125 



average gain of 2.1 tons of hay per acre, worth, at |6.67 

 per ton, |14.02. 



When the vines of the cowpea or velvet bean were 

 utilized as hav and onlv the roots and stubble employed 

 as fertilizer the increase in the yield per acre of the crop 

 immediatelv succeeding the stubble was as follows : 



208 pounds of seed cotton, or 18 per cent, worth $5.20. 

 4.3 bushels of corn, or 32 per cent.; 

 28 bushels of oats, or 334 per cent.; 



6.7 bushels of wheat, or 215 per cent.; 



2.08 tons of sorghum hay, or 57 per cent. 



The largest percentage increase from either the vines 

 or stubble of cowpeas or velvet beans was made by 

 wheat and fall sown oats, probably because these best 

 prevented the washing away or leaching out of the fer- 

 tilizing material in the stubble or vines of the legumes. 



Generally on sandy soil those crops most completely 

 utilize the fertilizing value of the legumes which leave 

 the land unoccupied for the shortest interval. It is 

 generally unad^isable for legumes to immediately suc- 

 ceed legumes in the rotation of crops, for non-legumi- 

 nous plants like cotton, corn, the small grains, grasses, 

 etc., make better use of the nitrogen of the fertilizing 



crop. 



The value of the increased product resulting from the 

 use of the entire legume for fertilizer was greater with 

 cotton and sorghum than with corn, oats or wheat. 



These experiments emphasize the importance of such 

 a rotation of crops as will require a large proportion 

 of the cultivated land of every farm to be devoted to 

 some leguminous plant. 



Comparing the fertilizing effect of the vines with that 

 of the stubble of the cowpea and the velvet bean, the 

 excess in the next crop in favor of the vines averaged 

 as follows: 



