CHAPTER VII. 



ROTATION OF CROPS. 



Many of the problems that confront the 

 farmer of the present day might have been 

 avoided had Rotation of Crops been more often 

 practiced by our fathers. The productiveness 

 of the soil cannot continue for any considerable 

 length of time unless rotation, or change of 

 crops, is practiced, or fertilizers heavily applied. 



.4. INFLUENCE OF ROTATION UPON PLANT- 

 FOOD. 



I. Preserves Food Supply. 



i. Prevents Exhaustion. Different plants re- 

 quire different proportions of the various foods. 

 If the same crop as, wheat or cotton is grown 

 continuously for a number of years, the soil in 

 that field may become so deficient in certain 

 elements essential to that particular crop as to 

 very materially lessen the yield ; while if some 

 other crop, as clover, be sown, the yield may be 

 very heavy, and hence the crop may be more 

 profitable, even at a lower price. Crops should 

 be so selected that different plant-foods or, at 

 least, different proportions of the plant-foods 

 will be demanded from the soil each year. 



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