FIELD EXPERIMENTS WITH FERTILIZERS. ivjfet 
1895, the same arrangement of the plots and the same method 
of fertilizing them has been continued, namely those shown 
in the preceding diagram. But for the purpose of the later 
experiments the plots, which extend north and south, are sub- 
divided by paths crossing them from east to west, so that each 
plot contains six subdivisions or sections, each one-fiftieth of 
an acre in size. ‘The method of dividing the plots into sec- 
tions is illustrated by the diagram on page 172, which shows 
also the crop grown on each section. 
It is hardly to be expected that the effects of the fertilizers 
upon the yields of the crops can be determined as accurately 
from experiments made on plots of this size as from experi- 
ments made on larger plots. ‘This is a matter, however, that 
is already quite generally understood, so that the results of 
these experiments in this respect are neither novel nor striking. 
The more important object of the experiments, and one with 
which farmers are not so familiar, is the study of the effects of 
the nitrogen of the fertilizers upon the proportion of nitrogen 
in the crop. It is believed that in this respect the results are 
quite as reliable from the experiments made on the small plots 
as could be obtained if larger plots were used. The particular 
advantage in the small plots is that a larger number of crops 
can be used for the experiments. Three different crops were 
grown on each plot, and the number might have been six. 
The numbers of the plots in the diagram on page 172 are 
given at both ends of each plot. For convenience in referring 
to the sections they are designated by letters, A, B, C, etc., 
beginning with the section at the north end of each plot, and 
lettering to the south, as indicated for plots o and 64 in the dia- 
gram. A series of sections will include all the sections of the 
same letter. Thus, in discussing the experiments with corn, 
for instance, ‘‘ Series A’’ will include all the sections at the 
north ends of the ten plots, and ‘‘Series F’’ will include all 
the sections at the south ends of the plots. It will be observed 
that each crop is grown of: two sections of each plot; that is, 
upon two series of sections. In the accounts of some of the 
experiments the results from two series with the same crop are 
combined as if from a single series of sections twice the size of 
these: while in other experiments the results from each series 
are considered separately. 
