CEREAL CULTIVATION EASTERN AREA 317 



any cereal on the same land results in depleted soil fertil- 

 ity, poor condition of the soil, increase of weeds, mixtures 

 of cereal varieties, and low yields. A rotation of cereal 

 crops alone is little better. A perfect rotation series 

 must include a legume and a cultivated crop. As to 

 other details, local conditions will determine the nature 

 of the rotation and particular crops to be used. In the 

 North, the clovers are the chief legumes, and corn and 

 tobacco the cultivated crops. In the South, cowpeas, 

 soybeans, vetch, crimson clover, and lespedeza are the 

 chief legumes, and cotton and corn the cultivated crops. 



343. Examples of rotations for the North. For all 

 the North Central and Eastern states, including the 

 " corn belt" (97), there is probably no better rotation for 

 general purposes than the 4-year rotation previously 

 mentioned (339) as so successful in Ohio corn, oats, 

 wheat, and clover. The chief cereals are employed, the 

 chief legume and the main cultivated crop. The order 

 in which the crops occur is also good from all standpoints. 

 If a meadow grass is wanted, 2 years of timothy may be 

 added, making a 6-year rotation. In tobacco districts 

 this crop may take the place of oats. In other places 

 where oats do not pay, barley may be substituted or wheat 

 grown twice, or another legume, such as cowpeas, may 

 be inserted if adapted. 



Much the best yields of wheat were obtained at the 

 Ohio Experiment Station in a rotation including potatoes 

 (potatoes-wheat-clover), but the potato acreage is ordi- 

 narily too limited to be practical in a rotation of large 

 fields. In Maine, however, a potatoes-oats-clover rota- 

 tion is practiced. In Iowa and Illinois, in both the oat 

 and corn belts, a common rotation consists of corn, 

 oats, and grass or clover. It is usually a 5-year rotation, 



