Crimson Clorer and Sand Vrlch 



251 



in the nitrogen-gathering power of crimson clover on 

 different soils and in different seasons. Rainfall, tem- 

 perature, humus, and the supply of lime, phosphoric 

 acid and potash, aside from many other factors, play an 

 important role. In 

 general, the amount 

 of nitrogen in a crop 

 of crimson clover 

 may range from 50 

 pounds per acre, or 

 less, to 200 pounds 

 per acre or more. In 

 the experiments of 

 the Delaware sta- 

 tion, already cited, 

 the yield of nitro- 

 gen per acre was 

 from- 139 to 188 

 pounds. 



The sand vetch 

 (Vicia villosa) is an- 

 other crop that has 

 been employed suc- 

 cessfully as a green- 

 manure on light 

 soils. It is a hardy plant that will thrive on poor 

 lands and will stand cold weather well. It has been 

 recommended as a cover-crop for the tobacco soils in 

 the Connecticut valley. It is stated by the Connecticut 

 station in this connection that it survived in spots where 

 rye was completely winter-killed. " In one portion of a 



Fig. 44. A bunch of crimson clover plants. The 

 mas.s of fibrous roots indicates a wonder- 

 ful feeding capacity and explains its rapid 

 and early growth. 



