Effects of ridge-furrow mulching system with supplementary irrigation on soil respiration in winter wheat fields under different rainfall conditions

Abstract

Developing an ecologically friendly supplementary irrigation method is vitally important for improving wheat productivity in terms of reduced water usage and high yields in semiarid areas. In this study, we explored the effects of the ridge-furrow mulching system (RF) with supplementary irrigation on soil respiration in winter wheat fields under different rainfall conditions. Three rainfall conditions were simulated (heavy rainfall =275 mm, normal rainfall =200 mm, and light rainfall =125 mm) and four irrigation treatments (150, 75, 37.5, and 0 mm) were examined during the growth period for winter wheat. A traditional flat (TF) planting was used as the control. The results obtained after three years (October 2015 to June 2018) showed that there was no significant difference in the soil respiration rate between RF and TF under 200 mm and 275 mm rainfall in the winter wheat growth period. Under rainfall at 125 mm, the respiration rate using RF with the same irrigation was significantly increased by 5.31–23.38% compared with that using TF, where the differences among treatments were significant, except for that with irrigation at 150 mm. Under rainfall at 275, 200, and 125 mm, the coefficients of determination for the effects of the soil temperature and water content on soil respiration were lower with RF than TF. The coefficients of determination also tended to increase as the amounts of rainfall and supplementary irrigation decreased. Therefore, to reduce the impact of supplementary irrigation under climate warming, we conclude that the P1R75, P2R150 and P3R150 treatments are suitable ecologically friendly supplementary irrigation method for reducing water usage in semiarid areas.