8 STORRS AGRICULTURAL EXPERIMENT STATION. 



oats and cow peas or soy beans are grown in a four-year rota- 

 tion. The object of the experiment is to study the capacity of 

 the soil to supply the fertilizing ingredients mentioned, and 

 the particular needs of the crops for any or all of them. The 

 experiment of 1901 was with soy beans. The deduction from 

 the results of this test are in accord with those of previous 

 years. From the results obtained during the twelve years of 

 experimenting in this particular field, it appears that the fer- 

 tilizing ingredients most needed have varied with the crop; 

 that is to say, the peculiarities of the plant have had as much 

 or more to do with deciding the demand for fertilizers than 

 any special deficiency of the soil. Cow peas and soy beans 

 have been benefited by phosphoric acid and potash, but have 

 paid little heed to nitrogen. Corn and oats have responded 

 well to nitrogen, and both have been helped by phosphoric 

 acid, but neither has been much increased by potash. Pota- 

 toes have been benefited by all three ingredients, and espe- 

 cially helped by potash. 



Special nitrogen experimcjit. — The object of these experi- 

 ments is to obtain information regarding the effects of nitro- 

 gen in different fertilizers upon the yield, and more especially 

 the composition of different crops. In carrying out these 

 experiments the crops are grown on a series of parallel plots 

 some of which are without fertilizer, some with definite quan- 

 tities of mineral fertilizers only, and others with the mineral 

 fertilizers and varying quantities of nitrogen. The effect of 

 the nitrogen upon the total yield of the crop is estimated by 

 comparing the yields from the plots having the mineral fertili- 

 zers alone with those from the plots having different quantities 

 of nitrogen in addition to the minerals; the effect upon the 

 composition of the crop is likewise estimated by analyzing 

 samples of the crops from the different plots. These experi- 

 ments are made each year with corn, cow peas and soy beans, 

 that of 1901 being the seventh in a consecutive series on the 

 same plots. The results of the seven years of experiment 

 with these three crops indicate that with the cereals, the effect 

 of the nitrogenous fertilizer is to increase both the total yield 

 of the crop and the proportion of protein, thus in a two-fold 

 way increasing the food value; while with the legumes the 

 nitrogen of the fertilizers has very little effect upon either 



