192 



NITROGEN, PHOSPHORUS AND POTASSIUM 



"Certain things are to be sown, not with the hope of any 

 immediate profit being derived from them, but with a view to the 

 following year, because being plowed in and left in the ground, 

 they render the soil afterwards more fruitful." 



Crops for Green Manuring. Many crops may be used for 

 plowing under: legumes, rye, buckwheat, rape, oats, etc. The 



Fia. 128. A, Hairy vetch. B, Crimson clover. (U. S. D. A.) 



clovers and vetch (Fig. 128) can be seeded one year with grain 

 and turned under in the fall or in late spring. Alsike clover is suit- 

 able for low lands. Mammoth clover is well adapted for poor soils 

 to get rank growth. 



Cowpeas, soybeans (Fig. 129), rape, and crimson clover 3 may 

 be sown in between the rows when a cultivated crop is "laid by." 4 



3 Crimson clover is commonly grown as a green manuring and forage crop 

 along the Atlantic seaboard from New Jersey to the Gulf States. 



4 "Laid by" means last cultivation. 



