0-7 



Is NlTIUKJKN AnVANTACilOOrS IN A l^KK TIMZKR FOR 



COWI'KAS? 



C<)W]K*as are able (o i^row on poorer soil Mian is cot- 

 ton (u- corn. Tliis is becanse the eowpea })lant, llii'on<i;;h 

 the agenev of tin* specific enlar«4ements or tubercles 

 or nndnles on its roots, is able to draw a ])art of its 

 nitroncn from ilie air, while corn, cotton, <;rasses, etc., 

 are entirely dependent for their nitrogen on the soil and 

 fertilizci*. 



Since the cowpea plant possesses this source of sup- 

 ply it is reasonable to assume that nitrogen can be 

 omitted from its fertilizer, thus reducing the cost of fer- 

 tilization. On the other hand it has been stated that 

 during the early period in the life of this plant the 

 tubercles afford no nitrogen, and that nitrogenous fer- 

 tilizers are beneficial during this early period. One 

 writer has recorded as his observation that co'tton seed 

 meal is a suitable fertilizer for cowpeas. 



To put this latter statement to a test, four plots of 

 drilled cowpeas in 1898 were employed. All were fer- 

 tilized with 240 pounds of acid phosphate and 48 pounds 

 of muriate of potash per acre. Two plots received in 

 addition cotton seed meal at the rate of 100 pounds per 

 acre. The cured hay averaged practically 2^/2 tons 

 per acre, . the plots with cotton seed meal affording 

 only 40 pounds of hay per acre in ext-ess of the outliers. 

 There was a practical equality in yield, and a failure of 

 cotton seed meal to exert any appreciable effect. 



This is in accord with nearly all of the published fer- 

 tilizer experiments with coT\T)eas. 



We have found the tubercles on cowpeas when the 

 plants Avere only a few inches high and a few T^'eelvS 

 old. Apparently the nitrogen in the seed and that which 

 even a poor soil yields is usually sufficient for the little 



