Effects of Straw Input on the Yield and Water-Use Efficiency of Spring Maize in Film-Mulched Farmland

To provide a theoretical basis for the sustainable application of autumn mulching technology, we examined the effects of straw input on spring maize yield and water-use efficiency in film-mulched farmland. Based on the positioning tests of different mulching methods conducted in 2013, non-mulching (NM), spring mulching (SM), autumn mulching (AM), and autumn mulching combined with the return of straw (AMS) were selected in western Liaoning from 2018 to 2021. Spring maize yield, yield component factors, soil water content, and water-use efficiency under the four treatments were assessed. In each year, the AMS treatment significantly increased the maize yield, which was 48.22%, 9.33%, 30.66%, and 9.92%, and 11.78%, 7.71%, 12.86%, and 4.77% higher than that obtained after the SM and AM treatments, respectively. However, the harvest index was not significantly improved by AMS. AMS treatment significantly improved the precipitation utilization rate in all assessed years. Moreover, the crop water consumption was significantly increased by AMS treatment. Compared with the NM treatment, water-use efficiencies for economic and biological yield were also significantly improved. Thus, autumn mulching combined with straw-returning technology is an effective technical measure for improve spring maize yield and water-use efficiency in semi-arid areas of western Liaoning.