GREEN-MANURES 239 



timothy and other grasses and can well be grown for hay, only 

 the sod being plowed under. Only in the case of very much 

 run down soils are these crops plowed under. Crimson 

 clover is an annual, and in the central and southern states 

 may be sown in the fall and plowed under in the late spring, 

 thus making use of a period of the year when the ground is 

 least likely to be occupied by a crop. Cowpeas, soy beans 

 and field peas must be raised during the summer months. 

 Vetch promises to be a satisfactory green-manure for winter 

 use in the northern states, when the cost of seed becomes 

 less than it is at present. 



Where it is desired to keep a crop on the soil during the 

 autumn, winter and spring, for the purpose of utilizing the 

 soluble plant-food material, the cereals, especially rye, are 

 useful. Buckwheat, on account of its ability to grow on poor 

 soil, is adapted to use as a green-manure, but it must be 

 grown in the summer or early fall. 



298. When green-manures may be used. — The most 

 economical way to use green-manures is between the regular 

 crops, rather than to lose a crop for the purpose of applying 

 green-manure. Between a small grain crop and a spring- 

 planted crop, there is usually opportunity for some green- 

 manure to be raised, even in the northern states. This crop 

 may be rye, vetch, buckwheat or rape and in the southern 

 states may be added crimson clover, which is perhaps best 

 for that region. In the South, however, there is much 

 more opportunity for the use of green-manure crops on ac- 

 count of the longer season. Where timothy and red clover 

 grow successfully, it is probably best to rely on the sod of 

 these crops to furnish green-manure rather than to attempt 

 any system that would necessitate dropping a crop from the 

 rotation. By a judicious fertilization of the hay crops, a 

 heavy sod may be produced, thus utilizing the inorganic 

 matter of the fertilizer to produce organic matter in the sod. 



