Cereal Research Communications | 2021
Effects of straw returning on soil moisture and maize yield in semi-humid area
Abstract
The purpose of this study was to control the effects of different tillage and straw returning methods on the temporal and spatial changes of soil moisture, photosynthetic characteristics of maize leaves, maize yield and water use efficiency, and to provide the basis for the cultivation mode of maize yield increase, water efficiency and soil sustainable utilization in semi-humid area. The spatial and temporal changes of soil moisture, leaf photosynthetic characteristics, maize yield and water use efficiency (WUE) were studied under four treatments, rotary cultivation and ridging of straws (CK), full amount and deep turning of straw back to the field (SP), no till straw smashed in full amount, covering and returning to the field (SC) and straw mulching and mechanical deep loosening (SS). The spatial and temporal dynamics of soil water storage showed a single peak curve in 2018 and a double peak curve in 2019. Soil water storage increased with the increase of soil depth. The soil water storage of SC and SS treatments were significantly higher than that of SP and CK treatments in the range of 0–60\xa0cm. The net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci) and transpiration rate (Tr) of maize leaves of SP, SC and SS treatments were significantly increased compared with CK treatment in 2018 and 2019, the Pn, Gs, Ci and Tr of SP and SC treatments were significantly lower than those of SS treatment. The stomatal limitation percentage (Ls) of SS treatment was significantly decreased compared with CK, SP and SC treatments. The yield of SS treatment increased by 13.88% and 14.82% in 2018 and 2019, SP treatment increased by 7.59% and 9.12%, SC treatment increased by 7.42% and 8.5%, respectively, compared with CK treatment. The water use efficiency (WUE) of SS treatment increased by 13.89% and 9.80% in 2018 and 2019, SP treatment increased by 6.36% and 6.02%, SC treatment increased by 5.77% and 3.92%, respectively. Straw returning reduced soil water evaporation, increased soil water storage, promoted maize photosynthesis and dry matter accumulation, and significantly increased maize yield and water use efficiency. Straw mulching subsoiling is more suitable for drought resistance, yield increase and water efficient cultivation technology mode of maize in rain fed agricultural area.