1905.] PUBLIC DOCUMENT — No. 33. 125 



It will be noticed that the crops following soy beans have 

 as a rule showed little improvement which can be attributed 

 to that crop. So long as the soy bean was the legume grown, 

 the crops on the no-nitrogen plots continued in general to 

 decline, as compared with the crops ol)tained upon the nitrogen 

 plots. This is indicated l)y the fairly uniform and compara- 

 tively rapid fall in the line indicating the relative production. 

 The introduction of clover causes a marked rise in the line 

 indicating production, and this continues during the first 

 three seasons following the plowing of the clover sod. The 

 effect of the soy beans upon the crop of potatoes grown in 

 1902 appears to have been distinctly beneficial ; but, as Avas 

 stated in the fifteenth annual report, the fact that the potato 

 crop in 1902 suffered from blight undoubtedly favored the 

 plots where the growth was relatively feeble. In comment- 

 ing ui)on the results obtained in 1902, I said : — 



It may be that the relative standing of the no-nitrogen plots 

 is higher than it would have been had the crop of potatoes 

 grown to normal maturity. It will be remembered that blight 

 and rot prevailed to a considerable extent, and these would 

 naturally injure the potatoes with the ranker growth more than 

 those Avhere the growth was less luxuriant. It does not seem, 

 therefore, that we are justified in concluding that the after- 

 effect of the soy beans is as useful as the relation between the 

 figures appeal's to indicate. 



In view, then, of the doubt as to whether the true relative 

 capacity for product was shown in 1902, and the further 

 fact that all other years show a general agreement in not 

 indicating a decided benefit following the introduction of 

 the soy bean as a crop, Ave seem to be justified in the con- 

 clusion that the residual fertility left behind by the soy bean 

 is comparatively unimportant. 



II. — TiTE Relative Value ov Mliuate and IIkjh-grade 

 Sulfate of Potash. (Field B.) 

 The object in view in this exi)eriment is to test the relative 

 value of muriate and high-grade sulfate of potash Avhcn used 

 continuously upon the same soil. Tlu^ experiment Avas be- 

 gun in 1892. The potash salts Avere used for the period 



