CROPS AND SOIL IMPROVEMENT 



substitution gives more value in the crop follow- 

 ing corn, and at the same time conserves soil 

 fertility. 



Where land is thin, a four years' rotation of 

 corn, soybeans or cowpeas, wheat, and clover is 

 one of the best, because it contains two legumi- 

 nous crops, and because one of them favors the 

 wheat which follows and the clover seeded in the 

 wheat. 



Potatoes after Corn. When potatoes are 

 grown in the corn belt, a five years' rotation of 

 corn, potatoes, oats, wheat, and clover, or corn, 

 potatoes, wheat, clover, and timothy, is one of the 

 best. When a late potato crop is grown, there is 

 not time for seeding to wheat in cool latitudes, 

 and the oat crop, or the soybean, fits in best. 

 Farther south, where the oat crop is less profitable, 

 there usually is time to go directly to wheat. 



The advantage in this rotation is that the fresh 

 manure can be used on the sod for the corn, and 

 the potato thrives in the rotted remains of the 

 sod and manure. Corn leaves the soil in good 

 physical condition for the potato. Commer- 

 cial fertilizer is used freely for the potato, which 

 repays fertilization in higher degree than most 

 other staple crops. The land can be prepared for 



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