FIELD EXPERIMENTS WITH FERTILIZERS. 203. 
SUMMARY AND GENERAL DEDUCTIONS. 
Lhe special nitrogen experiments here reported were made with 
corn, cow peas, and soy beans. The purpose of the experiments 
ts twofold: First, to study the effects upon the yields of the crops 
when different kinds and quantities of nitrogenous fertilizers are 
used in addition to uniform quantities of mineral fertilizers, and 
second, to study the effect of the nitrogen in the fertilizers upon the 
proportion and amount of protein in the crops. 
Lhe experiments with corn seem to indicate that mineral fertil- 
wzers alone are of comparatively little value for increasing the 
yields of the crops, while nitrogenous fertilizers with the minerals 
greatly increase the yields. In considering the yields alone the 
nitrogenous fertilizers are most profitable on this crop when used 
im quantities sufficient to supply from twenty-five to fifty pounds 
of nitrogen per acre, in connection with liberal quantities of phos- 
phoric acid and potash. But when the increased feeding value ts 
also considered, as tndicated by the percentages and total yields of 
protein per acre, even larger quantities of the nitrogenous fertil- 
zzers may sometimes prove economical, Ln these experiments in 
most cases the largest percentages of protein have been found, in 
both the corn and stover, from plots where the largest quantities 
of nitrogen have been used in the fertilizers. 
In contrast with corn, the experiments with legumes indicate 
that nitrogenous fertilizers increase the yteld but very little over 
that which ts obtained from the use of mineral fertilizers only. In 
the experiments with the cow pea fodder, the average of the results 
here reported shows essentially no advantage tn the use of the nitrog- 
enous fertilizers. The results of the experiments with soy beans 
grown for seed show some increase from the use of the nitrogenous 
fertilizers, but the increase was small, As regards the percent- 
ages and ytelds of protein in either cow peas or soy beans the 
results show very little increase accompanying the increase in the 
amount of nitrogen in the fertilizers. On the whole, therefore, 
the experiments appear to indicate that where an abundance of 
mineral fertilizers are available, nitrogen has very little effect in 
increasing either the total yield or feeding value of cow peas or 
soy beans.* 

* A more complete discussion of the effects of nitrogenous fertilizers upon the yields 
and the composition of certain grasses, grains, and legumes will be found on pp, 113- 
203 of the Report of this Station for 1898. 
