yield of .243 pounds of lint, and cotton in the three-year rotation of cotton, corn, and oats produced an average annual yield of 2'76 pounds per acre, during the 10-year period. Effect of Rotation on Root Rot of Cotton As stated, rotation of crops, together With clean cultivation, aids in f the control of insects and plant diseases. The cotton grown in the various cropping systems was observed during the growing season and notes taken on the appearance of root rot. A record was kept of the percentage of the total number of plants in each cropping system that Y died from attack by root-rot fungus. The study of root rot here re- ferred to was confined to the counting of dead plants, but Dr. J. J. Taubenhaus of this Station has made extensive studies on root rot of ‘ cotton in the various cropping systems, which will be reported in other I publications. _ ' he percentage of the total number of cotton plants that died of lroot-rot disease in the several cropping systems for the 11 years, 1914 .,_ to 1924, is given in Table 4. It will be observed that the rotated cot- {ton in every case did not have as much root rot as did the continuous cotton. In fact, rotation of crops practically controlled, although it did not eradicate, the disease. In the four-year rotation of cotton, cowpeas, corn, and wheat, only 4.8 per cent of the cotton plants were “killed by root rot, for the 11-year period, 1914 to 1924; while in con- tinuous cotton, 39.7 per cent of the plants died from the disease. In the three-year rotation of cotton, corn, and oats, the loss from the dis- ease was 6.3 per cent for the 9 years, 1916 to 1924; while in the cot- on planted continuously on the same land for this period, the loss jas 31.9 per cent. The yield of cotton, however, ‘is not necessarily low in all cases when - _-he percentage of root rot is high, since the disease frequently develops _ were obtained every year in only two of the cropping systems, namely,’ 10 BULLETIN NO. 365, TEXAS AGRICULTURAL EXPERIMENT STATION Mwfi Nfiw 5m “an m3 vb. 9% R» we “an N6 3w QM on 0d. w...“ LO l\ &,\°._. on we mh 0.2 2w w... m2“ ofiA 0.2 m; 9w m? o. m; i: LO N fin we m.» o.” n5 m.» ca mfw ma 5% 9m é 9o 9% ESQMQOW E00 . . . . . . . . . . . . . . . . . iOfiOU “c0532 QNQTUwQSP. 3x0 EoU . . . . . . . . . . . . . . . . . GOSOU E0353 bwwhéohnk 32m 525m . . . . . . . . . . . . . . . . .GO30U . . . . . . . . . . . . . . . . . flofioU nGOUNQOh gnaw-knob . ‘ . . . . . . . . .GOuwOO nDOW-CUQOU . $2 aha 5H 235$ v2 H m H ~aw>|m hwowé \_. Qmw$>< $2 Q2 $2 S2 82 22 mm: 22 f2 2i 32 Ewwwam miimflopU Qcfiwzm mfiaaoho Qfifiwbmu E Q9. doc“ 3 nflzx cofioo Mo omfinoouomla» 22mm. -- »-,-.1' "xv x" q . m1 ‘vi mwvwfi‘ W”""1":*sr!"~"' CROP ROTATION IN BLACKLAND REGION OF CENTRAL TEXAS 11 after the fruit on the cotton has practically matured. In such a case the yield would not be reduced nearly as much in proportion to the percentage of root rot as it would if the root rot had developed and killed the plants at an earlier stage of growth. It is certain, how- ever, that the larger yield of rotated cotton was due in a large measure to the smaller percentage of root rot present. The effectiveness of crop rotation in controlling root rot disease is dependentlargely upon the clean cultivation given the crops in the rotation, thereby destroying various weeds which act as carriers of the disease. For this reason, weeds should not be allowed to grow in corn or on oat stubble, after the crop has been harvested. Yield 0f Corn in Dilferent Cropping Systems Corn was grown in six different cropping systems as follows: 1 Continuous corn (every year on the same land). _ 2 Four-year rotation of cotton, cowpeas, corn, and wheat. 3. Four-year rotation of cotton, cowpeas, corn, and Sudan grass. 4 Three-year rotation of cotton, corn, and oats. 5. Three-year rotation of cotton, corn, and sorghum. 6. Two-year rotation of corn and Wheat. The yields of corn obtained in these cropping systems appear in Table 5. Yields for 11 years were obtained from only two methods of crop- ping, continuous corn and corn in the four-year rotation of cotton, cowpeas, corn, and wheat, for the entire period of the experiment ex- cept in 1917, an extremely dry year with only 20.75 inches of rainfall, j when corn was a failure in all of theDcropping systems. The rotated corn produced an average yield of 33.4 bushels, and the continuous corn 19.3 bushels, to the acre annually for the 11 years, including 1917. There were only three years, 1921, 1922, and 1924, in which yields . of corn were obtained in all of the six cropping systems. For these ;, three years, corn in the four-year rotation of cotton, cowpeas, corn, i, and Wheat, and in the two-year rotation of corn and wheat, produced ‘almost identical yields, these being 37.4 and 37.8 bushels to the acre, respectively. The continuous. corn made an average yield of 20.2 Zbushels to the acre for the same period. During the seven years, 1915, 1918, 1919, 1920, 1921, 1922, and 1924, corn in the two 3-year rotations produced practically the same ‘average yields, these being 34.3 and 33.7 bushels to the acre. Yield of Wheat in Different Cropping Systems Wheat was grown in the following cropping systems: 1. Continuous wheat (every year on the same land). 2. Four-year rotation of cotton, cowpeas, corn, and Wheat. 3. Two-year rotation of corn and wheat. The two-year rotation of corn and wheat was begun in 1921. l2 BULLETIN NO. 365, TEXAS AGRICULTURAL EXPERIMENT STATION v3 l\ N 9mm 5m in». v.5 Ndm 5m v.3 f: 5m 1mm i: 5m 5m s” 9mm mam am ANN 5m 5m 0.3 5mm 5m >3 U)‘ Nb. v.8“ 5m TN ~04 MA 5m HEN wQN in. 0a..“ baa 5m 0&0 5m 000:3 . . . . . . . . . . . . . . . . . . . . . . QuhO “c0353 .80 03F Essmpow . . . .500 00300 HGOSMQO» hmow-oohmm. 5m O . . . . . . . . . . . . . . . . . . . . . . .E.~OU c0300 E0333 Lmuhkvwbmm. 32m 035w 5:80 c0300 “c0632 hmvhisovm . . . . . . 4 . . . . . . . . . . CQOO wmOmmfiwmOu vN|NN|HN § -NN-§3 LwPTm $-32 002T: 0929/4 $8 m mmi mm“: $2 0N2 m2: 22 £2 E2 32 53am 36020 903E? M05008“. Qcmhwwmw E 000w $0 E00 m0 mmonwnn E E271...“ 030B CROP ROTATION IN BLACKLAND REGION OF CENTRAL TEXAS 13. The yields of wheat obtained are reported in Table 6. Wheat in the four-year rotation produced larger yields than the continuous wheat in seven of the nine years. For the nine years, 1916. to 1924, inclu- sive, Wheat in the four-year rotation made an average yearly yield of 15.1 bushels to the acre; while continuous wheat produced 11.2 bushels to the acre for the same period. Table 6.——Yield in bushels of wheat per acre in different cropping systems. Wheat in 4-year _ Rotation of Wheat 1n 2-year Continuous Cotton, Cow eas, Rotation of Year Wheat Corn an Corn and Wheat Wheat Bushels Bushels Bushels 1916 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14.2 15.3 . . . . . . . . . . . . . . .. 1917 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.7 8.2 . . . . . . . . . . . . . . . . 1918 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12.0 16.4 . . . . . . . . . . . . . . .. 1919 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18.0 17.5 . . . . . . . . . . . . . . .. 1920 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 8.8 . . . . . . . . . . . . . . . . 1921 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7 5.9 2.2 1922 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7.2 12.6 14.4 1923 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10.0 19.5 23.8 1924 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 20.3 32.0 26.2 y Average, 1916-1924 . . . . . . . . . . . . . . . . 11.2 15.1 . . . . . . . . . . . . . . . . Average, 1921—l924 . . . . . . . . . . . . .. 10.8 17.5 16.7 Yields of wheat in the three cropping systems wrere obtained each of the four years, 1921 to 1924, inclusive. Wheat in the four-year rotation produced an average annual yield of 17.5 bushels; in the two- year rotation, 16.7 bushels; and continuous Wheat, 10.8 bushels, to the acre for the four years. Yield of Oats in Different Cropping Systems The results with oats are reported in Table 7. Oats Were included in only two cropping systems, oats planted continuously on the same land and a three-year rotation of cotton, corn, and oats. This work was conducted during- the years 1914 to 1924, inclusive, but continu- ous oats were not grown in 1915. For the 10 years of the experiment, rotated oats produced an average yrield of 32.0 bushels and continu- ously planted oats, 27.3 bushels to the acre a year. In_ three of the te11 years, 1919, 1921, and 1922, continuous oats produced larger yields than oats in the rotation; while in 1924, the yields of the two crop- ping systems were practically the same, being 31.0 and 31.3 bushels to the acre, respectively. These results show that there is not as much difference between the yields ot‘ rotated and continuously planted oats as there is between the yields of rotated and continuously planted cot- ton, corn, and wheat. ' 14 BULLETIN NO. 365, TEXAS AGRICULTURAL EXPERIMENT STATION Table 7.—-Yield in bushels of oats, per acre, grown continuously and in a three-year rotation. Oats in a 3-year Continuous Rotation of Year Oats Cotton, iCorn, and Oats Bushels Bushels 1914 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0 10.0 1916 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.7 37.3 1917 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8 12.1 1918 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.8 19.7 1919 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66.7 65.0 1920 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 16.7 1921 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46.4 17.0 1922 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36.0 29.1 1923 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38.4 81.3 1924 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.0 31.3 Average, 1914—1924* . . . . . . . . . . . . . . . . . . . . . . . . . . 27.3 32 .0 *The year 1915 was omitted because continuous oats were not grown that year. Yield of Cowpeas Cowpeas were grown in two cropping systems: in a four-year rota- tion of cotton, cowpeas, corn, and wheat, and in a four-year rotation of cotton, cowpeas, corn, and Sudan grass. Yields of cowpeas in the latter rotation were obtained only two years, 1915 and 1916, and for this reason yields are not reported for cowpeas in this rotation. - The yields of cowpeas in the four-year rotation of cotton, oowpeas, corn, and Wheat are given in Table 8. It will be noted that yields were low in all years except in 1915 and 1924, when they were 11.1 and 21.5 bushels per acre, respectively. The average yield during the 1O years 1914 to 1924, omitting 1920, when yields of seed were not obtained, was 5.3 bushels per acre. This average yield is low and unprofitable, as will be shown later. Cowpeas are almost as susceptible to the root-rot disease as cotton, and the low yields of cowpeas in some years resulted partly from the fact that the plants were killed by the disease. Guar, also a legume crop, has given excellent results at the Tem- plfe Station. It is especially valuable as a soil improvement crop, be- iimig practically resistant to the root-rot disease, and no doubt could be :substituted for cowpeas in the rotation with good results. Yield of Sudan Grass Sudan grass was grown in only one cropping system, a four-year rotation of cotton, cowpeas, corn, and Sudan grass. The yields of Sudan grass hay secured in this rotation for the nine-year period 1916 to 1924, omitting 1923, are given in Table 8. Yields were low in 1916, 1918, and 1920. The average yield for the nine years was 1.8 tons of hay per acre, which also is rather low. CROP ROTATION IN BLACKLAND REGION OF CENTRAL TEXAS 15 Yield of Grain Sorghum (Feterita) Feterita, a grain sorghum, was included in only one cropping sys- tem, a three-year rotation of cotton, corn, and feterita. Feterita was grown in this rotation during the nine years, 1915 to 1924, except in 1923 (Table 8). The yield of grain was low in 1918, 1922, and was a failure in 1915 and 1924. The average yield of grain for the nine years was 9.0 bushels, and for the seven years, 1916 to. 1922, inclusive, 11.6 bushels to the acre. The average yield of forage during the nine years was 2.7 tons to the acre annually; and for the seven years, 1916 to 1922, inclusive,- 3.3 tons. Table 8.—Yield per acre of cowpeas, Sudan grass, and grain sorghum (feterita) in rotations. Grain Sorghum Year Cowpeas Sudan Grass _ Grain _ Forage Bushels Tons Bushels Tons 1914 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1915 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11.1 2.5 0.0 0.0 1916 . . . . . . . . . . . . . . . . _ . . . . . . . . . . . .. 3.0 0.8 13.6 4.1 1917 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1.8 1.5 13.3 v 2.7 1918 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.6 0.2 6.1 0.6 1919 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4.1 1.2 13.4 4.4 1920 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.9 13.1 5.6 1921 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3.0 2.5 15.5 4.4 1922 . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0.6 3.8 6.1 1.6 1923 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1924 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 21.5 2.7 0.0 0.7 Average . . . . . . . . . . . . . . . . . . .. 5.3 1.8 9.0 2.7 DISCUSSION OF RESULTS The average yields of all the crops grown in the several cropping systems are assembled in Table 9 for the purpose of studying the re- sults as a unit. The yields of each crop are given for the longest period in which the crop was grown in all of the cropping systems. For example, cotton was grown in all of the cropping systems which contained cotton during 10 of the 11 years, and yields are reported for the 10 years. This method of analysis enables one to make a direct comparison of the yields of each crop in the different systems. It will be noted (Table 9) that the rotated crops produced larger yields than continuous cropping in every case. The largest average yields of cotton (285 pounds) and wheat (15.1 bushels) were produced in the four-year rotation of cotton, cowpeas, corn, and wheat. Cotton in the four-year rotation of cotton, cowpeas, corn, and wheat yielded 285 pounds of lint per acre; as compared with a yield of 243 pounds of lint in the four-year rotation of cotton, cowpeas, corn, and Sudan grass; 2'76 pounds of lint in the three-year rotation of cotton, corn, and oats; 215 pounds of lint in the three-year rotation of cotton, corn, and sorghum; and only 142 pounds of lint on land planted con- tinuously to cotton. 16 BULLETIN NO. 365, TEXAS AGRICULTURAL EXPERIMENT STATION Table 9.—Average yield per acre of cotton, corn, wheat, oats, cowpeas, Sudan grass, and grain sorghum 1n different cropping systems. _ Yield N0. Years Cropping System Per Acre Averaged Continuous cotton, lbs. of lint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 10 Continuous corn, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.3 11 Continuous wheat, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 .2 9 Continuous oats, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.3 1O Four-year rotation:_ Cotton, lbs. of lint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 1O Cowpeas, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 10 Corn, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.4 11 Wheat, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.1 9 Four-year rotation: Cotton, lbs. of lint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 10 Cowpeas (yield not obtained) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Corn, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 .5 7 Sudan grass, tons of hay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .8 9 Three-year rotation: Cotton, lbs. of lint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 l0 Corn,'bushels . . . . . . . . . . . . . . . . . . . . . . . . ._ . . . . . . . . . . . . . . . . . . 34.3 7 Oats, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.0 1O Three-year rotation:- Cotton, lbs. of lint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 10 Corn, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.7 7 Sorghum (feterita) bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.0 9 Two-year rotation: v Corn, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37.8 3 Wheat, bushels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.7 4 Yields of corn were obtained in all of the methods of cropping which included corn for periods of from three to eleven years. For these periods the largest yields of corn resulted from the two-year rotation of corn, and Wheat; and the three-year rotation of cotton, corn, and oats, the yields being 37.8 and 34.3 bushels to the acre, respectively. The lowest average yield of corn in a rotation, 27.5 bushels, for the seven years, resulted from the four-year rotation of cotton, cowpeas, corn, and Sudan grass. Corn planted continuously on the same land produced only 19.3 bushels per acre, for the 11-year period, 1914 t0 1924. Oats in the three-year rotation of cotton, corn, and oats, produced an average of 32 bushels, and oats planted continuously, 27.3 bushels to the acre for the 10-year period, 1914 to 1924, omitting 1915. For the purpose of studying the different cropping systems on a comparable basis, the average yields of the several crops were given a percentage rating, the yield of the continuous cropping being consid- ered as 100. Percentage ratings of the crops are given in Table 10. From Table 1O it will be noted that the percentage rating of cotton was higher, 201 per cent, in the four-year rotation of cotton, cowpeas, corn, and wheat than in the other cropping systems. The highest rat- ings of corn, 187' per cent, and Wheat, 155 per cent, for athree- and four-year period, respectiveljy, resulted from the two-year rotation of corn and wheat. The three-year rotation of cotton, corn, and oats also "< . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . an}; wmAm hmhm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IP60 vw 3w mmAmw Rdww . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . éofioU “cofiafii kmwwéminu. EWmE figfiw wwgmfiw mwfiw wmdiw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6w 5a :25»! 3c wwm$>< mm} mm»: Si»; . . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . . . Ifiwc we E Hmfim 56m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IEoU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .AMQHPQU “Q0551: ._wv>-@oEF 3.6g $.02“ mvzoé Eflmw Emmfiw . . . . . . . . . . . . . . . . ¢ . . . . . . . . . . . . . . . . . . 13am 5Q E53 3c omm$>< wmé 9%: mmflm . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . ¢ . . IEQAR/ 0mg: nmfim hqwm . . . . . . . ¢ . . . . . . . . ... . . . . . . . . . . . . . . . . . . . IFSU aamm. owNH 265 . . . . . . . . . . . , . . . . . . . . . . . . . . , . . . . . . . 139M300 om. mg wwbmw wmflww . . . . ‘ ‘ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A5300 E0533 bwohsifloh mo. N ww . m: S . S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28.? wEEEEQu . mmfl 5.: wmAi . . . . . . . . . . . . . . . . . . . . 4 . . . . . . 4 . . . Ifiwo wsoscficoU Nwrm oo. a mmfmm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .500 wsoscicoU mmfi w Qiwmw mhbmw . . . . 4 . . . . . . . . . . . . , . . . . . . 4 , . . . . 453cc msossflcou Hausa SmC EoU cofioU Q54 5L cofiosvokm v.64 5L wcpswwfl we wmoU E2505 53am wiirzu wsoncficoU $>O flofiawofl 37H 13oF $30 ._o hex/ah E v.64 3m EmU BULLETIN NO. 365, TEXAS AGRICULTURAL EXPERIMENT STATION 4&2 E; mmi .52 6N2 6:3 6:1 6.23% xi 2B .8“ wEBPQ miaaoho fiszwuz. E mach. Mo 3am 5a o3w> 3n owm~v><|aH~ Bank CROP ROTATION IN BLACKLAND REGION OF CENTRAL TEXAS 19 corn, and wheat, brought a net profit of $12.77 annually for the same = period; While the crops i11 the three-year rotation of cotton, corn, and sorghum brought $12.11 per acre annually for the six-year period. Cotton grown continuously showed an average yearly net profit of $7.33 Yicper acre; corn grown continuously, $2.32; oats grown continuously, $2.25; wheat grown continuously, $2.02. Each of the three rotations '1 produced crops which showed a marked increase in money value per acre over the continuous cropping to cotton, corn, oats, and wheat. l These results show that the three-year rotation of cotton, corn, and Toats was the most profitable croppingisystem. It would perhaps be gmore practicable than the other systems, since it is possible to include ‘a soil-improving crop, preferably a legume, in the rotation, planting ‘it as a catch crop after the oats. It may not be possible in some cases for the individual farmer-to plant one-third of his land in cotton; one-third in corn, and one-third ~in oats, each year. Under such conditions, one-half of the land can ~ebe planted to cotton, and the other half planted equally to corn and ‘goats. The land which was planted to cotton this year will then be Qlanted to corn and oats next year. In following such a plan the corn nd oats should be alternated so that neither of these crops will be lanted on the same land more often than once every four years. The qotton, however, would be planted on the same land every other year. xi" ile it is not believed that such a cropping system would be as profit- ble as the three-year rotation mentioned above, it would probably be inch more profitable than planting the same crops continuously on he sameland. ‘_ Any rotation system may be improved by the use of a legume as a tch crop, to be planted on the land after the main crop has been rvested. Good results have been secured at the Substation at Tem- _ e in the three-jyear rotation, during years of favorable rainfall, from lanting the legume, guar, on the land immediately following the re- of the oat crop. The crop of guar was allowed to reach matur- There is usually a certain fairly well fixed amount 0f labor and "uipment available on the farm during the year, and if the one-crop tem of farming is practicedthere will be times when this labor and f pment will be idle and consequently non-productive. If rotations ‘- used, several crops may be grown and, as a result, the labor can _ distributed to a better advantage. If cotton, corn, and oats are i» the oats may be planted in the fall at a time that would not. erfere seriously with the other farm work, and the broadcast growth the oats serves to prevent soil erosion. The land can be prepared ‘_' the corn planted in the spring, which would not interfere with aplanting of cotton. In this way the labor and equipment can be _';o to produce feed or cash crops other than cotton at times when 2o BULLETIN NO. 365, TEXAs AGRICULTURAL EXPERIMENT STATION they could not be used to produce cotton, resulting in a larger net income. - Rotation of crops enables a farmer to grow feeding stuffs which may be fed to livestock such as _cattle, sheep, hogs, or chickens rather than Inarketed directly as grain or forage and thus tend to prevent an over- production of any single commodity. This would again give a better distribution of labor, especially during the late fall and winter Inonths when the farmer would probably be idle a large part of his time if he were practicing the one-crop system of farming, thus resulting in a11 in- crease of income. I If the results of the rotation experiments at Temple prove to be generally applicable to this section of the State, it is evident that the farmer who practices crop rotation is a far better risk as a borrower, ‘than one who plants cotton on the same land continuously. The former can raise the same amount of cotton on less acreage than the latter, and his crops of corn and oats, therefore, represent not substitutes for cotton, but additional security. SUMMARY Data are presented which show that the yield of cotton in the Black- land region of Central Texas is gradually decreasing; yet results ob- tained at the Experiment Station at Temple "with rotations show that yields may be maintained or even increased. Nine different cropping systems were tested at Temple. These in- cluded two 11-year rotations,,tvi'o 3-year rotations, a 2-year rotation, and cotton, corn, oats, and wheat, planted continuously. In every case the crops grown in rotation produced larger yields than the crops planted continuously on the same land. Root rot of cotton was much less prevalent in rota-ted than in cot- ton planted continuously. 1n the four-year rotation of cotton, cow- peas, corn, and wheat, for the 11 years 1911 to 1924, only 4.8 per cent of the cotton plants died from root rot: as compared with 39.7 per cent for cotton planted continuously. In the three-year rotation of cotton, corn, and oats, the loss from the disease was 6.3 per cent for the nine years, 1916 to 1924; while in the cotton planted continuouslyf ‘on the same land for this period, the loss was 31.9 per cent. Cotton in the four-year rotation of cotton, cowpeas, corn, and wheat yielded 101 per cent more lint cotton than did cotton which was grown continuously on the same land. Cotton in a three-yrear rotation of cot- ton, corn, and oats, yielded 94 per cent more cotton than the cotton grown continuously. Corn in the two-year rotation of corn and wheat, yielded S7 per cent more than corn grown continuously; while corn in the four-yfear rota- £1011 0f cotton, cowpeas, corn, and wheat, and corn in the three-year rotation of cotton, corn, and oats, yielded '70 and 56 per cent more corn, respectively’, than did corn grown continuously. i CROP ROTATION IN BLACKLAND REGION OF CENTRAL TEXAS 21 Wheat in the two-year rotation of corn and Wheat, and wheat in the four-year rotation of cotton, coWpeas, corn, and wheat, yielded 55 and 35 per cent. more, respectively, than did the Wheat grown continuously. Oats in the three-year rotation of cotton, corn, and oats, yielded 17 per cent more than oats grown continuously. Oats appear to be benefited less by rotation than cotton, corn, or wheat. The crops in the three-year rotation of cotton, corn, and oats brought a greater comparative net profit per acre than any other cropping sys- tem in the test, being $15.96 per acre a year as against $12.77 average profit for the crops in the four-year rotation of cotton, cowpeas, corn, and wheat. This rotation produced larger yields of cotton and wheat than the other cropping systems, but the average total net profit per i_ acre of the four crops was $3.19 an acre less than the profit from the crops in the three-year rotation of cotton, corn, and oats. Cotton planted continuously showed a comparative net profit of only $7 .33 per acre; corn planted continuously, $2.32; oats planted continuously, . $2.25; and wheat planted continuously, $2.02. In practicing crop rotation several crops may be grown, resulting in - a better distribution of labor and more efficient use of farming imple- ments and other equipment. - The rotation of crops also tends to con- trol crop diseases and insect pests, is an aid in keeping down weeds, 5f and enables the farmer to produce a variety of feed crops which may f be fed profitably to livestock. '