24 The Bulletin. 



EFFECT OF NITROGEN, PHOSPHORIC ACID, POTASH, AND LIME 



ALONE AND IN COMBINATION WITH EACH OTHER 



ON CORN YIELDS. 



The experiments, tlie results of wliich are presented in Table I, 

 were planned to show the ell'cct on the yield of eorn of nitrogen (X), 

 phosphoric acid (P), and potash (K) when applied sinal.v, when two 

 of the constitnents were applied together, as nitrogen and phosphoric 

 acid (N P), nitrogen and potash (N K), and ])hos]ihoric acid and 

 potash (PK), and when all three of these fertilizer constitnents 

 were applied to make a complete fertilizer (N P K) ; also to test the 

 effect of lime (L) when nsed alone and when used in connection with 

 a complete fertilizer (iST P K L). 



The results are shown in yields of bushels of shelled corn and 

 pounds of stover per acre for the several years, average yiekls, aver- 

 age increases over the unfertilized (O) plats, which rejjresent the 

 effect of the fertilizer applications, the value of the increase, th.e 

 cost of the fertilizer, and the value of the increased yield of corn and 

 stover and of corn alone over cost of fertilizer. The value of the in- 

 creased yield of corn and stover and of corn alone represent the 

 profit from the several fertilizer applications after paying for the 

 fertilizer itself. 



In these experiments the corn was cut, shocked and shredded, the 

 stover being all of the plant except the corn on the cob. 



Nitrogen, N (Plats ?r, 1 and 1). During six years the average 

 results on the plats in Fields A and B show decreased yields and in 

 the value of product, while for one year in Field C there was a gain 

 fi-om the use of nitrogen, the average results for the plats in the 

 three fields being an actual loss in both yield and value of pi'oduct 

 from the application of nitrogen alone. The average annual loss 

 was $1.95 per acre on basis of corn and stpvcr and $1.GG per acre 

 on basis of corn alone. 



Pliosplioric Acid, P (Plats 4", 2 and 2). Phosphoric acid alone 

 produced increased yields in all of the seven years on the plats in 

 the three fields, the average increase for four years in Field B 

 being G.5 bushels of corn per acre, for two years in Field A 5 bushels, 

 and for one vear in Field C 7.4 bushels, or an average for seven 

 years in all three fields of 0.2 bushels, worth at 70 cents per bushel 

 $3.29 per acre for corn alone, or $4.05 for increased yield of corn 

 and stover over cost of fei'tilizer. 



Potash, K (Plats G', 8 and 3). Except the first year in Field 

 B, there was less corn produced on the ]dats receiving jiotash ahme 

 than on the unfertilized plats, the average for the seven years being 

 slightly less wdicre potash was used than where no fertilizer was 

 applied, and the potash was used at a loss. 



