124 



wliicli is o(i[uiviilont to tlie Tiitr()«^vu in 1,003 pounds 

 of cotton siH^d meal. 



In tlic roots, stubble and fjilb'u leaves on an acre 

 there were, resi>ectively, 11.05, 1(;.2 and 31.4 pounds of 

 nitrogen, an average of 19.75 pounds of nitrogen per 

 acre, which is equivalent to tliat contained in 2S2 ]>ounds 

 of cotton seed meal. 



The average of three tests shows that 28 per cent, of 

 the total nitrogen wa« contained in the roots, stubble 

 and fallen leaves after the removal of the hay. 



The average increase in the yields of succeeding crops 

 was practically identical whether the fertilizing mate- 

 rial was supplied by cowpeas or by velvet beans. E(iual 

 areas of these two plants were of practically eciual value 

 for soil improvement. 



The word vines is here used as synonymous with the 

 entire plant of the velvet bean, and with the entire plant 

 of the cowpea after the pods are picked. 



The increase in the yield of seed cotton produced in 

 the year immediately following the plowing in of the 

 vines of cowi>eas or velvet beans averaged in four tests 

 5G7 pounds per acre, worth (at 6J cents per pound for 

 lint and |7.50 per ton for seed) |14.17. The increase 

 in the fii-st cotton crop after the use as fertilizers of 

 the vines of the summer legumes was never less than 

 32 i^er cent, and averaged 63 per cent. 



In one test with corn the increase in the first crop 

 where velvet bean vines had been plowed in was 81 

 per cent., of 12.3 bushels, worth at least $6.15 per acre. 

 With oats the average increase from the vines of the 

 summer legumes in three tests averaged 17 bushels per 

 acre, and with wheat the corresponding increase in two 

 tests was 5.65 bushels per acre. 



The increase in the yield of sorghum hay after cow- 

 pea and velvet bean vines averaged 87 per cent., or an 



