THE SOIL AND ITS IMPROVEMENT. 117 



wealth, not to squander it, but to develop it, use it, and finally re- 

 turn it to the soil from whence it came. The development of this 

 wealth is accomplished by drainage, cultivation, and green ma- 

 nures, and sometimes by the use of lime. The husbanding of 

 it is accomplished by growing, as far as possible, those crops 

 that can be fed on the farm, and by avoiding all wastes of ma- 

 nure, particularly of the liquid portion. For the improvement 

 of the soil we may safely adopt the following rules : 



Drain all land that requires it, not only removing surplus 

 water but admitting the air, without which development of plant 

 food can not take place. 



Cultivate thoroughly, thus still further favoring chemical 

 action. 



Keep the surface of the soil, when not growing a cultivated 

 crop, in grass or clover, thus avoiding waste of fertility by 

 drainage. 



Adopt such a rotation of crops as will give every cultivated 

 field a term in clover every few years. The exception to this 

 last rule is in the case of fields over-rich in humus. 



Use lime only on land over-rich in humus, or in connection 

 with green crops or barn-yard manure. 



Feed on the farm all crops that you can, and if you sell 

 grain largely, strive to balance the loss by the purchase of 

 bran, or other food from outside the farm. 



