17 
Effect of Nitrogen, Phosphoric Acid, Potash, and Lime Alone 
and in Combination With Each Other on Corn Yields. 
The experiments, the results of which are presented in Table 9, 
were planned to show the effect on the yield of corn of nitrogen (N), 
phosphoric acid (P), and potash (K) when applied singly, when two 
of the constituents were applied together, as nitrogen and phosphoric 
acid (N P), nitrogen and potash (N K), and phosphoric acid and 
potash (P K), and when all three of these fertilizer constituents 
were applied to make a complete fertilizer (N P K) ; also to test the 
effect of lime (L) when used alone and when used in connection with 
a complete fertilizer (N 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 yields aver¬ 
age increases over the unfertilized (O) plats, which represent the 
effect of the fertilizer applications, the value of the increase, the 
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 3 2 , 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 
from the use of nitrogen, the average results for the plats in the 
three fields being an actual loss in both yield and value of product 
from the application of nitrogen alone. The average annual loss 
was $1.95 per acre on basis of corn and stover and $1.66 per acre 
on basis of corn alone. 
Phosphoric Acid, P (Plats 4 2 , 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 6.5 bushels of corn per acre, for two years in Field A 5 bushels, 
and for one year in Field C 7.4 bushels, or an average for seven 
years in all three fields of 6.2 bushels, worth at 70 cents per bushel 
$3.29 per acre for corn alone, or $4.05 for increased yield of com 
and stover over cost of fertilizer. 
Potash, K (Plats 6 2 , 3 and 3). Except the first year in Field 
B, there was less corn produced on the plats receiving potash alone 
than on the unfertilized plats, the average for the seven years being 
slightly less where potash was used than where no fertilizer was 
applied, and the potash was used at a loss. 
Nitrogen and Phosphoric Acid N P (Plats 7 2 , 5 and 4). From 
nitrogen and phosphoric acid increased yields over the unfertilized 
plats were obtained in all seven years in the three fields, the aver¬ 
age annual increase for the four years in Field B being 17.5 bushels 
of corn per acre; for two years in Field A 22.4 bushels of corn per 
acre, and for one year in Field C 16.3 bushels, or an average annual 
* 
