Soil water storage and maize (Zea mays L.) yield under straw return and tillage practices

Abstract Incorporating returned straw with tillage practices during the fallow period may be crucial for yield increase of dryland maize ( Zea mays L.) by improving soil water storage. Field experiments were conducted over 3 yr (2016–2019) to investigate the effects of four treatments (CK, no‐till with crushed straw left on the ground; RT, rotary tillage with crushed straw mixed into the 0‐to‐20‐cm soil layer; DP, deep ploughing with crushed straw mixed into the 30‐to‐35‐cm soil layer; SM, no‐till with whole straw mulched on the surface) on soil water storage, yield and its components, and water use efficiency (WUE) of dryland maize in northern China. Compared with CK, the yield of RT, DP, and SM treatments increased by 2.3 to 68.3, 22.8 to 126.1% and 9.3 to 119.8%, respectively, during the 3 yr. The most significant increase was obtained in the drier year of 2019, though yields were lowest overall that year. The DP treatment had greater water storage in the upper soil layer (0–100 cm) in all 3 yr, followed by SM and RT. The average increment of precipitation use efficiency and WUE under RT, DP, and SM was 25.4, 58.6, and 48.6 and 20.7, 31.6, and 29.9%, respectively. The results indicated that numerically higher yield components and yields of dryland maize were observed upon DP and SM. Thus, these two practices (DP and SM) could be suitable field management choices to promote water storage and production of dryland maize in the northern China.