630 EXPERIMENT STATION RECORD. 



The main increased yields and profits came from the use of nitrogen and 

 potash. With phosphoric acid and potash the yield was slightly greater than 

 with nitrogen and phosphoric acid, but not nearly so great as with nitrogen 

 and potash. Nitrogen added to phosphoric acid and potash, making a complete 

 fertilizer, apparently increased the yield and gave an additional profit. The 

 application of lime alone was in general accompanied with some profit. 



Tests of the effect on the yield of cotton of varying quantities of nitrogen, 

 leaving the phosphoric acid and potash constant, indicated that nitrogen is one 

 of the controlling constituents, if not the most important one, for crop pro- 

 duction on this soil. Corresponding tests of the effect of varying the quantities 

 of phosphoric acid and potash showed no very marked effect on the yield of 

 cotton, and indicated that their application is not accompanied with much 

 profit. Tests of the comparative value of dried blood and nitrate of soda as 

 sources of nitrogen for cotton showed them to be about equally satisfactory. 



Experiments on the effect of different methods and time of application of 

 fertilizer showed that it made very little difference whether all the fertilizer 

 was applied in the drill before planting or whether one half was put in the 

 drill before planting and the remainder applied as a side dressing about July 1, 

 according to season. 



Information regarding varieties, culture, and fertilization of cotton on these 

 soils is appende<l. 



Fertilizer experiments with cotton on Piedmont Cecil sandy loam soil, and 

 varieties, culture, and fertilization of cotton on Piedmont Cecil sandy loam 

 and red clay soils, C. B. Williams. B. W. Kilgoke, and A. R. Russell (NortJi 

 Carolina Sta. Bui. 227 (191Jt), pp. 5-52).— Part 1 of this bulletin gives results 

 of a study to determine the proper fertilization for cotton on Piedmont Cecil 

 sandy loam and similar soils. " The use of a mixture carrying normal amounts 

 of phosphoric acid and nitrogen gave an average increased yield of seed cotton 

 per acre of 43 per cent over the yield secured, on the same character of land 

 without fertilization. The net profit over cost of fertilizer of this combination 

 was $15.14 per acre. Where a normal amount of potash was used with the 

 phosphoric acid in place of the nitrogen there was an average increase in yield 

 of 46 per cent of seed cotton and an average profit over cost of fertilizer used 

 of $19.17 per r.crc." 



The use of a fertilizer mixture carrying normal amounts of nitrogen and 

 potash was far less effective and profitable, the average net profit per acre being 

 only $4.84 per acre. Nitrogen, phosphoric acid, and potash combined in a com- 

 plete fertilizer yielded on an average only slightly more than when nitrogen 

 was left out of the mixture. 



Lime alone was used at a very small profit, while in a complete fertilizer it 

 has shown up on an average to a slightly better advantage. " Slightly the 

 largest profit per acre was secured by applying all the nitrogen along with the 

 phosphoric acid and potash before planting, having four-fifths of it derived 

 from dried blood and one-fifth from nitrate of soda. . . . The most profitable 

 method, everything considered, of applying the fertilizer mixture, the re- 

 sults would seem to indicate, would be in the drill at planting time at the 

 ordinary depth. . . . For the conditions prevailing and the length of time 

 covered by the experiments comparing the relative value of acid phosphate, 

 basic slag, and finely ground phosphate rock, the former material was found 

 to be decidedly the most efficient and profitable carrier of phosphoric acid for 

 cotton." 



Part 2 gives suggestions to growers of cotton on Piedmont sandy loam and 

 red clay soils as to varieties, culture, and fertilization. 



