THE COW PEA. IS 



FERTILIZING FOR COW PEAS. 



Cow peas are so commonly recommended for green 

 manuring, that the impression prevails that the growing 

 plant itself needs no fertilizer. This is a mistake and often 

 a serious one; the more it is fed the more food will it store 

 up for the crop which follows. It is true the cow pea has 

 power to draw nitrogen from the air, and use it for its own 

 growth, but for every pound of nitrogen thus absorbed, more 

 than a pound of potash and considerable phosphoric acid 

 must also be taken up; the latter two ingredients do not 

 exist in the air, so they must be supplied artificially. The 

 nitrogen absorbed by the cow pea plant enters into and 

 forms a part of the entire living plant and dry stubble, but 

 cannot be made from nitrogen alone; not one atom of nitro- 

 gen can be assimilated unless there are also present certain 

 amounts of potash and phosphoric acid. The growing cow 

 pea must get its potash and phosphoric acid, just as cotton, 

 just as corn, just as every other growing plant gets them, — 

 from the soil to which they must be applied in the shape of 

 a fertilizer. No plant growth whatever are possible when 

 potash, phosphoric acid and nitrogen are not present and 

 available, and no over-supply of one plant food element can 

 compensate for the absence or scarcity of another. Each 

 must be present and in the proper proportion, otherwise 

 there cannot be a full growth. While cow peas do have 

 the properly of drawing nitrogen from the air, nevertheless, 

 a certain amount of this ingredient is required in the soil 

 in which they grow and must be artificially supplied, if not 



