126 ROTATION OF CROPS 



Farmers have learned by experience that wheat may profitably 

 follow a crop of tobacco. 



Our crops should also rotate in such a way that an abundance 

 of feed will be furnished for live stock at all times, so that the 

 farmer will not be under the necessity of buying any kind of feed 

 for his stock. 



A change of crops is likewise found necessary in order to keep 

 down the spread of weeds, plant diseases, and insect pests. Some 

 insects thrive on certain plants and disappear when these plants 

 are not grown. 



Advantages of Rotation. Summing up briefly, we may say 

 that the advantages of rotation of crops are as follows: 



1. It retards soil exhaustion and prolongs the period of profit- 

 able culture. 



2. The fertility of the soil is improved by the continuous growth 

 of crops properly grouped. When left lying idle, soils grow up to 

 weeds or are damaged by washing. 



3. A change of crops deprives insects of their special kind of 

 food and results in their removal or death. 



4. Weed pests which accompany certain crops may be eradicated 

 by proper selection of crops. Thus the dodder plant appears 

 as a pest in alfalfa and the so-called red rice frequently appears 

 as an enemy of the common rice plant. 



5. The growth of legumes in our scheme of rotation increases the 

 soil's store of nitrogen. 



6. Rotation gives a better distribution of labor and affords 

 continuous work for the farmer and his teams. 



7. A rotation which enables the farmer to market his crops at 

 different periods affords a better distribution of his income and 

 enables him to meet his obligations as fast as they mature. 



Examples of Rotation. A great many combinations of crops 

 are possible, but nearly all of them run for three, four, or five years. 

 Some of those in common use are as follows: 



1. Five-year Rotation 



IST YEAR 2o YEAB 3D YEAR 4xn YEAR 5rn YEAR 



Tobacco Wheat Wheat Clover Clover 



Corn Oats Wheat Clover Clover 



