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Show Increased Profits and Yields by Rotation Erosion Controlled by Proper Farm Planning i The growing of intertilled crops such as corn and soybeans not only uses plant food faster, but the loss from erosion is greater too, on rolling roll-ing land, according to careful checks made at Iowa State college. To overcome this condition rota-lion rota-lion is important. The first requirement require-ment of a good crop rotation is that it contains plenty of legumes. Sod crops of legume-grass combination produce much feed per acre, and in addition, they: Increase the yields of other crops' in the rotation. ' ' Help maintain soil fertility, particularly par-ticularly the nitrogen and organic matter. Produce good soil tilth. Help control erosion. Where corn was grown in a four-year four-year rotation of corn, oats, followed by clover and timothy for two years, the yield of corn was 32, bushels higher than when grown in a corn-oats rotation. In poor crop years, the difference in yield may be smaller than those obtained in the good crop years of 1942 to 1944. However, the difference between the f C"1 1 lacruu in com yield from Irf j-c I Mi mniem !t.ru i IU ntitlon SlOC. 98 ' h n I S "Z 1 I. 2-VM8 2-VtAR 4-VTAR KOTATION ROIATION ROTATION. COW-OAT COtM-OArt. COIN-OATS-(fMtrtCLOVIH M CADOW CATCH CXjOO ULAOOW Legumes in rotation increase the yield of corn. Marshall silt loam, Soil Conservation Experimental Farm, Clarinda, la. (Years 1912-44.) poor and good rotations will probably prob-ably become greater the longer the treatments are continued. One of the most important reasons rea-sons why crop yields decrease when land is kept in grain crops such as corn and oats is that these crops lower the nitrogen and organic matter mat-ter content of soils. |