6 The Bulletin. 



4. The averao-e results show that lime, whether used alone or in 

 combination with nitrogen, phosphoric acid and potash, was at a 

 loss. On the two plats which had been continuously in corn and cot- 

 ton the losses were large from the application of lime, whether ap- 

 plied alone or in connection with the other three fertili/.er con- 

 stituents. These results cover seven years. On land which had 

 been in peas after grain four previous years there were good returns 

 in yields and profits from the use of lime alone and in combination 

 with nitrogen, phosphoric acid and potash. The results on the pea 

 land were for only one year. 



On the w^hole, the indications are that this soil does not need lime 

 for corn when cotton, corn, small grain and similar crops have been 

 grown continuously on it, but that it is benefited by lime when peas, 

 clover and similar crops have been grown, adding vegetable matter to 

 the soil. 



5. The amount of nitrogen in the normal fertilizer (300 ponnds 

 per acre) applied in the corn experiments was 3 per cent or 9 pounds 

 to the acre. This amount was varied so as to give 4.|, 9, 18, and 

 27 pounds of nitrogen per acre. The results emphasize the import- 

 ance of nitrogen for the production of corn on this soil when applied 

 in connection with a good amount of phosphoric acid and some 

 potash, the larger the amount of nitrogen the greater was the yield, 

 though the largest profit was obtained from twice the normal quan- 

 tity of nitrogen, or 18 pounds per acre. Eighteen pounds of nitrogen 

 would be supplied by 138.4 pound's of 13 per cent dried blood. The 

 average yield of corn during seven years on the plats receiving twice 

 the normal quantity of nitrogen and the normal quantities of phos- 

 phoric acid and potash (Ng P K) was 39.8 bushels per acre and the 

 average increase over unfertilized plats 24.2 bushels. This fertilizer 

 application cost $5.44 per acre, making the cost of fertilizer per 

 bushel of increase in corn 22.4 cents. 



6. The amount of potash in the normal fertilizer (300 pounds per 

 acre) used was 1| per cent, or 4i pounds per acre. This amount was 

 varied so as to apply 2.2, 4^, 9 and l^ pounds per acre respectively. 

 The results are quite uniform in showing that the larger quantities 

 were not as profitable as the normal amounts, li per cent in the 

 fertilizer mixture, or 4^ pounds per acre; 2.2 pounds, or the 

 smallest quantity of potash used, did not give as good results as 4^ 

 pounds, indicating that 4^ pounds of potash per acre, or H per cent 

 in the fertilizer mixture, is about the right amount for corn produc- 

 tion on this soil ; 4^ pounds of potash would be supplied by 22| 

 pounds of 20 per cent manure salt, 



7. The amount of phosphoric acid in the normal fertilizer (300 

 pounds per acre) used was 7 per cent or 21 pounds of phosphoric 

 acid per acre. This quantity was varied so as to apply 10^, 21, 42, 



