l6 THE COW PEA. 



tions, its power to take nitrogen from the air, and its 

 wonderful economy in the use of potash and phosphoric 

 acid make it, all in all, one of the most wonderful plants 

 recently introduced to the northern farmer. 



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 that 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 

 these cannot be made from nitrogen alone. Not one atom of 

 nitrogen can be assimilated unless there are also present cer- 

 tain 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 is possible 

 when potash, phosphoric acid and nitrogen are not present 

 and available, and no oversupply of one plant food element 

 can compensate for the absence or scarcity of another, Each 



