FIELD EXPERIMENTS WITH FERTILIZERS. 49 
It will be noticed from Tables 1o and 11 that the amounts of 
both dry matter and protein in the crop increased as the amounts 
of nitrogen in the fertilizers increased, but that the increase in 
the yield of protein was relatively larger than the increase in 
the yield of dry matter. This is shown especially in the last 
two columns of the tables, which compare by percentages the 
yields of dry matter and of protein from the different sections 
supplied with nitrogen with the average of the yields from the 
_ two sections having the mineral fertilizers only, the latter being 
taken as a basis (100). These figures bring out clearly the 
fact that the increase in the amount of protein in the crop fol- 
lowing the use of nitrogenous fertilizers is due not only to an 
increase in the total yields of the crop, but also to an increase 
in the proportion of protein in the crops from the plots upon 
which the larger quantities of nitrogen were used, showing 
that the nitrogen in the fertilizer had a relatively greater tend- 
ency to increase the proportion of protein in the crop than it 
had to increase the total yield of dry matter. 
EXPERIMENTS WITH COW PEAS. 
From the diagram on page 36 it may be seen that the two 
adjoining series of sections, C and D, were used for the expert- 
ments with cow peas. Each section contains one-fiftieth of an 
acre, but the results obtained on the two series have been com- 
bined, and are given in the following tables as if one series of 
sections of one-twenty-fifth acre each was used. ‘The Clay 
variety of cow peas has been used for several years. The seed 
is obtained from the South each year. Most varieties of cow 
peas do not ripen their seed in this climate. The crop is har- 
vested before or at the time of blossoming, and is used for fodder. 
The amounts and costs of the fertilizers per acre, the yields 
of crop per section as harvested, and the calculated yields per 
acre are given in Table 12. The percentages and amounts of 
dry matter in the crop as harvested and the percentages and 
amounts of protein in the dry matter are given in Table 13. 
The amounts of nitrogen in the fertilizer and the total yields of 
the crop.—The effects of the nitrogen of the fertilizer on the 
total yields of crop are indicated by the results given in Table 
12, From the figures in this table it will be seen that the yields 
