202 BOARD OF AGRICULTURE. [Pub. Doc. 



composition of the crops. In the experiment with mixed 

 grasses there was a small proportion of clover on all of the 

 plots, but in most cases not enough to materially lessen the 

 value of the comparative results. In the case of the plots 

 supplied with mineral fertilizers only, however, the propor- 

 tion of clover was much larger than on the other plots, and 

 the percentage of protein in the crop from these plots was 

 correspondingly high. In judging of the eifect of nitrogen 

 as compared with mineral fertilizers, it will be necessary to 

 take this into consideration. In one of the experiments, 

 for a single season, samples were taken of the pure grasses 

 only on one of the mixed mineral plots. It was found that, 

 where the clover was excluded from the sample, the amount 

 of protein was 7.2 per cent; while for a mixed sample, 

 which was an average of the entire growth on the plot, 

 there was nearly 11 per cent. If we were to assume that 

 the average percentage of protein found in the grasses (ex- 

 clusive of clover) on the mineral plots was about 7 per cent, 

 the comparison of the results would doubtless be more 

 accurate. With 25 pounds of nitrogen the percentage of 

 protein was 7.75 per cent, while with 50 pounds it was in- 

 creased to 8.5 per cent, and with 75 pounds to 9.4 per cent. 

 The percentages of protein obtained in similar experiments 

 with oats, corn and cow-pea fodder are also given. The 

 influence of nitrogen on the protein of the seed of corn and 

 oats was even more striking than on the straw and stover ; 

 but the results on the seed have been omitted, in order to 

 confine our discussion to fodder articles. In the case of 

 oat straw, the mineral fertilizers alone gave a slightly 

 higher percentage of protein than where 25 pounds of nitro- 

 gen were added. This may, perhaps, be accounted for by 

 the fact that the number of experiments upon oats was 

 fewer than with most of the other crops. The protein in 

 the straw increased quite rapidly with the use of 50 and 75 

 pounds of nitrogen per acre. In the corn stover there was 

 a gradual increase in the percentage of protein, correspond- 

 ing fairly regularly with the increase in the amount of 

 nitrogen used. In the case of the cow-pea fodder, the per- 

 centage of nitrogen on the mineral plots was larger than on 



