56 HATCH EXPERIMENT STATION. [Jan. 



Leguminous Crops (Clover, Pea and Bean or "Pod" 

 Family) as Nitrogen Gatherers. (Field A.) 



This experiment is a continuation of a series begun in 

 1889. The objects in view have been : — 



1. To determine the extent to which plants of the clover 

 family are capable of enriching the soil in nitrogen taken by 

 them from the air through the agency of the nodular bacteria 

 found upon their roots. 



2. To compare nitrate of soda, sulphate of ammonia, 

 dried blood and farm-yard manure as sources of nitrogen.* 



The plots, eleven in number, are one-tenth acre each, and 

 are numbered to 10. Three plots (4, 7 and 9) have re- 

 ceived no nitrogen-containing manure or fertilizers since 

 1884; one (0) has received farm-yard manure; two (1 and 

 2), nitrate of soda; three (5, 6, and 8), sulphate of ammo- 

 nia; and two (3 and 10), dried blood every year since 

 1889. These materials have been used in amounts to fur- 

 nish nitrogen at the rate of 45 pounds per acre each year. 



All the plots have received yearly equal quantities of 

 phosphoric acid and potash; viz., 80 pounds per acre of 

 the former and 125 pounds of the latter from 1889 to 1894 

 and the past two seasons; but in 1894 and 1895, double 

 these quantities. To some of the plots the potash is ap- 

 plied in the form of potash-magnesia sulphate ; to others, in 

 the form of muriate. The results with the former salt have 

 been superior to those with the latter, as a rule, particularly 

 when used in connection with sulphate of ammonia. 



Up to this year we may briefly characterize the results, in 

 so far as these have a bearing upon the two main questions 

 proposed, as follows : — 



1. The leguminous crops grown (soy beans in 1892, 

 1894 and 1896) have not appeared to enrich the soil in 

 nitrogen, if we accept the results with the next following 

 crop as affording a basis of judgment. 



2. The different sources of nitrogen have ranked on the 



* Only such details are given here as are necessary to an understanding of the 

 nature of the experiment. Full particulars will be found in our ninth and tenth 

 annual reports. 



