Reduction of Soil Erosion by the No-Till System in the Southern Piedmont

Abstract

ABSTRACT SOIL erosion control of row-cropped, Southern Piedmont lands is a constant problem. A 2.71 ha (6.70 acre) watershed, with an average slope of 3.4 percent, was equipped with a 0.76 m (2.5 ft) H-flume in summer of 1972 to study runoff and soil losses from row crop land. The watershed treatments were con-ventional till, without terraces or grassed waterways, during the first 2 yr in a soybean {Glycine max (L.) Merr.)-fallow sequence, and then 2 yr of no-till double cropped barley (Hordeum vulgare L.), followed by grain sorghum {Sorghum vulgare Pers.) with fescue {Festuca arundinacea Schreb) grassed waterway. Annual runoff was decreased from 22.5 cm (17.6 percent) with con-ventional tillage to 12.0 cm (9.7 percent) with double cropped, no-till practices. Runoff was reduced 90 percent during the vulnerable sediment and chemical transport season of May, June, and July. Annual flume-measured sediment decreased from 26.26 t (metric tons)/ha (11.71 tons/acre) with conventional tillage to 0.13 t/ha (0.06 ton/acre) with no-tillage. Soil loss values associated with no-tillage show that crop row direction is not important when no-tilling is accom-panied with grassed waterways in the Southern Piedmont. Barley and grain sorghum both produced 15.43 t/ha (6.88 tons/acre) of grain during the no-till period. Annual erosion, estimated by the Wischmeier-Smith erosion equation (WSEE), was 71.23 t/ha (31.80 tons/acre) and 1.30 t/ha (0.58 ton/acre) for conventional and no-till, respectively.