ON LIVE STOCK FOOD 



Just how the leguminous plants came to develop 

 this anomalous habit of serving as hosts for the 

 particular types of bacteria that can aid them by 

 the extraction of nitrogen from the air, it is diffi- 

 cult to understand. But the fact that they have 

 developed the habit is of very great importance, 

 because it enables these plants to enrich the nitro- 

 gen content of the soil in which they grow, instead 

 of impoverishing it as do other plants. 



By turning the clover under with a plow, the 

 farmer is enabled to restore to the soil an equiva- 

 lent of the nitrogen that was taken from it in a 

 preceding season by other crops. 



The importance of this will be obvious to 

 anyone who is aware that nitrogen is an absolute 

 essential as a constituent of a soil on which good 

 crops of any cultivated plant are to be grown, and 

 who further understands that the available supply 

 of nitrogenous salts with which a depleted soil may 

 be restored has until recently been very limited. 



Some readers may recall the prediction made 

 not many years ago by the English chemist, Sir 

 William Crookes, to the effect that the world 

 would presently suffer from a niti'ogen famine that 

 would greatly reduce the wheat crop, and perhaps 

 subject the entire race to danger of starvation. At 

 that time the chief supply of nitrates came from 

 the nitrate beds of Chile; and it had been estimated 



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