173 



extra value of the first crop after \anes, as compared 

 with stubble, we have a total credit for the vines when 

 used as fertilizer of $11.53 per acre in comparison with 

 the value of the cowpea and velvet bean hay when uti- 

 lized as stock food. The average yield of cowpea hay 

 from the stubble plots was 3,278 pounds per acre, and 

 of velvet bean hay 4,781 pounds, or a collective average 

 of 1,030 pounds of legume hay per acre At $10 per 

 ton, this would be worth |20.15 per acre. Subtracting 

 from this, |9.50 m above, we have $8.47 as the dif- 

 ference in the first year's profits in favor of utilizing the 

 vines as ha v. However, other factors must be consider- 

 ed before we have satisfactorily determined whether 

 it was most profitable to use tlie ^ines after picking the 

 peas or to utilize the tops of both coT\i)eas and velvet 

 beans for hay; chief amono- these factors are the rela- 

 tive residual fertilizing values of \ines and stubble as 

 shown bv differences in the vield of the second and 

 subsequent crops after legumes. 



What is the Fertilizing Effect of Vines and Stubble 



OF COWPEAS ON THE SECOND CrOP AFTER THE 



Legume? 



The answer is found in the following table : 



Average increase in second crop after legumes. 



In the second crop after the legumes there was in 

 every case a considerable increase attributable to the 

 use of the vines a§ fertilizer. 



