Multi-growth stage regulated deficit irrigation improves maize water productivity in an arid region of China

Improving crop water productivity (WP) in the face of drought conditions and optimizing water allocation for irrigated crops are critical steps toward mitigating the challenges associated with agricultural water use. To investigate the effects of regulated deficit irrigation (RDI) at different growth stages on maize yield and WP, a 4-year field experiment was conducted on spring maize under film drip irrigation from 2016 to 2019 in an arid region of northwest China. RDI significantly reduced plant height, leaf area index (LAI) and dry matter accumulation (DM). Notably, the moderate RDI treatment, denoted as 65/80ET (before and after "/" represent the irrigation volume relative to fully irrigation in the late vegetative and reproductive growth stages, respectively), reduced crop water consumption. This reduction was accompanied by the maintenance of relatively high grain yield and a significant increase in the harvest index, thereby resulting in a marked improvement in WP. In summary, the results of this study indicate that the 65/80ET treatment can effectively stabilize yield while improving efficiency. As such, it can be considered a viable RDI strategy for achieving water-saving, yield stability and enhanced efficiency in maize production.