TEXAS AGRICULTURAL EXPERIMENT STATION A, B. CONNER, DIRECTOR College Station, Texas BULLETIN NO. 616 AUGUST 1942 GERMINATION OF COTTONSEED AS AFFECTED BY SOIL DISTURBANCE AND MACHINE ' PLACEMENT OF FERTILIZER H. P. SMITH, M. H. BYROM, H. F. MORRIS _ Division of Agricultural Engineering AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. O. WALTON, President LIBRARY ‘ Siaiian. 1 was éanpgorfiwdw no unofivnammfl .m .5. on» mo mamnmmawmzfi was hapwfiflonU no 5am» 15m 23 ha 3G5 use uoqmflmwu iowflnrfiflu awufinrfiwu was nouns?“ fiouwoo qompsfinfieo mo 33> 03m A mfirwrm Experiments were conducted at College Station and N acogdoches for a five-year period, 1936 to 1940, inclusive, to determine the effect of machine placement of fertilizer and the effect of soil disturbance 0n the germination of cottonseed. When a 4-12-4 commercial fertilizer was placed under the seed at depths of one, two, and three inches below the seed, there was an in- crease in the percentage of‘ emergence and yield as the depth increased. Fertilizer placed directly under the seed at the time of planting injured the root system and in most cases stopped the development of tap roots at the level of the band of fertilizer. \Vhen only the soil was disturbed directly under and at the several depths below the seed the percentage of germination decreased with the depth of the disturbance. Where fertilizer was not applied normal tap roots developed. The best emergence and stands were obtained when the fertilizer was placed two inches to each side and one and two inches below the seed level. As the fertilizer was placed deeper and farther below the seed level than two inches there was a slight decrease in the percentage of emergenc indicating that when fertilizer is placed to the sides of the seed so that the roots of the cotton seedling do not come in contact with the fertilizer, yet close enough for them to get some plant food in the sprouting stage, the fertilizer is beneficial in obtaining better stands. In all of the side placement tests the root systems of the young seedlings were not injured and normal tap roots developed. When only the soil was disturbed two inches to each side of the seed and one, two, and three inches below the seed level, but no fertilizer applied there was very little difference in the percentage of emergence. The percentage of emergence when the soil was disturbed at the side in unfertilized tests was higher than when the soil was disturbed under the seed in all cases at both locations except the three-inch depth at Nacogdoches. Therefore, the results of these studies show that the best germination and emergence is obtained when cottonseed are planted on a firm, undisturbed soil, and that better stands are obtained when ferti- lizer is placed two inches to the sides of the seed and one or two inches below the seed level. CONTENTS Page Introduction 5 Description of Experiments“ 5 Efiects of Fertilizer 8 Effect of under the seed placem-ent of fertilizer 0n percentage emergence and yield 8 Effect of side placement of fertilizer on percentage emergence and yield 16 Effect of Soil Disturbance 25 Efifect of Disturbing the soil under the seed on percentage emer- gence and yield._ - 25 Effect of disturbing the soil to the side of the seed on percentage emergence and yield 27 Summary and Conclusions ______ _- ,-_ 28 GERMINATION OF COTTONSEED AS AFFECTED BY SOIL DISTURBANCE AND MACHINE PLACEMENT OF FERTILIZER By H. P. Smith, Chief, Division of Agricultural Engineering M. H. Byrom, Agricultural Engineer, Divisiom of Agricultural Engineering H. F. Morris, Superintendent, Substation No. 11, Na-cogdoches, Texas* A well prepared and firmly settled seedbed is essential for good germination of cottonseed. In many sections of the Cotton-belt, farmers follow the practice of preparing the seedbed for cotton, long enough before planting time, so that rain will occur in suffcient amounts t0 wet, settle, and firm the soil. The data presented in this bulletin confirm this practice and also show the effect on germination of cottonseed when the fertilizer was placed under and to the side of the seed at various depths and the effect of disturbing the soil at the same placements and depths. In studies on machine placement of fertilizer of cotton by Collins, (1) Cummings, (2), and (3), and Smith (4) unfertilized checks were not used for each separate placement of fertilizer. In this study an unfer- tilized test or check was planted for each placement of fertilizer. DESCRIPTION OF EXPERIMENTS Scope of Experiments: These studies covered a five-year period and were made at College Station and Nacogdoches. The tests were planted in three replicated blocks. In each block a 100-foot row was divided into two 50-foot sections and data collected from each section. The analysis of variance, however, was calculated on the basis of the three replications. Fertilizer: Throughout the experiments a 4-12-4 commercial fertilizer was applied at the rate of 500 pounds to the acre. Variety of Cotton: Startex cottonseed grown at, College Station was used at both locations each year for the experiments. The planting depth and the calibrated number of seed dropped for each 50 feet are shown in Table 1. Fertilizer Placement Machine: The machine used in these experiments shown in Figure 1, was designed and built by the Bureau of Agricul- tural Chemistry and Engineering of the U. S. Department of Agriculture and is fully described in Texas Station Bulletin No. 548, “Machine Place- ment of Fertilizer for Cotton.” *Credit is due Dr. J. C. Gaines of the Division of Entomology for his assist- ance in the statistical analysis of the data contained in this Bulletin. ‘or row was always adjacent to an unfertilized plat. This arrangem College Station N acogdoches i Year - Planting 1 Seed in Planting depth 50 depth in feet in inches inches 193s- ________ __ 114 50o 1 1937-- 11,4 55o 1 193s ' 11,4 700 1 a 1939.--“ 1% 600 1 1940 ............................................... -- 1:54 515 1 6 BULLETIN N0. e16, TEXAS AGRICULTURAL EXPERIMENT STATION Interpretation of Data: Analyses of variance were made using t. dilferent criteria, even though, the plats were not truly randomized each block. It was a systematic arrangement in that each fertilizer p l’ may have caused a biased error but analyses are presented in an eff _, to improve the interpretation of the results. f Homogeneity tests of the error variance- of the several experime indicated heterogeneity, which means that a common error is not vat to test the treatment variance in the combined analyses. In some w: this combined error would be too low and others it would be too 1Q By comparing the treatment variance to the high interaction varian it is safe to assume that the significance found was not due to cha. alone, but due to certain treatments being consistantly better than oth throughout the period. Table 1. Planting depth and calibrated number of cottonseed dropped 1n 50 feet. Rainfall and Seasonal Conditions: The temperature and moisture ditions‘ at the time of planting and immediately following have con. erable effect on the germination of cottonseed and the emergence of lings. Table 2 shows the average mean temperature of the air for R days before planting and ten days after planting. Each year as the were planted the temperature of the soil was determined at the plan i depth (Table 2). The total rainfall during the five days before and ten - 1 after planting is also shown in Table 2. Very little rain fell just be if and after planting in 1937 and 1939. In 1939 at College Station A’ moisture in the soil was insufficient for germination where the soil disturbed under or near the seed. The seed remained in the dry g from April 20 until May 16 before rainfall was adequate for germi tion. f Procedure: At both locations the seedbed was prepared by listing throwing up ridges or beds" with a two-mule walking middlebuster pi This was done three or four weeks before the date of planting so ‘ rains could settle and firm the soil in the ridges. It appeared beat Table 2. Temperature and rainfall during the period 5 days before to 10 days after planting. College Station Planting Y ear date-— April planting planting Average mean Soil Total temperature-Kl‘. tempera- rainfall—in. ~ tnre at —--—-—~ ~—-—-- planting 5- days Uldays Average before after for the planting plant- 15 days ing Nacogdoches 5 days Average mean 1936 _____________ __ 26 75.2 71.4- 72 1.10 1.33 621.6 71.2 68.4 1937 ____________ __ _ 22 72.8 73.4 66 .48 .20 71.6 68.8 619.7 19‘ ____________ __ _ 19 72.2 72.3 67 .73 2265 62.1 70.5 67.7 1939' ____________ __ _ 2O 70.2 68.2 68 .11 .00 65.8 614.8 65.1 1940 _____________ __ 17 68.4 65.6 76 .00 ‘ .59 56.5 65.5 62.5 " 1 Ave ______________ _ . 71.8 70.2 70 i .48 [ 95 63.7‘ 68.2 66.7 temperature-JR 10 days Average before after for the planting planting 15 days planting 5 days_ 10 days planting planting CIEIEISNO$=LOO JO NOLLVNIWH [>19 ‘ In one test all fertilizer was placed two inches to one side and two inches 8 BULLETIN NO‘; 616, TEXAS AGRICULTURAL EXPERIMENT‘ STATION have alternate fertilized rows so that if the plants fed from row to row, conditions would be equal for all the unfertilized plants. For each fertilizer placement test; an unfertilized test, was planted having the same soil disturbance as the fertilized test. EFFECT OF FERTILIZER The major objective in these studies was to determine the effect of machine placement of fertilizer and the effect of soil disturbance on the germination of cottonseed. Tests were planted with the fertilizer placed one, two, and three inches below and directly under the seed. Other tests were planted with the fertilizer placed two inches to each side of the seed and one, two, and three inches below the seed level. '3 below the seed level. The unfertilized test for each placement was planted with the same planter adjustments as the fertilizer test. The fertilizer placements under the seed were in a single narrow band 1.75 inches wide. Effect 0f Under the Seed Placement of Fertilizer on Percentage Emer- gelnce and Yield When fertilizer is placed under cottonseed at the time of planting, the furrow opener for the fertilizer should open a furrow at least two inches deeper than that opened for the seed. After the fertilizer has been deposited in the bottom of the furrow and covered, the seed opener opens a furrow in this soil and the cottonseed are planted in the loose t soil directly above the fertilizer. The distance between the seed and the ‘ fertilizer depends upon the adjustment of the fertilizer and seed furrow a openers. The soil thrown on the (seed to cover them is loose around the ‘ seed, even though press wheels are used to partially press and firm the g soil over the seed. Moisture evaporates rapidly from loose soils, often down to or below planting depth. Such a condition may delay germig nation of seed several days, or until rain occurs. “ Percentage of Emergence: The data in Table 3 show that when fer tilizer was placed at depths of 1, 2, and 3 inches under the seed th average percentage of emergence for both locations was 59.3, 70.9, and 71.9 percent, respectively. This indicates that better germination an ' emergence was obtained when the fertilizer was placed deeper an! farther below the cottonseed. This is shown graphically in Figure 2. Different results were obtained for the unfertilized tests, that is, t' percentage of seed germinating and emerging as seedlings decreased the soil was disturbed deeper under the seed (Table 3 and Figure 2). When only the soil was disturbed at depths of 1, 2, and 3 inches und the seed the average p-ercentage of emergence was 76.5, 72.9, and 70. W,‘ respectively. Figures 3, 4, and 5 tshow growth of cotton roots' sev days after planting for the three depths of fertilizer when placed unwdl GERMINATION OF COTTONSEED 9 the seed. Figure 6 shows growth of cotton roots Where no fertilizer was applied under the seed. In figure 3, it is seen that, when the fertilizer was placed one inch directly under and below the seed, the root of the germination cotton- seed extended only down to the fertilizer. The fertilizer was so close Average percentege nergemee 8 3 3" ' 8' to Belqw Below Below pen eide ‘Q1 ,1“ he]: eide One elde eeel eeed eeei l" below 2" below 3" 591°‘ l" 5'1" [Oil level n“ 1,1,1 need level eeed level Fertilizer plecezneni and eoil dieturbence Figure 2. Graph showing percentage of germination of cottonseed for the fertilized and unfertilized tests at College Station and Nacogdoches. to the seed that as soon as the seed sprouted and root growth started the root immediately came in contact with the band of fertilizer. The roots being young and tender were stunted and growth of the plant was slowed down, thus delaying emergence of the seedlings. In many cases the germinating seeds were so badly affected that they died in the sprouting stage, and this resulted in a lower stand count than on tests where fertilizer was placed two and three inches below the seed. Placing- Table 3. Average pe mentage oi’ emergence of cotton seedlings to the side of the seed and the soil was in 50 feet of row when the fertilizer was placed under and disturbed on the unfertilized tests. College Station - 51890861001168 Ave- ‘. ————~~~ of Fertilizer placement. Test both and soil disturbance Nc. Lutkin fine sandy loam NOTfOIk Sandy 106m 1008.- t one 1936 1937 1938 1939 1940 Ave 1936 1937 1938 1 1939 1940 Ave. 7 I Bands 1.75 inches wide 1 inch below seed" 1 77.0 20.9 71.3 58.7 78.3 61.2 66.5 52.7 60.7 39.8 67.5 57.4 59.3 Unfertilized—soil disturbed _______ _- 2 85.3 48.2 79.8 68.9 74.2 71.3 76.9 73.3 82.7 89.2 86.7 81.7 76.5» 2' inches below seed 3 79.1 40.6 60.8 61.6 74.7 63.4 79.2 79.8 75.8 68.0 89.3 78.4 70.9 Unfer‘tilized—soil disturbed _______ __ 4 80.0 41.6 61.7 77.0 66.1 65.3 77.6 72.2 89.3 73.8 89.8 80.5 72.9 3 inches below seed 5 78.6 50.9 51.0 69.6 70.4 64.1 82.5 85.1 86.3 59.5 85.2 79.7 71.9 Unfertilized—soi1 \ disturbed _______ __ 6 73.2 43.2 45.8 75.4 67.2 61.0 82.7 78.4 81.0 76.3 83.6 80.4 70.7 Bands 2 inches to each side 1 inch below seed 1eve1_ ___________ __ 7 89.8 62.9 93.3 88.4 83.7 83.6 86.4 96.6 87.9 81.1 92.1 88.8 86.2 Unferti1ized—soi1 disturbed _______ __ 8 78.2 46.1 86.1 84.2 ~ 73.9 73.7 77.3 85.4 85.0 85.3 84.3 83.5 78.6 2 inches below seed . level ____________ __ 9 91.6 52.6 85.7 88.9 80.4 78.8 82.0 92.6 91.6 79.0 97.0 88.4 88.6 Unfertilized—soil disturbed _______ __ 10 83.6 53.2 80.5 78.3 71.4 73.4 74.0 815.7 83.1 81.9 85.9 82.1 77.8 3 inches below seed 1eve1_ ___________ __ 11 85.7 4.4.5 85.8 82.0 80.5 77.1 77.4 84.8 96.0 72.1 88.8 83.8 80.5 Unfertilized—soil disturbed _______ __ 12 81.6 46.7 80.0 85.7 76.7 74.1 76-7 78.4 79.3 73.5 81.1 77.8 76.0 In band all on one side of seed 2 inches- below seed 1eve1_ ___________ _- 13 87.4 41.0 78.1 78.3 80.1 73.0 86.3 93.3 86.0 80.6 84.7 86.2‘ 79.6 Unfertilizcd-soil . disturbed _______ _- 14 81.7 58.4 75.3 | 75.5 79.1 74.0 75.6 92.4 76.8 77.4 82.0‘ 80.8 77.4 Difference required between any two means ior significance at the 5 per ' 7 -..r h ‘ ' - i 8.90, .---..------.. ....-----------.--..----.._ 7.57 9.09 01 BIOILVLS JlNEIWIHEI<1XEI TVHILLTHOIHOV SVXELL ‘QTQ 'OI\‘[ NIQEIYYIIIEI g gure 3. Typical root development of cotton seedlings 7 days after planting when fertilizer was placed 1 inch directly below seed. Roots extended only down to the fertilizer. Pigure 5. Root development of seedling 7 days after plent- ing when fertilizer was placed 3 inches directly be- low the seed. '.l‘he roots ex- tended down to the fertilizer with only a few passing through it. cotton GERMINATION OF‘ COTTPONSEED 11 Figure 4. Root development of cotton seedling 7 days after plant- ing when fertilizer was placed 2 inches directly be- low the seed. Roots extend- ed down to the fertilizer with only a few passing through it. Figure 6. Root development of cotton seedling 7 days after plant- ing when soil was disturbed l inch directly below seed but no fertilizer applied. Compare with Figure 3. "the fertilizer deeper and farther below the seed permitted more d-evel0p- ment of the plant before the roots reached the fertilizer, resulting in Lminnnn.“ M. . . Table 4. Analyses of variance of percentage emergence in experiments at College Station and Nacogdoches. Q Mean squares pertaining to- Source 0f variation College Station Nacogdoches 1 _ 1 D-F 19-36 1937 1938 1 1939 1940 1936 1913-7 1938 1939 1 1940' Blocks ........... _- 2 12.08 50.72 273.06 215.31 68.88 1.28 58.24 3=0.75 60-.08 1 274.83 Treatments _________________________________ _- 13 83.551 293.81* 594.98 1 235.961 106_69* 81.021 385.25» 214.701 455.5111 134.791 Error ________________ -- 26 16.68- 10082 83.819 1 41.49 38.80 7.92. 17.91 0.61 29.83 1 8.87 I Total ........................................ -. 41 37.66 160.81 255.17 1 116.88 61.80- 3078 1 136.35 1 75.67 1 166.27 61.77 Combined analyses 1 Mean 1 Mean squares squares, SOHTBB 0f Variation . Source oi variation College ‘1 = Station and DF I College Nacogdoches DF Nacogdoches 1 Station 1 " combined 1 - B1ocks___- 10 i 150.611 ; 85.041 Blocks ____ __ _ __ - 2O 117.831 1 1 Tests_____ 13 1305.551 Treatments ________________________________ __ 13 1 726.271 1 844.271 Years _______ __ 4 3835.461 1 Location ..... -- - 1 9846.821 Years- - --- _____________ __ 4 8321.421 ‘ 829.33 Treat >< years _ 52 117.051 1 , Treat >< location _______________________________ __ 13 2616.241 Treatments‘ >< years" 52 1 147.181 106.751 Location >< years ___________________ -1 _________ __ 4 5259.331 1 1 Years >< location >< treatment ________________ -_ 52 136.571 Error ________________ _____________________ _- 130 i 56.34 14.83 Error ....................... _- - 260 35.58 1 1 Total _____________________________________________ __ 419 218.84 Total ...... -4. _____________________________ __ 209 1 283.31 1 108.24 " . *Significant. _ 1Highly significant. NOLLVrLS 4LNEEWIHEIJIXEI "IVHIILI/IIIOIHBV SVXELL ‘Q19 'ON NLLEVFIHH ZI GERMINATION 0E COTTONSEED 13 better stands than where the fertilizer was placed close to the seed (Fig. 3, 4, 5, and 6). Figures 7, 8, and 9 show root development of fully matured plants at harvest time. Note absence of tap roots where fertilizer was plac-ed under the seed and presence of long tap roots where no fertilizer was applied. A When analyses of variance were applied t0 the detail data the vari- ance for treatment was significant in every year at each location indicat- ing the treatments significantly affected the percentage 0f germination (Table 4). Thus, it appears, that both the shallow placement of fertilizer and the deep disturbance of the soil under the seed at planting time will affect and reduce the germination of cottonseed and the emergence of seedlings. Rate of Emergence. The data in Table 5 shows a definite delay in germination when the fertilizer was placed one inch under the seed at Nacogdoches and seedlings did not emerge as rapidly as where the fer- tilizer was placed at the deeper depth. When the fertilizer was placed one inch under the seed, the average stand at the first, second and third counts was 31, 105, and 331 plants, respectively, but when the fertilizer was placed three inches under the seed the average stand for each of the three counts was 97, 322, and 460 plants, respectively. At College Station this same trend is indicated for each year except 1938. In 1938 a .42 inch rain fell just after planting was completed, and a .77 inch rai11 on the following day. Also a 1.42 inch rain_fell on the day the first count was made. This much rain occurring so soon after planting may have dissolved the fertilizer and diluted the salts sufficiently to reduce the effects of the fertilizer salts on the cottonseed. Yield: At Oollege Station the yield for each of the placements under the seed was 205 pounds of lint per acre for the one-inchidepth; 270 pounds for the two-inch depth, and 284 pounds‘ for the three-inch depth (Table 7 and Fig. 10). The yields increased as the fertilizer was placed deeper. The average for all three depths was 253 pounds against 165 pounds of lint per acre for the three unfertilized tests receiving the soil disturbance. The three fertilized tests yielded 88 pounds per acre more than did the three unfertilized tests‘. At Nacogdoches, the yields for the one-, two-, and three-inch depths was 346, 391, and 407 pounds of lint per acre, respectively (Table 7). As at College Station the yield increased as the fertilizer was placed deeper. The average for the three unfertilized tests was 134 pounds of lint per acre. The three fertilized tests at Nacogdoches gave a yield of 247 pounds of lint per acre more» than the unfertilized tests. Table 8 shows the yield of seed cotton per 100 feet of row on which the analyses of variance were calculated. The same ratio of differences appear in Tables 7 and 8 though one is calculated to show acre yield of lint and the other yield of seed cotton per plat. The yield graphs in 14 BULLETIN NO. 616, TEXAS AGRICULTURAL EXPERIMENT STATION The four cotton roots on left show effect of fertilizer when , fertilizer was placed l inch directly below the seed at the ti A planting. The four roots on right are from unfertilized test ha. the same soil disturbance as those on left. Figure 7. Figure 8. The four cotton roots on the left show effects of fertilizer w_ \ tilizer was placed 2 inches directly below the seed. The fo“ on the right are from unfertilized test having the same soil dis if as those on the left. GERMINATION OF COTTDONSEED 15 The four cotton roots on the left show elfelcts of fertilizer when fer‘ tilizer was placed 3 the right are from as those on the left. Figure 9. inches directly below the seed. The four roots 0n unfertilized test having the same SO11 disturbance Average pounds of eeed cotton per teat. u Below Below Below Each aide p“ “d; Eech eide One eide eeed eeed eeed l" below g» p.10‘ 3" below 8" below eeed level ‘Md 1,7,1 eeed level jeed level Fertilizer pleccnent and soil disturbance Figure 10. Graph showing average pounds of seed cotton harvested from the fertilized and unfertilized tests, at College and Nacogdoches. 16 BULLETIN NO. 616, TEXAS AGRICULTURAL EXPERIMENT‘ STATION Figure 10 are based on the data in Table 8. Table 9 shows the analyses of variance of yield in the experiments; at College Station and Nacog- doches. Table 5. Average rate of emergence of cotton seedlings in 50 feet of row when fertilizer was placed under and below the seed and the soil was dis- turbed under and below the seed. College Nacog- 1~Station dochesi Ave. \ . l Test Germina- —— of i N0. tion i Lufkin both Fertilizer placement and 1 counts* fine Norfolk i loca~ soil disturbance l sandy sandy i, tions i loam loam i I 5 year 5 year i i l Ave. Ave. ‘ “""_*""" i i ' t Bands 1.75 inches wide l I _ i f first \ 47 31 i 40 1 inch below seed ______________________________ __i 1 i second i 173 10a 139 ‘i i third i 352 331 l 342 l i first ; 97 s1 i s9 Unfertilized-soil disturbed ___________________ _- 2 second 292 343 312 ‘ ~ third 418 473 446 first 32‘ 87 6O 2 inches below seed ______ -_, ___________________ __ 3 second 1 204 268 236 third 369 462 410 t first 51 90 70 Unfertilized-soil disturbed- __________________ -_ 4 1 SECOIIG 221 348 284 third i s80 447 414 \ first i 51 9'7 74 3 inches below seed ___________________________ __ 5 ‘ second 322 2'72 l third l s70 460 415 first 49 103 ‘ 76 Unfertilized-soil disturbed_ __________________ _- 6 Second 202 345 274 third 353 462 408 *At College Station the average interval between date of planting and first, second and third counts was 6, 9, and» 20 days, respectively, while at Nacogdoches the average interval was 6, 9, and 17 days, respectively. Effect of Side Placement of Fertilizer on Percentage Emergence and Yield In this series of tests the fertilizer was placed in furrows made with disks set to open furrows two inches to each side of the seed and one, two, and three inch-es below the seed level. This left a strip of firm soil some four inches wide undisturbed on which to plant the cotton- seed. One test was planted where all the fertilizer was placed two inches to one side and two inches below the seed lev-el. For each fertilized test planted an unfertilized test was also planted. Both sets of tests re- ceived the same soil disturbance. Percentage of Emergence: Table 3 shows that as the fertilizer was placed deeper below the level of the seed, there was a decrease in the percentag-e of the total number of seedlings emerging. When the fer- GERMINATION OF‘ CO-TTONSEED 17 tilizer was placed one, two, and three inches below the seed level the average percentage of emergence for both locations‘ was 86.2, 83.6 and 80.5 percent, respectively. The percentage of emergence for the un- fertilized tests with the same soil disturbance was 78.6, 77.8 and 76.0, percent, respectively. For all three depths of fertilizer placement and soil disturbance the fertilizer tests gave a higher percentage of germina- tion and a larger number of seedlings emerging than the unfertilized tests (Fig. 2). Thus it appears that when fertilizer is‘ placed far enough from the seed to prevent injury to the germination, yet close enough for young seedlings to get some plant food, the fertilizer is beneficial, and in- creases the number of cotton seedlings emerging. The data in Table 3 also show that when the soil is not disturbed directly under the seed or too close to the sides and no fertilizer applied there is little change in the percentage of emergence of seedlings as the soil is disturbed deeper below the seed level. The percentage of emergence and the total number of seedlings were slightly lower when all of the fertilizer was placed on one side than when it was divided and equal amounts placed on each side at the same depth. Placing the fertilizer to the sides of the seed did not retard the de- velopment of tap roots of young cotton seedlings (Figs. 11, 12, 13 and 14). Root development of fully matured cotton plants taken from rows where the fertiliz-er was placed to the side is shown in Figures 15, 16 and 17. Placing all of the fertilizer on one side of the plants at the time of planting appears to induce greater root development on the side of the plant next to the fertilizer. This is shown in Figure 18. Difference in growth of plants on the fertilized tests at Nacogdoches is shown in Figures 19 and 20. When analyses of variance were applied to the detail ‘data on the side placement of fertilizer and soil disturbance, it is seen from a study of the data, that at College Station the treatments did not affect the germination in exactly the same manner (Fig. 2) but the variance for treatments was significant when compared t0 the significant interaction (treatment vs. years). This was likewise true at Nacogdoches. In the combined analysis for all years at both locations all interactions were significant and the variance was significant when compared to the inter- action (treatment vs. years)._ Apparently the percentage emergence was high on tests‘, 7 and 9, where the fertilizer was placed 2 inches to each side and two inches and three inches below the seed level. This was consistant throughout the 5-year period at both locations (Table 3). Rate of Emergence: Fertilizer placed to each side of the seed and below the seed level at the various depths did not delay emergence as much as when the fertilizer was placed below and directly under the 18 BULLETIN NO . 6'16, TEXAS Figure 11. Root development of cotton seedling 7 days after plant- ing when fertilizer was placed 2 inches to each side and 1 inch below soil level. AGRICULTURAL EXPERIMENT STATION Figure 1'2. Root development of cotton seedling 7 days after plant- ing when fertilizer was placed 2 inches to each side and 2 inches below seed level. Figure 13. seed (Tables 5 and 6). in emergence when the fertilizer was level as compared with the two- and emergence for the one-inch depth was sli depths. Root development of cotton seedling 7 days after plant- ing when fertilizer was placed 2 inches to each side and 3 inches below seed level. ‘ Figure 14. Root development of cotton seedling 7 days after plant- ing when soil was dis- turbed 2 inches to each side and 2 inches below seed level. Table 6 shows that there was a slight delay placed one inch bleow the seed three-inch depths, yet the total ghtly higher than the deeper GER-MINATION OF‘ COTTONSEED 19 The rate of emergence on the unfertilized tests varied in a similar manner as did the fertilizer tests. The number of seedlings was slightly lower for the unfertilized tests than for the fertilized tests. '.l.‘able 6. Average rate of emergence of seedlings in 50 feet of row when the fertilizer was placed to the side and below the seed level and the soil disturbed to the side and below the seed level. l l l l l l College Nacog- l l l Station doches l Ave. Test Germina- ——————— ~—- l of ‘ No. tion l Lufkin l both Fertilizer placement and l counts* l fine Norfolk l loca- soil disturbance l l ‘l sandy sandy l tions l l loam loam l 5 year 5i year l Ave. Ave. ._.__._.______-i__+-___ l _. l Bands 2 inches to each side l l first l 139 131 l 1:15 I inch below seed level _______________________ -_l 7 second l 320 378 l 349 l third 492 513 l 502 l l l first l 10s 12o l 114 Unfertilized-soil disturbed- __________________ __l 8 second l 271 376 324 ‘ third l 435 48s l 459 l l first l 143 15o j 146 2 inches below seed level _____________________ .._l 9 second ; 266 386 l 326 l l third ‘ 462i 509 l 4:56 l l l l first 12s 10s l 11s Unfertilized-Soil disturbctL __________________ __ 10 second 266 387 326 third 431 455 l 443 l l first 139i 15s l 146 3 inches below seed level _____________________ __ 11 * second 244 391 l 318 ‘ third 454 491 l 47 2 ‘ first 129 112 I 120 Unfertilized-soil disturbed- __________________ __ 12 second 271 344 l 308 third 4:10 44:1 l 44o All on one side of seed ‘ l first 123 153 l 13s 2 inches below seed level _____________________ -_ 13 second 274 386 l 325 third 425 497 l 462 first 116 127 ‘ 122 Unfertilized~soil disturbed- __________________ __ 14 l second 284 3S4 l 334 third 431 466 448 *At College Station the average interval between date of planting and the first, second, and third counts ivas 6, 9, and 20 days, respectively, while at Nacogdoehes the average interval was 7, 9,’ and 17 days, respectively. Yield: At College Station the yield for the fertilizer placement of two inches to each side and one, two, and three inches below the seed level was 320, 287, and 281 pounds of lint per acre, respectively, with an average of 296 pounds of lint per acre (Table 7 and Fig. 10). The three unfertilized tests gave an average yield of 162 pounds of lint per acre. The three fertilized tests yielded 134 pounds of lint per acre more than the unfertilized tests. 2U BULLETIN NO. 6116i, TEXAS AGRICULTURAL EXPERIMENT STATION Figure 15. The four cotton roots on the left show root development when fer- tilizer was placed 2 inches to each side and 1 inch below seed level. The four on right are from unfertilized test having the same soil dis- turbance as those on left. Figure 16. The four cotton roots on the left show root development when fer- tilizer was placed 2 inches to each side and 2 inches below seed level. The four roots on the right are fro m unfertilized test having the same soil disturbance as those on left. GERMINATION OF‘ CO-TTONSE ED Figure 17. The four cotton roots on the left show root development when fer- tilizer was placed 2 inches to each side and 3 inches below seed level. The four on right are from unfertilized test having‘ the same soil dis- turbance as those on left. Figure 18. The four cotton roots on the left show root development when all of the fertilizer was placed on one side-—2 inches to the side and 2 inches below the seed level. The four on the right are from un- fertilized test having same soil disturbance as those 9n left. 22 BULLETIN NO. 616, TEXAS AGRICULTURAL EXPERIMENT STATION Table 7. Average yield. of lint per acre on 50 feet of row for all fertilizer place- ment and soil disturbance tests.* l‘ College Nacog- Station doches —-— ~———~ Ave. 1 Lufkin 0f Fertilizer placement and Test fine Norfolk both soil disturbance No. sandy sandy loca- loam loam I tions 5 year 3 year Ave. Ave. Bands 1.75 inches wide 1 inch below seed ________________________________________ _-. 1 205 346 276 Unfertilized-soil disturbed_ _____________________________ __‘ 2 162 142 152 2 inches below seed ______________________________________ __ 3 270 391 330 Unfertilized _______________________________________________ __ 4 168 132 150 3 inches below seed ______________________________________ -_ 5 284 407 346 Unfertilized——soil disturbed_ _____________________________ __‘ G l 166‘ 127 146 n___lé_nn 1._.___ nnn__ Bands 2 inches to each side A l 1 inch below seed level __________________________________ __ 7 l 320' 375 348 Unfertilized-soil disturbed ______________________________ __ 8 l 160 130 145 l 2 inches below seed level ................................ __ 9 ‘ 2s: 414 s50 Unfertilized-—soil disturbecL ______ __‘ _____________________ __‘ 10 l 162 126 144 3 inches below seed level ________________________________ -_‘ ll l 281 408 344 Unfertilized _______________________________________________ __ 12 l 165 128 146 l All on one side of seed 2 inches below seed level ________________________________ __ 13 295- 365 330 Unfertilized—soil disturbed ______________________________ __l 14 l 172 12s I 150 *Calculations based on 290.4 part of acre per plat and 35 percent lint. At Nacogdoches, the average yield for the fertilizer placement, of one, two and three inches below the seed level was 375, 414 and 408 pounds of lint per acre, respectively, with an average of 399 pounds of lint per acre (Table 7). The three unfertilized tests which received the same soil disturbance but no fertilizer gave an average yield of 128 pounds of lint per acre. The fertilized tests yielded 271 pounds of lint per acre more than the unfertilized tests. When all of the fertilizer was placed two inches to one side and two inches below the seed level, the average yield was 295 pounds at College Station and 365 pounds of lint per acre at Nacogdoches. The average yield of the unfertilized tests was 172 and 128 pounds of lint per acre for College Station and Nacogdoches, respectively. When the average yields of the three under-the-seed placements and the three-side-and-below the seed level placements are compared, the data in Table 7 show that the latter placements gave higher yields by 43 pounds of lint per acre at College Station and 18 pounds at Nacogdoches. The data also shows that at both locations, when 4-12-4 commercial fertilizer was applied at the rate of 500 pounds per acre two inches to each side and at one inch and . two inches below the seed level, slightly higher yields were obtained than GERMINATION OF OOTTONSEED 23 when the fertilizer was placed one and two inches below and under the seed. A study of Table 7 shows, however, that at both locations there was very little difference in the yield when the fertilizer was placed three inches below and under the seed and the side placement at the same depth below the seed level. The variance due to treatments was significant in every year at each location, indicating that the treatment (fertilized vs. unfertilized) caused a significant difference in the yield (Tables 8 and 9). An examination of the yield graph (Fig. 10) shows that the treatment variance was caused by a high yield in all fertilized tests. Fertilizer applied in any manner increased the yield. Among the fertilized tests, the yields was low when the fertilizer was placed one inch directly under the seed, but this dif- ference in yield was not significant. '.I.'able 8. Average yield of seedcotton in 100 feet of row when. the fertilizer was placed under and to the side of the seed and the soil was disturbed on the unfertilized tests.* | College Nacog- ; , Station doches L f i Ave. u kin i of Fertilizer placement and ‘ Test fine Norfolk g both soil disturbance No. sandy sandy l loca- loam loam f tions 5 year 5 year l Ave. Ave. Bands 1.75 inches wide ' 1 inch below seed ________________________________________ n; 1 1 4.04 6,93 5.51 Unfertilized-soil disturbe-d_ ______________________________ __* 2' I 3.18 2 37 3.02 2 inches below seed ______________________________________ __ 3 5.31 7,39 6,60 Unfertilized—soil disturbed _______________________________ -; 4 3.23 2.65 2,96 3 inches below seed ______________________________________ __‘ 5 5.5a 8.21 ass Unfertilized-soil disturbed- _____________________________ __ 3.2.3 2,69 2,95; Bands 2 inches to each side 1 inch below seed level __________________________________ __ T 5.86 7.56 6.71 Unfertilized-soil disturbed ______________________________ __ 8 3.13 2.62 2.88 2 inches below seed level ________________________________ __ 91 5.69 8.36 7.03 Unfertilized—-s0il disturbed ______________________________ __ 10 3.17 21.56 2,57 3 inches below seed level ________________________________ __ 11 , 5.52 8,325 6,89 Unfertillzed-soil disturbed- ............................. -- 12 . 3.31 2.58 2.94 All on one side of seed 2 inches below seed level _________________________________ _. 13' l 5 so 7.36 6.58 Unfertilized-soil disturbed- _____________________________ __I 14 i 3.38 2,53 198 e l Difference required between any two means for significance at the 5% level- ___________________________________________________________ __ 6e .78 2.4a *Calculations based on 145-2 part of acre per plat. j: Table 9. Analyse of variance of yield in experiments at College Station and Nacogdoches. s; Mean squares pertaining to— w _____ __ __ g G Source of variation College Station Nacogdoches 3 DF 193s 1937 1 19-33 I 1939 1940 193s 1 1937 l 193s 1 1939 I 1940 E 1 _ a 1 . Z Blocks ______________________________________ _. 2 1.87 4.53 1.34 l 3.03 1 4.34 .12 1 3.37 131.59 22 .1 79 9 . I i m Treatments ________________________________ __ 13 31.001 3.331 8.1211 4.1111 6.321 14.221; 17.481 28.6011 23.741| 30-341 Error _______________________________________ -. 26. .20 .39 .23 1 .74 .27 .03 .19 .54 I .03 1 .24 g . , 1 1 . Total _______________________________________ _- 41 1.17 1.53 2.80 1.92 1 2.41 4.57 5 82 10.32 7 55 1 10-05 E . | to 11> Combined analyses Q E O 1 Mean E y Mean squares squares, I-E Source of variation —-—————-——- —— Source of variation | College g ‘ A s Station and h, DF (Jollege Nacog- DF Nacogdoches t-l Station doches combined b’ l“ "wfl “SM” ' l s Blocks ................................... .. 1o 3.131 3.621 Blocks ............. _; ............................. __ 20 I 4.381 s1 1 Treatments ______________________________________ __‘_ 13 112.131 a Treatments _________________________________ __ 13 21.591 109.991 Years _____________________________________________ _ - 4 731-351 g - Location_ _______________________________________ _- 1 84.561 p1 Years _______________________________________ __1 4 49.141 39.071 Treatments >< years _____________________________ -- 52 -47 7; . Treatments >< location _________________________ _- 13 19.451 "'1. Treatment >< years _______________________ __ 52 .821 1.101 Location >< years ______________________________ _- 14-841 (r. ‘ Years >< location >< treatments _______________ -_ 52 1 1.40 E EITQI’ _________________________________________ __ 130 .37 .21 EITOI’ ____________________ __- ______________________ __ 260 1 .33 g Total ____________________________________________ -_ 419 5 75 »-1 Total ______________________________________ -_‘ 209 2.87 8-26 1Highly significant. GERMINATION OF GOTTONSEED 2.5 EFFECTS OF SOIL DISTURBANCE To place fertilizer in the soil at the same time cottonseed are planted, it is necessary to first open furrows and disturb the soil to place the fertilizer either below the seed or to the sides and below the seed level. It has been observed that cottonseed planted on a firm, well settled soil germinated more rapidly and gave better stands than when planted in a loose soil. It appeared, therefore, that all the differences in germination between different fertilizer placements and an average check could not be attributed to the effects of the fertilizer. Consequently, for each fer- tilizer test planted an unfertilized test was planted having the same soil disturbance as the fertilized test. Efiect of Disturbing the Soil Under Seed on Percentage Emergence and Yield In the unfertilized tests the soil was disturbed one, two, and three inches directly under and below the seed as was done to place the ferti- lizer under the seed. Figure 19. Field at Nacogdoches June 23, 1939, showing difference in growth of cotton plants on fertilized and unfertilized tests. A. No fertilizer applied but soil disturbed at planting time two inches to each side and one inch below seed level. Test No. 8. B. Fertilizer applied at the rate of 500 pounds per acre, two inches to each side and two inches below the seed level. Test No. . C. No fertilizer applied but soil disturbed same as B. Test No. 10. 26 BULLETIN NO. 616, TEXAS AGRrIC-ULTURAL EXPERIMENT‘ STATION Percentage of emergence: The data in Table 3 shows that for College Station the percentage of seedlings emerging averaged 71.3, 65.3 and 61.0 percent for the one-, two-, and three-inch depths of disturbance un- der the seed, respectively. The difference between the one-and three-inch depth was significant. The results at Nacogdoches gave a similar trend but were not significant. That is, that as the soil was disturbed deeper the percentage of emergence decreased somewhat. The average for both locations was 76.5 for the one-inch depth, 72.9 for the two-inch depth, and 70.7 for the three-inch depth. A study of the data for the unfertilized tests in Table 3 shows that when the soil is disturbed and left loose and cottonseed are planted in a loose soil, germination is affected and fewer seedlings emerge as the depth of the disturbance and the amount of loose soil increases. It appears, therefore, that disturbing soil under the seed will reduce germination of cottonseed and the effect is increased with the depth of the soil disturbance. Rate of Emergence: A study of the data in Table 5 and Figure 2, show that at College Station deep disturbance of the soil cause more delay in emergence than the shallow disturbance. At the first count an average of 97 plants had emerged for the one-inch depth, 51 for the two- inch depth and 49 for the three-inch depth. At Nacogdoches the aver~ age stand at the first count was 81 for the one-inch depth, 90 for the Figure 20. Difference in growth of cotton plants on fertilized and unfertilized test at Nacogdoches September 17, 1940. Man at left is standing on row 3 where fertilizer was 111M395 2 ilmhes directly under the seed. Man at right is standing on unfertilized row (row 4) which had the same soil disturbance as row 3. Row 5 at right in picture had fertilizer placed at 3 inches directly under the seed. GERMINATION OF‘ COCPTONSEED 27 two-inch depth, and 103 for the three-inch depth. The difference in soil type probably accounts for the reversal in the results at the two loca- tions. The Norfolk sandy loam soil, Nacogdoches, flowed back and filled the furrow opened in placing the fertilizer better than did the stiffer Lufkin soil at College Station. Consequently, the seed were not planted at as constant a depth as at Nacogdoches. Yield: The average yield for all unfertilized tests where the soil was disturbed und-er the seed was 165 and 134 pounds of lint per acre for College Station and Nacogdoches, respe-ctively (Table 7). The depth of soil disturbance did not significantly affect the yield when the unfer- tilized tests are compared with each other (Tables 7 and 8 and Fig. 10). Effect of Disturbing the Soil to the Side of the Seed on Percentage Emergence and Yield Soil was disturbed two inches to the sides of the seed at depths of one, two and three inches below the seed level. Percentage Emergence: The data in Table 3 and Figure 1, show that for the unfertilized side disturbed soil tests the percentag-e of emergence was more uniform for the different depths at College Station than at Nacogdoches. Germination, however, was slightly better at Nacogdoches than at College Station. At College Station the average percentage of emergence was 73.7, 73.4, and 74.1 perc-ent, respectively, for the one-, two-, and three-inch soil disturbance below the seed level. The average percentage of emergence at Nacogdoches was 83.5, 82.1 and 77.8 percent, respectively, for the three depths. None of these differences were sig- nificant at the 5 percent level. Figure 21. A commercial tractor mounted planter with fertilizer attachment for placing the fertilizer to the side and below the seed level. 28 BULLETIN NO. G16, TEXAS AGRICULTURAL EXPERIMENT STATION Rate of Emergence: The data in Table 6 shows that disturbing the soil to the sides one, two, and three inches below the seed level and no fertilizer applied, had little effect on the rate of emergence 0f cotton seedlings. The average stand of plants at the first count for both loca- tions, was 114 for one-inch depth, 118 for two-inch depth and 120 for the three-inch depth per 50 feet of row. When the soil was disturbed only on one side, two inches below the seed level, the average stand was 122 plants for both locations. Yield: The average yield for all of the unfertilized tests at College Station, where the soil was disturbed to the sides of the seed, was 162 pounds of lint per acre (Table 7). At Nacogdoches the yield was 128 pounds of lint per acr-e. The yield for the three tests at both locations was quite uniform, varying only 5 pounds of lint per acre at College Station and 8 pounds at Nacogdoches. The highest yield for each of the two locations was for the test where the soil was disturbed three inches below the seed level (Tables 7 and 8 and Fig. 10). SUMMARY AND CONCLUSIONS The experiments reported in this bulletin were conducted during the 5-year period (1936 to 1940 inclusive), at College ‘Station on Lufkin fine sandy loam and at Nacogdoches on Norfolk sandy loam soil. A 4-12-4 fertilizer was applied at the rate of 500 pounds per acre for all the fertilizer tests, and none was applied on the soil disturbance tests. Tests were planted when the fertilizer was placed one, two and three inches below and directly under the seed. Other tests were planted when the fertilizer was placed two inches to each side and one, two and three inches below the seed level. One test was planted when all of the fertilizer was placed on one side, two inches to the side and two inches‘ below the seed level. For each fertilizer test planted an un- fertilized test was also planted. Both sets of tests received the same soil disturbance. The results show, that when the fertilizer was placed under the seed, th-ere was an increase in the percentage of emergence and total stand as the fertilizer was placed deeperiand farther below the seed. When fertilizer was placed one inch under and below the seed, ger- mination was both delayed and reduced more than when the fertilizer was placed two inches and three inches below the seed. When the fertilize-r was placed to the sides of the seed, the percentage of emergence and total number of seedlings emerging decreased as the fertilizer was placed deeper and farther below the seed level. Fertilizer placed to the sides of the seed appeared to have a stimulat- ing effect on the germination of cottonseed as more plants emerged on the fertilized tests than on the unfertilized tests and higher percentages of emergence were obtained for the side applications than for the under the seed applications. GERMINATION OF‘ COTTONSEED 29 The highest percentage of emergence and the best stand was obtained at both locations when the fertilizer was placed two inches to each side and one inch below the seed level. The results obtained when all of the fertilizer was placed on one side compared closely with the divided placement at the same depth. For the under-the-seed placement of fertilizer the yields increased as. the the fertilizer was placed deper. For the side of the seed placement of fertilizer the yields increased as the fertilizer was placed deeper at Nacogdoches, but decreased slightly at College Station. The results show that when the soil is disturbed under the seed and cottonseed are planted in the loose soil, germination and the total num- ber of seedlings emerging is reduced. The effect increases as the depth of the disturbed soil increases‘. Disturbing the soil to the sides of the seed but not at the point where seed were placed in the soil did not appear to affect germination as the total emergence was very uniform for the different depths. At College Station the highest yield was obtained when the fertilizer was placed two inches to each side and one inch below the seed level, while at Nacogdoches the highest yield resulted when the fertilizer was placed two inches to each side and two inches below the seed level. Fertilizer applied in any manner significantly increased the yield at both locations. LITERATURE CITED 1. Collins, E. R, Mann, H. B., and Cumings G. A., Placement of Fertilizer for Cotton. North Carolina Agricultural Experiment Station Bulletin N0. 318, 1938. 2. Cumings, G. A., Mehring, A. L., and Sacks, W. H., Field and Laboratory Studies of Fertilizer Distributors for Cotton. Agricultural Engineering. Vol. 11, N0. 4, pages 149 to 160, 1930. 3. Cumings, G. A., Mehring, A. L., Senviss, G. H., and Sacks, W. H., Progress Report on Mechanical Application of Fertilizers to Cotton in South Carolina. U.S.D.A. Circular No. 192, 1931. 4. Smith. H. P., Morris, H. F., and Byrom. M. H., Machine Placement of Fer- tilizer for Cotton. Texas Agricultural Experiment Station Bulletin No. 548, 1937.