EXPERIMENTS WITH NITROGEN FERTILIZERS 



11 



The inferiority of the crop of 1903 was due to the season, which was reported 

 to be "highly unfavorable to the growth of the crop, which is one requiring 

 protracted warm weather." 



The relative effectiveness of the different nitrogen fertilizers is again difficult 

 to measure. In the first year, 1892, the nitrate plots stood out as superior; but 

 after Plot 8 was hmed in 1894, the two best ammonia plots exceeded the nitrate 

 plots both in that year and in 1896. In the matured crops of 1901 and 1903, the 

 manure plot was slightly superior to the average of any other pair of plots. The 

 ammonia plots in 1903 appeared to have lost the benefit of the liming, which aU 

 plots received five years earlier in 1898. 



Brooks mentioned an interesting observation about the nitrate plots in his 

 report for 1903: 



It has been repeatedly noticed that where nitrate of soda is the source of nitrogen, the leaves, 

 especially in the early stages of growth, assume a crinkled or wrinkled appearance, and fail to 



reach full size and normal development As the season advances, the soy bean plants as a 



rule show a more normal leaf development; and, although the crinkling this season was excessive, 

 the yield on the nitrate of soda plots does not appear to have been materially decreased, as a 

 consequence. 



The ratio of seed to straw was nearly constant for the crops on manure, 

 nitrate, and organic nitrogen plots, 1 : 1.41-1.45. Ammonia gave a wider ratio, 

 1.61 and 1.57, while mthout nitrogen the ratio varied from 1.50 to 1.67. 



Soy beans, although a legume, were always benefited by nitrogen fertilizers; 

 but no one of them was consistently most efficient. 



Table 3 — Yield of Soy Beans 



(Pounds per plot.) 



♦Lime applied. 



Potatoes 



Since potatoes were associated with the soy bean crops, their group will be 

 discussed next. 



The crop of 1900 followed a crop of mixed clover and grass, and consequently 

 had a sod turned under as a preparation for it. The next two crops had only soy 



