Effects of tillage and straw mulching on the crop productivity and hydrothermal resource utilization in a winter wheat-summer maize rotation system

Abstract

Tillage combined with straw mulching is an effective water-saving agricultural strategy in eastern Central China. A two-year field experiment with four treatments, including conventional tillage (CT), conventional tillage with straw mulching (CT+S), no-tillage (NT) and no-tillage with straw mulching (NT+S), was conducted on semihydromorphic soil. The objective was to investigate how tillage with straw mulching affected the soil temperature, water consumption, photosynthetic rate (Pn), grain yield, soil temperature use efficiency (TUE) and water productivity (WP) in a winter wheat-summer maize rotation system. The results indicated that straw mulching tended to increase the soil temperature before the wheat regreening stage and decrease the soil temperature during the following wheat growing season and throughout the maize growing season. Compared with CT, the soil effective accumulated temperature (EAT) under the NT+S treatment significantly decreased by 4.8% but the annual ET increased by 4.3% in the winter wheat–summer maize rotation system. The Pn and transpiration rate (Tr) at the anthesis stage of wheat under the NT+S treatment increased by 15.2% and 15.6%, respectively, and the leaf water use efficiency (LWUE) during the growing season of maize increased by 11.3% as compared with that under CT treatment. Wheat yields decreased in the order of NT+S, NT, CT and CT+S during both experimental years, and the average yield of maize under the NT+S treatment increased by 27.2% compared with that under CT. Additionally, WP values under the NT+S treatment during both the wheat and maize seasons were 7.0% and 21.8% higher than those of the CT treatment (p < 0.05), respectively. The annual yield, TUE and WP values under the NT+S treatment were much higher than those under the other treatments. Therefore, NT+S treatment has a positive effect on yield and hydrothermal resource utilization in semihydromorphic soil in eastern Central China.