50 



The Bulletin 



The results of five years' tests of this field certainly show that nitro- 

 gen is decidedly in greatest need hy this soil. The returns per acre, 

 above that secured from the unfertilized plat, from the three crops of 

 corn and the two crops of cotton were more than twenty times as much 

 for nitrogen alone as for phosphoric acid alone, and more than six and 

 one-half times as much as for potash used alone. Nitrogen alone on an 

 average has given 39.4 bushels of corn and 1,426 pounds of stover, and 

 510 pounds of seed cotton increases per acre. Phosphoric acid used 

 alone has only averaged a gain of 0.5 bushels of corn and 53 pounds 

 of stOA^er, and 40 pounds of seed cotton, potash alone an average gain of 



Fig. II. Rye as a cover crop after cottou, sown during fall of 1911 on Charlotte Field 

 No. 2 and photographed the following spring just before breaking the land for corn. 

 Note the difference in growth of rj-e secured on the two plats (7 and 8) for turning 

 into the soil. 



0.9 bushels of corn and 126 pounds of stover, and 230 pounds of seed 

 cotton, and lime alone 3.7 bushels of corn and 140 pounds of stover, 

 and 230 pounds of seed cotton per acre. On an average of three years' 

 results Avith corn and tv'o Avith cotton, the average gain for nitrogen used 

 alone and in combinations has been 42.9 bushels of corn and 1,613 

 pounds of stover, and 528 pounds of seed cotton. 



For phosphoric acid a decrease of 0.3 bushels of corn and 3 pounds 

 of seed cotton and an increase of 20 pounds of stover; for potash an 

 increase of 5.0 bushels of corn and 470 pounds of stover, and 218 pounds 

 of seed cotton; and for lime a decrease of one bushel in the yield of 

 corn, but an increase of 104 pounds of corn stover, and 120 pounds of 

 seed cotton per acre. Phosphoric acid used with nitrogen or potash 

 alone seems to have had on an average a rather depressing effect upon 



