GREEN MANURES AND COVER CROPS 57 



of satisfaction. The customary sowing is about two 

 bushels of seed to the acre covering with a harrow. 



loi. Soy bean, also a legume, succeeds better on heavy 

 soils and in cool climates than the cowpea and is, there- 

 fore, valued by some northern growers as well as south- 

 ern truckers for manurial purposes. The seed may be 

 sown broadcast or in drills. Cultivation is a great benefit 

 to the crop. 



102. Fertilizing green manurial crops. — When crops 

 for manurial purposes are grown on impoverished soils, 

 commercial fertilizers should be used liberally enough 

 to encourage a good growth. It may pay to use 500 

 pounds to the acre of a high-grade fertilizer. Nitrogen 

 is especially important for the nonlegumes. 



103. When to plow under green crops. — No very defi- 

 nite advice can be given upon this question, because 

 many factors must be taken into account, such as kind 

 and age of crop, vegetables to follow, needs of the soil 

 and seasonal conditions. The older the crop the more 

 time will be required for its decomposition and the less 

 benefit it will be to the next cash crop. Soil moisture 

 problems are especially important in connection with 

 green manures. When plowing is delayed too long, the 

 ground may become too dry for successful sowing or 

 transplanting. To prevent serious interference with the 

 capillary movement of the soil moisture, the furrow slice 

 should be stood on edge as much as possible rather than 

 turned flat. Rolling or dragging immediately after 

 plowing is regarded as valuable in preventing the devel- 

 opment of soil acidity- 



