408 FARM MANAGEMENT 



is often lost and land rendered less valuable through 

 erosion of the soil. On rough, hilly land and in light 

 soils the loss from this source often becomes serious. 

 The valuable surface soil is washed into the ravines 

 and valleys, the fields become gullied and difficult to 

 work, and are consequently unproductive. Erosion 

 can be prevented to a large extent by keeping the land 

 in grass a good portion of the time, thus rilling the soil 

 with roots, by the addition of manures, and by plowing, 

 planting, and cultivating across the face of the hills 

 instead of up and down the hills. 



CROP ROTATION 



The proper rotation of crops is regarded as essential 

 in keeping up the producing power of the soil. It also 

 becomes an important factor in the profit from farming 

 because of its bearing on the farm labor and on the 

 constant employment of capital as well as upon the 

 fertility of the fields. Farm crops are divided roughly 

 into three classes so far as their effect on the soil is 

 concerned. These classes are: (i) grain crops, in- 

 cluding all of the cereals grown for the grain they 

 produce; (2) grass crops, including all of the crops 

 usually grown for pasture or hay; and (3) the culti- 

 vated crops in which are included corn, potatoes, root 

 crops, and any others which are so grown as tc call for 

 intertillage. 



The grain crops are practically neutral in regard to 

 the addition or reduction of the amount of decaying 

 vegetable matter, or humus, in the soil and may be 

 grown continuously for a few years without appar- 

 ently affecting soil productivity. Long-continued grain 

 cropping, however, results in weedy fields and lessened 



