88 The Bulletin 



(19.1 bushels per acre). This indicates that nitrogen is more important 

 on this soil than potash for corn production. 



Lime, L (Plats 14-, 4* and 7-). Lime was applied at the rate of 500 

 pounds rock or 1,000 pounds slaked lime per acre every fourth year. 

 On the plat in Field A there was a loss of $13.29 annually per acre, and 

 on the plat in Field C in one year's test a profit of $9.56, the average for 

 the seven years being a loss of $2.02 per acre. On the plat in Field 

 B during four years there was a profit of 25 cents per acre from the use 

 of lime. The plat in Field C, where there was a profit from the use of 

 lime, had been in peas after grain during four previous years. 



Complete Fertilizer with Lime, N P K L (Plats 152, q4 ^nd 92). 

 When lime was used in combination with the three fertilizer constitu- 

 ents there was less corn produced on all the plats in Fields A and B 

 than where the three fertilizer constituents were used without lime, but 

 on the plat in Field C, which had previously been in peas and grain for 

 four years, there was a decided gain from the use of lime. As an aver- 

 age of all the tests there was a smaller increased yield of corn and profit 

 v/here lime was used than where it was not. 



As an average of all the results, the experiments show: 



(1) That nitrogen alone on this soil for the production of corn was 

 used at a loss ; 



(2) That potash alone had practically no effect on the yield and was 

 used at a loss; 



(3) That nitrogen and potash combined increased the yield very 

 slightly but at a loss; 



(4) That lime alone, except where peas had been previously grown, 

 was used at a loss ; 



(5) That phosphoric acid alone gave increased yields and profits in 

 all cases, showing that it is the most important constituent for corn 

 production on this soil; 



(6) That nitrogen combined with phosphoric acid added decidedly 

 to the increased yields and profits, the average annual increase for 

 phosphoric acid alone being 6.2 bushels and for nitrogen and phosphoric 

 acid 18.8 bushels per acre; 



(7) That potash added to phosphoric acid increased the yields decid- 

 edly over phosphoric acid alone, the average annual increase for phos- 

 phoric acid alone being 6.2 bushels per acre, and for phosphoric acid 

 and potash 16.5 bushels; 



(8) That potash added to nitrogen and phosphoric acid resulted in 

 a small increase in yield and without profit; and 



(9) That the yields from the addition of lime to nitrogen, phos- 

 phoric acid and potash were smallei' than from the three fertilizer con- 

 stituents combined. 



The most important constituent in producing increased yields and 

 profits on this soil was phosphoric acid. Nitrogen and potash singly or 

 combined, gave good returns when used with phosphoric acid, but were 

 of little or no value when used alone or with each other. Nitrogen 

 added more largely to the yields than did potash. 



Effect of Varying Quantities of Nitrogen. — The results of the por- 

 tion of the experiments devoted to a. study of the effect on the yield of 

 corn and stover of varving quantities of nitrogen, leaving the phos- 



