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FIELD EXPERIMENTS WITH FERTILIZERS. 179 
From these weighings and the size of the plots the correspond- 
ing yields per acre are calculated. By comparing the yields from 
the sections having different kinds and amounts of fertilizers 
the effect of the different fertilizers upon the yields may be 
estimated. 
As might be expected, the yields from the sections of plots o 
and oo, which have received no fertilizer for over ten years, 
are poor. The yields from the section of plots 6a and 64, which 
have only the mineral fertilizers, are much better than might 
be expected in consideration of the fact that no nitrogenous 
fertilizers of any kind have been applied upon these plots for 
more than ten years. In this respect the results of the 
experiments with corn are much better than those obtained in 
experiments with common grasses, such as timothy or red top, 
under similar conditions. This accords with the belief that 
corn may be better able than the common grasses to gather 
nitrogen from natural sources in the soil. 
In the average of the results from both series of sections A 
and F for 1898 and 1899 the yields from the sections of plot 7, 
with the smaller ration of nitrate of soda, are smaller than 
those from the sections of the mineral plots, 6a and 66. This 
smaller yield with nitrogenous fertilizers than without them 
is unusual, and the explanation is not apparent. 
In comparing the yieldsof shelled corn from the sections of the 
different plots it will be noticed that, with one exception, the 
yields from the sections of the nitrate of soda group of ‘plots, 7, 
8,andog, are largest from plot 9, upon which the largest ration— 
seventy-five pounds per acre—of nitrogen is used. It will be 
observed, however, that the yields from plot 9 are but little 
larger than those from plot 8, upon which only fifty pounds of 
nitrogen per acre are used; while in the exception noted above © 
in 1899 the yield from section A of plot 8 was larger than that 
from the same section of any other plot. This generally small 
increase in yield of crop accompanying a relatively large increase 
in the quantity of nitrogen in the fertilizers would seem to in- 
dicate that the corn in this case could not utilize profitably the 
larger quautities of nitrogen when supplied in a readily soluble 
fertilizer such as nitrate of soda. 
