Residual Effect of Cover Crops and Conservation Tillage on Soil Physical Properties and Wheat Yield Grown after Direct Seeded Rice

摘要

Conservation tillage (CT) in wheat offers a pragmatic option for resolving the time and edaphic conflicts in rice–wheat cropping system (RWS). This two-year study was conducted to evaluate the residual impact of cover crops and tillage methods on soil physical properties, and growth and grain yield of wheat. The cover crops, including Egyptian clover, crimson clover, hairy vetch, alfalfa, and sweet clover, were sown in the rice field at physiological maturity stage. Before wheat planting, seedbed was prepared using conventional tillage and deep tillage or wheat was sown without tillage (zero-till) into the stubbles of previous crop. Soil physical properties i.e., soil bulk density, water holding capacity and soil organic matter were significantly improved by the cover crops. There was a considerable decrease in soil bulk density in both years i.e., 15% in 2017 and 19% in 2018 in deep tillage using Egyptian clover as a cover crop. The soil organic matter (SOM) was increased because of the incorporation of cover crops and crop residues into the soil. The SOM in the sec year (2018) increased by 8.1% than the first year (2017). Wheat planted with conventional tillage together with cover crops, especially Egyptian clover, performed better than the other two methods. In conclusion, wheat sown using conventional tillage in combination with Egyptian clover as a cover crop seemed a viable option to improve the soil properties and crop yield.