68 GENERAL CONSIDERATIONS 



summer. The corn crop, together with the pasturage 

 afforded by the peas in the fall and the vetch in 

 early spring, will more than repay the phosphate and 

 labor required. A very few years of this treatment 

 will restore the poorest, most exhausted fields and 

 make them as productive as the best virgin lands. 



The spring vetch (^Vicia sativd) grows in much the 

 same way as the hairy vetch. It, too, is a useful plant, 

 but it does not make as heavy a mass of vegetation as 

 the other. The vetches are not well adapted to the 

 tropics. 



The cowpea ( Vigna Catjang'^') is, without doubt, the 

 one most important legume for Southern agricul- 

 ture. It has often been called the clover of the South, 

 since it plays the same leading role here that red 

 clover does at the North. It is a rank-growing an- 

 nual, completing its growth in about three months. 

 Being of tropical origin, it delights in hot weather 

 and does not succeed well durinof the cooler months. 

 Its short growing season makes it possible to grow 

 it as a manurial crop at times when the land would 

 otherwise be unoccupied, as, for instance, after a crop 

 of winter oats or rye or after an early spring crop 

 of vegetables. It is most widely used, however, to 

 plant between the rows of corn at the time of 

 the last cultivation when the crop is being laid by. 

 It can in like manner be very profitably used on 

 cane plantations to sow between the cane as a cover 

 crop at the beginning of the rainy season. The peas 



1 Wight (U. S. Dept. of Agric, Bureau of Plant Industry, Bull. 

 102) shows that most of the varieties of cowpeas should be re- 

 ferred to Vigna unguiculata rather than to V. Catjang. 



