TEXAS AGRICULTURAL EXPERIMENT STATIONS. BULLETIN NO 101 January, 1908. Irish Potato Fertilizer Experiments A Postoffice, COLLEGE STATION, BRAZOS COUNTY, TEXAS. TEXAS AGRICULTURAL EXPERIMENT STATIONS OFFICERS. GOVERNING BOARD. (Board of Directors A. &. M. College.) K. K. LEGGETT, President . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Abi1ene T. D. ROWELL, Vice President . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . ..Jefferson A. HAIDUSEK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..LaGrange J. M. GREEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Yoakum WALTON PETEET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Da11as R. T. MILNER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Austin L. L. McINNIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Bryan W. B. SEBASTIAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..I7rec1:enridge STATION OFFICERS. H. H. HARRINGTON . . . . . . . . . .LL. D., President of the College and Director J. W. CARSON . . . . . . . . . . . . ..Assistant to Director and State Feed Inspector W. C. WELBORN . . . . . . . . . . . . . . . . . . . . . . . . ..Vice Director and Agriculturist M. FRANCIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Veterinarian E. J. KYLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Horticulturist JOHN C. BURNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..An1ma1 Husbandry R. L. BENNETT . . . . .; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Cotton Specialist O. M. BALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Botanist G. S. FRAPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Chemist C. E. SANBORN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..C0-Operative Entomologist N. C. HAMNER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Assistant Chemist E. C. CARLYLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Assistant Chemist L. McLENNAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Deputy Feed Inspector A. T. POTTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Deputy Feed Inspector J. H. RODGERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Deputy Feed Inspector H. E. HANNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Deputy Feed Inspector C. W. CRISLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Chief.C1erk W. L. BOYETT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Clerk Feed Control MISS PATTI McCLELLAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Stenographer W. E. BERRY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Stenographer STATE SUB-STATIONS. W. S. HOTCHKISS, Superintendent . . . . . . . . . . . . . '. . . . .Troupe, Smith County S; A. WASCHKA, Superintendent . . . . . . . . . . . . . . . . . . . ..Beeville, Bee County NOTE--The main station is located on the grounds of the Agricultural and Mechanical College, in Brazos County. The postoffice address is College, Station, Texas. Reports and bulletins are sent free UPOn application to the Director. m, ma?» i I I I Insh Potato Fertflizer Experiments W. S. Hotchkiss and E. J. Kyle. The fertilizer work with the Irish potato at Troupe was first planned in the fall of 1902. The results which were gotten upon harvesting the crop in the spring of 1903 were so opposed, especially in reference to pot- ash, to what had been obtained at anumber of stations in diflerent States, it was decided to get out a preliminary report. Bulletin No. 71 con- tains these results, a summary of which is, as follows: 1. The gray sandy, clay soil,with red subsoil at the Troupe Station re- sponded more profitably to an application, of acid phosphate than to any oth- er single fertilizer. 2. In a complete fertilizer, potash over 6 per cent was unprofitable, while unusually large percentages (8 per cent and 10 per cent) 0f phos- phoric acid greatly increased the yield. 3. Cotton seed meal applied only a few days before planting was too slowly available to prove a desirable fertilizer for early potatoes. The work recorded in the present bulletin is a continuation of that al- ready done, with a view to the further verification of the somewhat unex- pected results above given. Since 1903 this work has been continued each year, with the exception of 1905 when all the potatoes rotted in the ground, on account of the un- usually wet weather. l This bulletin, therefore, contains the results gotten from the crops of 1904, ’06, ’07, together with those of 1903. In 1904 the land used for the experiment was comparatively new, though two years earlier it had raised a crop of sorghum. The previous season it had “laid out” uncultivated. After being fiat-broken six inches deep with a turning plow the soil was thoroughly worked during January, and in February the rows were laid off with a middle burster three and a half feet apart, the fertilizer was applied along the rows by hand and then worked into the soil by running a five-tooth horse hoe along the rows. Home grown, second crop Triumph potatoes were planted Feb. 25th. They had been cut to two eye pieces about ten days earlier. A good stand was secured on all plats. . Before the plants were up the field was harrowed with a spike-tooth har- row, and subsequent cultivation was given every ten days with the five- tooth horse hoe cultivator. Notes on Appearance of Plats May 26th: Plat 1. Plants one-third larger and darker color than check. Plat 3. Plants one-third larger than check. “ 5. About same size as check. “ 7. Plants two-thirds larger and darker color than check. “ 9. “ one-half larger than check. “ 11. “ one-half larger than check. “ 13. “ but little larger than check. “ 15. “ two-thirds larger than check, darker color. “ 17. “ two-thirds larger than check, darker color. c?%ofi “ 19. “ 21. “ 23. “ 25. “ 27. “ 29. “ 31. “ 33. “ 35. “ 37. “ 39. “ 41. On June 24th, the tops were mature and the crop was harvested. two-thirds larger than check, darker color. one-half larger than check. three-fourths larger than check. three-fourths larger than check. two-thirds larger than check. one-third larger than check. two-thirds larger than check. two-thirds larger than check. tw0_thirds larger than check. three-fourths larger than check. nearly twice larger than check. slightly larger than check. (4) Harvest Record-Irish Potato Fertilizers at Troupe. Yield Plat Percent of Pounds Marketable Grain No Fertilizer Used Plant Used Bushels Culls. market- Food Per Acre. able. 1 Nitrate0fSoda....16 N....94 . . . . . ..60.. ......91-3bu 13bu 2 ‘Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..47 . . . . . . . ..6 bu . . . . 3 Acid Phosphate...14P.....285..... 5O 1-3..... 62-3 bu 5bu. 4 Check . . . . . . . . . . . . . . . . . . . . . . . . . . . ..441-3.....6bu . . . . . . . . . . . .. 5 Sulphate of Potash. 50 K 80.. 40 1-3. .. .. 5 1-3 bu _- 7 bu, 6 Check . . . . . . . . . . . . . . . . . . . . . . . . . . . ..50 3-4.....42-3bu . . . . . . . . .. 7 N. 7 Cottonseed Meal ..3P.».....210..... 73 1-3.. 6 bu . . . . ..21 bu 1 % K .. i 8 cheCk . . . . . . . . . . . . . . . . . . . . . . . . . . . ..54 . . . . . . . ..4bu... . . . . .. 9 Nitrate of Soda. . .. 4 N. . 94 . . . . . .. 82 1-3 . . . . .. 11 1-3 bu 26 bu Acid Phosphate . .. 10.5 P 285 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10 Check . . . . . .. .. . . . . . . . . .. 591-3 . . . . ..51-3bu . . . . . . . .. 11 Nitrate of Soda 8.6N 94 . . . . . .. 82 . . . . . . . . .. 4 1-3 bu .30 bu... . Sulphate of Potash. 23 K 80 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12 Check . . . . . . . . . . . . . . . . . . _ . . . . . . . .. 46 . . . . . . . . .. 7 2-3 bu . . . . . . .. 13 AcidPhosphate...I1P.....285 . . . . ..60 2-3 . . . . ..4bu.....14bu Sulphate of Potash. 11 K.. 80.. . . . . . . . . . . . . . . . . . . . . .. .. 14 Check . . . . . . . . . . . . . . . . . . . . . . . . .. 46 . . . . . . .. 7 2-3 bu . 15 Nitrate0fSoda....3.3 N. .94 . . . . . . . . . . . . . . . . . . .. Acid Phosphate...8.6P.. .285 ....74 2-3 . . . . ..6 bu .....28 bu Sulphate 0f Potash. 8.2K.. 80. . . . . . . . . . . .. . . . . . . . . , . . . .. 16 Check . . . . . . . . . . . . . . . . . . . . . . . . . . .. 47 . . . . . . . .. 10 1-3 bu . . . . . . .. 17 Nitrate of Soda. - 3.8N.. .94.. . . . . . . . . . . . . . . . . . . . .. . Acid Phosphate 7.7 P.. .215 90 . . . . . . . . .. 63-4 bu 39 bu.. Sulphate ot Potash. 10.2 K. 80 . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .... 18 Check . . . . . . . . . . . . . . ..59.. 8lz3bu . . . . . . . .. 19 Nitrate of Soda 3.4N.. 94 . . . . . . . . . . . . . . . . . .. Acid Phosphate... 8.8 P.. . 285.... 74 2-3..... 62-3 bu .29 bu Sulphate of Potash. 6.5 K.. . 59 . . . . . . . . . . . . . . . . . . . . .. 20 Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~30 . . . . . . . . ..6bu . . . . .. 21 NitrateofSoda....3N.... 94 . . . . . . . . . . . . . . . . . . . . . . . .. Acid Phosphate 9.5 P. . .. 331 . . . . .. 51 . . . . . . . .. 5 2-3 bu .19 bu Sulphate of Potash. 6 59 . . . . . . . . . . . . .. .. .. . . . . . . . .. 22 Check.... .. . . . . . . . . . . . . . . . ..331-3 . . . . ..8 bu . . . . . . . . . . .. 23 Nitrate of Soda.... 4.6 N... 143 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Acid Phosphate...8.2 P....285. ....'70 2-3... ..91—3 bu .25 bu SulphateofPotash.6K.... 59 . . . . . .. .. . . . . . . .. 24 Check... . . . . . . . . . . . . .. 56 . . . . . . . . ..32-3bu . . . . . . . . .. 25 NitrateofSoda... 4.2 N...142 . . . . . . . . . . . . . . . . AcidPhosphate...8.7 P....331.. ...78 3-4 . . . . ..4 bu . . . . ..23 bu Sulphate of Potash. 5.5 K. . 59 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 26 Check . . . . . . . . . . . . . . . . . . . .. ... 54 . . . . . . . . .. 6 2-3 bu . . . . . . . . .. 27 NitrateofSoda....4N.....94. .. . . . . . . . .- Acid Phosphate . .. 8.1 P. 215. 87 . . . . . . . .. 5 bu . . . . .. 36 bu SulphateofPotash.8K.....59 . . . . . . . . . . . . . . . . . . . .. 28 Check . . . . . . . . . . . . . . .. 481-3 . . . . ..5 bu . . . . . . . . . . . . .. 29 Nitrate0fSoda....2.7 N...94. . . . . . . . . . . . . . . .. Acid Phosphate I0.1 P. .. 400 . . . . .. 40 2-3 . . . . .. 4 bu . . . . .. — 14 bu. Sulphate of Potash 5.3 K.. 59 . . . . . . . . . . . . .. .. . . . . . . . . . . .. 30 Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 60 2-3. 8 bu . . . . . . . . . . . . . .. 31 Cottonseed Meal .. 3 250 . - - - - - - - - - - - - - - - - - - -- Acid Phosphate...8P . . . . ..285.... 62.... .....3l-3bu 11 bu. Sulphate of Potash. 5.6 K. .59 . . . . . .. . . . . . . . . . . . . . . . . .. 32 Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42 1-3 . . . . .. 4 2-3 bu 33 CottonseedMeal...lv2_7 N. . . . . .. Acid Phosphate .. 8.4 P 331 . . . . .. 63 1-3 . . . . .. 6 bu. 18 bu Sulphate of Potash. 5 K. .. 59 . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. “Yield - Plat Percent of Pounds Maretable Grain No. Fertilizer Used Plant Used. Pounds Culls. market- Food . Per Acre. a able. 34 Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 48 2-3 . . . . .. 5 1-3 . . . . . . . . . . . . . .. Cottonseed Meal .. 3 N. . . . . 250 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 35“ Acid Phosphate... 7.77 P 257.. . .. 73 . . . . . . . . 7 . . . . . . . .. 24 bu Sulphate of Potash. 6 K. . . . . 55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Check.. . . . . . . ..- . . . . . . . . . . . . . ..501-3.....5 . . . . . . . . . . . . . . . . .. Cotton Seed Meal.. 3 300 . . . . . . . . . . . . . . . . . . . . . . . . .. 37 Acid Phosphate... 5.2 P.. . . 200 . . . . .. 95 . . . . . . . .. 6 2-3 . . . . .. 43 bu Kainit . . . . . . . . . . ..4K.....200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 38 Check.... . . . . . . . . . . . . . . . . . . . . . . ..54 2-3..... 32-3 . . . . . . . . . . . . . .. 39 Manure . . . . . . .- . . 20 wag lds . . . . . . . . . 91 . . . . . . . . .. 6 . . . . . . .. 41 bu. 40 Check . . . . . . . . . . . . . . . . . ..46 2-3 . . . . ..62-3 . . . . . . . . . . . . .. 41 Ashes........y... . . . . . . ..80bu 652-3.. 8 19bu 42 Check . . . . . . . . . . 46 . . . . . . . . ..5 By comparing the yield of any fertilized plat with the average yield of the two adjacent check plats, it will be seen that cotton seed meal, when used alone, gave a greater increase in yield than any other single fertilizer. Plat 7 received an application of 210 lbs. of cotton seed meal, and its in- crease in yield over its check plats was nearly equal to the average increase of the 12 plats that received complete mixtures varying in weight from 390 lbs. to 700 lbs. and averaging over 500 lbs. each; and gave a greater increase in yield than the average of the 15 plats upon which potash was used. Pot- ash when used alone gave very poor results as far as increase in yield was concerned. Nitrate of soda and acid phosphate when used together gave good results. Plat 9. Plat 37 made the greatest increase over its check plats. This plat re- ceived more nitrogen and less potash than any other plat having a complete mixture. Barn lot manure made a good yield, but 25 per cent were scabby and unfit for market. EXPERIMENTS IN 1906. In 1906 duplicate plantings were made which will be referred to as Field A and B. Field A, had raised a crop of Irish potatoes in 1903, and a crop of cas- tor beans in 1904. During 1905 the land was not cultivated. In November 1905 the field. was fiat broken with a turning plow running six inches deep. It was thoroughly harrowed with a disc in February and again in March. Field B, had “laid out" in 1903. A crop of corn was grown on it in 1904 and in 1905 a crop of cowpeas. The pea-vines were partly green when plowed under in October. Plowing was at the same depth as in Field A. In No- vember the land was harrowed with a disc and this culture was repeated in February and again in March. Field A, was planted March 13th; Field B, the following day. The method of distributing fertilizer and mixing it with the soil, and the subsequent cultivation, was similar to the respective operations of previous years. Field A.——Notes on Growth, June 4th: (6) l Plat Plat 1. Plat Plat Plat Plat Plat Plat Plat Plat Plat Plat 12. 10. 11. Made vigorous growth, well matured, very few at this date, leaves half ‘dead. Vines more vigorous, about two or three inches taller and prob- ably one-fourth more green leaves, making them three or four days later than. Plat 1, in ripeness. a » ‘ Vigor about same as Plat 1, but lacks a day or two in ripeness though a marked contrast exists between-the rows, the west row being the greenest. ' Three-fourths stand. Growth about thesame as Plat 1, but a little later. About same as Plat 1. Three-fourths stand. Growth superior to above plats; about the same as Plat 2. Slightly smaller than Plat 6, maturity about same. Three-fourths stand. Growth not equal to Plat 6, but averages a little better than Plat 7. Growth one-fourth less and maturity three or four days ahead of 6, dark green leaves maturity 7, or 8. Three-quarter stand. Growth strong, about same as plat 6; a very little earlier. Not quite as early as Plat 9. Very strong growth; color darker than other plats; three days later than Plat 9. Growth about same as checkplat (9), and about same degree of maturity. This plat can hardly be used in comparison as about one-fourth of it is on red clay. Field B.—Notes on Growth June 4th: Plat 1. Plat 2. Plat 3. Plat 4. Plat 5. Pla.t 6. Plat 7. Plat 8. Plat 9. Plat 10. Plat 11. Plat 12. Growth fairly vigorous; greenish yellow, no dark green leaves. One-fourth more vigorous than Plat 1. Half week later. Growth one-fourth better than Plat 2, and one-half better than Plat 1. Growth one-half better than Plat 1, one week later. About same as Pat 1, little better stand. Very vigorous, three-fourths larger than Plat 5, one week later. Probably same as 3 and 4. Three-fourths stand, growth nearly equal to Plat 6, maturity about the same. About a week later than Plat 5, not quite so good a growth as Plat 7. Growth, color and ripeness compare well with 1-5. Growth slightly superior to 7-8-9. Maturity about same as 6:7. Growth about same as plat 10. Maturity two or three days later. One-third larger than check plat; maturity half week later. (7) 00mm wofiweomm MMWHAHHNMWM. $00. 0.0m." Z0. \ 002252: G000. 0.3 00:" 05:0 0000 000:“? 0m 0.02259 0E >20 @0000 70018300 055% 0Q >2» MJMFU > 02w Q00: O03 70012000000 MJMPU w 002m Q3: O<$ 0062» 0052921.... 00:0: $3 Z20. >000 0080008. . . 002F111 0020: m¢00 0S2: "<1 O\ Ola-PU) N) l-i >000 0:80:08. . . @0158 0» 00960. 0O 0020: @020 Z20. @5000?” 0m 003.00. 0 000000.... 0030: @000 702.0. ~0 >000 0080008 . . m=€5$ a 00:50. 0030: @000 22:. >000 00000.58 . . m=€5$ 00 00360. 00:0: m2.» Z21. >20 00800081. 900058 0m 00350. : Q co .m:_0:m8 0* 00350. . a ¢ >20 0030058 . . . .. U'\OOI\JU'\OOX\JU1OCI\J- 00 00 §m ~@ ?‘~U . -|¢ .8? .%;:::. M001... 02.11.... 0001...... %9:::. %;:::. .w00........ m00......... 0001...... 001...... 0001...... 0001...... 000.11.... ~00. 0001...... 00.... 000:1. 0»@@¢H m0; . -¢-¢..-¢- 00 0-0-1.. 0m T0. 0» 0-0.“... .001. 0 00 0-0.2.. :1. wmw :2. a... mun ¢--. .0» 3... .3 0-0.... |-.¢--- .00 0-0 -.--¢ 00¢»- ..¢.-¢-¢< 000;- -.-.-¢¢.. :0; .8 .»ww; 00¢» 0.. . 00 0-0. 000“ 0-0. ~0 .001.-. W%H @¢~=;»;@; a>H-.0@»;H 0»H»@»>». mwH~HHH.~ 00»HH.... Z; 223N005 W; 009000010 02.0w W; 0035:. Z00.m.||...0:m 010m 0% KEEN? aw 0: 0000. 2mm mm 00:03? 0020: a 00350. 000.00 02 3:. mm¢0 7>@»_0 $0.00 03 3E >20 0:30:03. 000.00 0Q ~05 @515»... By adding the results of the duplicate plats together, it will be seen that potash as a single fertilizer gave considerably the smallest yield. Acid . phosphate did slightly better than cotton seed meal, both doing well. The largest yield was made with a complete fertilizer containing 1100 lbs. The next largest was made by the combination of cotton seed meal and acid phosphate. The fact that this mixture out yielded all complete fer- ' tilizers with the exception of one,again goes to prove that nitrogen and phosphoric acid are t'wo elements ofplant food most needed by soils simi- lar to that of our Sub-station at Troupe. EXPERIMENTS IN 1907. The land used in this experiment was old, cotton being grown npon it ln 1904, tomatoes in 1905, and cotton again in 1906. The soil was flat-broken during December and thoroughly harrowed during February. On March 6th, rows were laid off with a middle-burster, the fertilizer distributed and thorougly worked in with a bull-tongue. On the same date home-grown second crop Triumph were planted. The seed were banked up during the winter and were well sprouted‘ when uncovered for planting. . NOTES. All plats were up to a perfect stand March 25th. Notes on Irish Potatoes, May 27th, '07. i Plat 1. Moderate growth. Vines light green, nearly mature. Plat 2. Strong, vigorous growth, dark green foliage. This plat was plant- ed directly over a “back-furrow” and that seems to have given it some advantage throughout the season. Plat 3. Strong growth but not as healthy appearing as Plat 2. Plat 4. Growth and general appearance about same as check plat. Plat 5. No noticeable difference from Plat 1-4. Plat 6. Growth strong and vigorous. Foliage dark green. Three-fourths larger than check plats. Plat 7. Growth smaller and foilage lighter colored than on Plat 6. Plat 8. Compares favorably with Plat 2. Plat _9. Only moderate growth. Plat 10. Strong, vigorous growth. Foliage dark and healthy. Plat 11. Very strong, one-third larger than Plat 10. Plat 12. Healthy, about the same as Plat 10. Plat 13. About the same as other check plants. Plat 14. Very strong, vigorous growth. Foliage dark and healthy. Plat 15. About same as Plat 10. Plat 16. No noticeable difierence from Plat 14. (9) IRISH POTATO EXPERIMENT, 1907...HARVEST RECORD. Percent of Yield Plant Pounds of Marketable Gal" Plat Fertilizer Used Food Fertilizer Bushels Culls Mgkeeb Per Acre 1 Check . . . . . . . . . . . . ..46bu . . . . . ..13.3 bu.... 2 Cotton Seed Meal 7. N.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . ..3.P... 200. . . . . . . . . ..1.5 K.. . . . . . . . ..94.6 bu.....12.3 bu . . . . ... . 3 Acid Phosphate. 14. P. .. 300 . . . . .. 80 bu . . . . . .. 9 bu.. 4L bu 4 Sulphate of Potash 50. K 5O . . . . .. 40 bu . . . . .. 8.6 bu . . . . . .. 19 bu. 5 Check . . . . . . .. . . . . . . . . . . . . . . . . ..21.6bu.....5bu. . . . . . . . . . . . . .. . . . . . 6 Cotton Seed Meal. 9.6 P... 200 . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . .. Acid Phosphate .. .6 300 . . . . .. 73.3 bu..... 12 bu 51 bu 7 Acid Phosphate... 12. P... 300 . . . . . . . . . . . . . . .. . . Sulphate of Potash. 7.4 K.. 50 . . . . .. 65.6 bu..... 10 bu . . . . . .. 37 bu 8 Cotton Seed Meal. 2.4 P. .. 200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . .. Sulphate of Potash. 5.6 N.. 50..... 88.3 bu. 14.3 bu . . . . .. 53 bu .. . . . . . . . . .. 11. K . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9 Check . . . . . . . . .. . . . . . . . . . . . . . . .. 35 bu . . . . .. 13.6 bu 10 CottonSeedMeal.2.5 N...200..... .. . . . . .. Acid Phosphate... 8.7 P. .. 300. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Sulphate of Potash. 5. K. .. 50 110 bu . . . . .. 13.3 bu.. 75 bu 11 Cotton Seed Meal.2.5.... 400 . . . . .. .. . . . . . .. Acid Ph0sphate...8.7P.... 600 . . . . . . . . . . . . . . . .. . . . . .. Sulphate of Potash. 5. K. . .. 100 126.3 bu 2 bu . . . . . . .. 86 bu 12 Cotton Seed Meal. 2.5 N... I00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Acid Phosphate... 8.7P 150 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Sulphate of Potash. 5. K. .. 25 . . . . .. 97 bu . . . . . .. 10.3 bu 51 bu. 13 Check . . . . . . . . . . .....46.6 bu.....6.6bu 14 NitrateofSoda. .3. N... 94 . . . . . . . . . . . . . . . . .. Acid Phosphate... 8. P.... 285 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Sulphate of Potash. 6. K... 60 . . . . .. 115.6 bu 8 bu. . . . . .. 69 bu 15 Cotton Seed Meal 3.8 N... 300 . . . . .. . . . . . .. . . . . . . . . . . . . . . . . .. Acid Phosphate... 6.7 P. .. 200 . . . . . . . . . . . . . . .. . . . . . . .. Sulphate of Potash. 5.3 K.. 50 86.3 bu..... 10 bu . . . . . .. 40 bu 16 Nitrate of Soda.... 3. N.. 94 . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. Acid Phosphate...10.P.. .331.. . . . . . . . . . .. Sulphate of Potash 6. K.. 50 . . . . .. 116.6 bu.... 6.3 bu . . . . . .. 72 bu Cotton seed meal when used alone gave better results than any other single fertilizer (See plat 2). Potash again gave the smallest yield, (See Plat 4). It will be seen by referring to the notes,that Plat 2 was directly over a. back-furrow but it is hardly probable that this effected it to any great ex- tent. Acid phosphate alone gave good results,‘ (See Plat 3) Acid phosphate and cotton seed meal combined, although giving an increase of yield, did not give as satisfactory results as usual, (See Plat 6). This may have been The fact that its check plat (5) adjoining it gave such. a decidedly smaller yield than any other check plat and that it yielded less than either acid phosphate or cotton seed meal alone would lead to this due to soil variation. suspicion. While potash apparently tended to increase the yield where a complete fertilizer was used, its failure to give beneficial results when used alone (Plat 4) 0r in combination with acid phosphate (Plat 7) or with cotton seed meal (Plat 8) does not justify the conclusion. (10) SUMMARY The total results show that nitrogen gave very beneficial results through- out the four years, whether used in the form of cotton seed meal or nitrate of soda. When used in a complete fertilizer the results show that there was very little difference between the nitrate of soda and cotton seed meal. ' The average yield of the nitrogen plats as against the check plats shows an increase of 21 bushels in favor of the nitrogen. Acid phosphate alone gave good results three out of four years and in- crease enough to be slightly profitable the other year. The average in- crease in yield in trial over the average yield of the check plat exceeds 23 bushels. Nitrogen and phosphoric acid combined averaged as much in the four years as the varying amounts of nitrogen and phosphoric acid com- bined with potash. Averaging the nitrogen plats as against nitrogen-phos- phoric acid plats, the latter exceed the former in average yield for four years by about 20 bushels. Comparing the acid phosphate plats with the acid phosphate-potash plats shows that the latter out-yielded the former by an average of only 6-10 of a bushel for the four years. Averaging the check plats as against the potash plats, the latter out- yielded the former by an average of four bushels in the four years-—-about enough to pay for the potash. During the four years, potash gave comparatively negative results. The total results would hardly justify its use so far as yield is concerned. The fact has been demonstrated, however, that potash has some influence on the keeping and carrying quality of fruits and vegetables; and as the potato is grown almost exclusively for early shipping, the use of a small amount of potash is probably advisable. Since it has been demonstrated that nitrogen is one of the elements most lacking in the soil, it i_s very advisable, when possible, to turn under a crop of cowpeas on the land in advance of planting the potato crop. The potatoes are harvested so early in the season there is plenty of time to grow a good crop of peas for turning under during the fall. Judging from the beneficial results obtained from both sources of nitrogen, and from the fact that it takes some time for cotton seed meal y: to become available, nitrate of soda being available at once, it would seem that the best possible results would be to use some of both elements. If this is done, the fertilizer could be applied just before planting, instead of ten days in advance, as is now recommended for cotton seed meal. The nitrate of soda would supply the nitrogen at the beginning of growth, and, about the time it was giving out, the cotton seed meal would become available and carry the crop on to maturity. While we have not yet tried this mixture, the indications are that it will prove most satisfactory. The ‘following formula is therefore recommended for all sandy East Texas soils: 1,000 lbs. Acid phosphate, 14per cent. 700 lbs. Cotton seed meal. 200 lbs. Kainit. 100 lbs. Nitrate of soda. This formula will give 8 per cent acid phosphate, 3.20 per cent nitrogen, 1.7 per cent potash. In case no nitrate of soda or potash is available, the .» following is suggested: 1,200 lbs. acid phosphate; 800 lbs. cotton seed meal. From 400-600 lbs. of such formula should be used per acre. ' (11)