CROPS AND SOIL IMPROVEMENT 



fertility of the land, the percentage of nitrogen 

 taken from the air being greater in the case of 

 badly depleted soils. 



A big factor of error is found in the valuations 

 of the ingredients found in the crop. All plant- 

 food is worth to the farmer only what he can get 

 out of it. He may be able to use 50 pounds of 

 nitrogen per acre in the form of nitrate of soda, 

 at 18 cents a pound, when growing a certain crop, 

 but could not afford to buy, at market price of 

 organic nitrogen, all the nitrogen found in the 

 clover crop, and therefore it does not have that 

 value to him. 



On the other hand, these estimates do not em- 

 brace the great benefit to the physical condition 

 of the soil that results from the incorporation of a 

 large amount of vegetable matter. 



Discussion has been given to this phase of the 

 question in the interest of accuracy. Values are 

 only relative. The practical farmer can deter- 

 mine the estimate he should put upon clover only 

 by noting its effect upon yields in the crop-rota- 

 tion upon his own farm. It is our best means of 

 getting nitrogen from the air, it provides a large 

 amount of organic matter, it feeds in subsoil as 

 well as in top soil, bringing up fertility and fill- 



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