Double Cropping Systems Involving No-Tillage and Conventional Tillage
1973
Sanford, J. O. | Myhre, D. L. | Merwine, Norman C.
This study was prompted by the huge feed grain deficits which increase annually in the Southeast. The need exists to find ways of increasing grain production efficiently. Cropping-tillage systems designed to accomplish this were studied. Soybeans [Glycine max (L.) Merr.] and grain sorghum [Sorghum bicolor (L.) Moench.] were double cropped following wheat (Triticum aestivum L.) on a Blackbelt soil. No-tillage and conventional tillage methods were compared for soybeans and grain sorghum; Conventional tillage was used for wheat. The 2-year average yield of soybeans was 1,708 kg/ha (25.4 bu/acre) for no-tillage and 2,250 kg/ha (33.4 acre) for conventional tillage. This difference was significant (P = .05) and was due mainly to lack of nutsedge (Cyperus sp.) control by herbicide alone in no-tillage plots. In the third year when the crop was hand-hoed, no yield differences occurred due to tillage methods. The 2-year average yield of grain sorghum was 3,249 kg/ha (48.3 bu/acre) for no-tillage and 3,868 kg/ha (57.5 bu/acre) for conventional tillage. When the crop was handhoed yield of grain sorghum was significantly higher for no-tillage (5,072 vs 4.335 kg/ha). Wheat grown after soybeans yielded significantly (P = .05) more than wheat grown after grain sorghum. This difference was attributed primarily to the bneficial effect of residual N from the previous crop of soybeans. Based on current costs and prices, the soybean-wheat double cropping system produced significantly higher net returns over specified production costs than the wheat. grain sorghum system.
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