THE COW PEA. 41 



Cow peas cut for hay are more or less immature; in the 

 fully mature crop the plant food percentages change, that of 

 potash especially, becoming considerably larger. 



The assertion has been made that the cow pea crop 

 leaves the soil in better condition J than it found it, which 

 is strictly true only when the whole crop is turned under 

 for manure, green manuring. The cow pea, like every 

 other legume, harvested or removed from the grountl 

 where grown, leaves the soil as rich in nitrogen as before 

 it was planted, but unless, while it is growing, potash 

 and phosphoric acid are supplied fully to satisfy its hunger 

 for them, it actually leaves the soil much poorer than it 

 found it. The great value of the growing cow pea, next to 

 its power of taking nitrogen from the air, is its wonderful 

 ability to utilize potash and phosphoric acid. Wnen these 

 minerals are liberally used on the cow pea crop, the soil 

 gains far more than the cost of the fertilizer, the growth is 

 much larger and more rank and the atmospheric nitrogen 

 secured corresponds in abundance. 



