Effects of mulched drip irrigation on phenological development of spring maize

Based on a field experiment conducted at a fixed site over eight years (2015~2022) in arid northwest China, this study quantified how mulched drip irrigation (DI) and mulched border irrigation (BI) alter spring maize phenology through changes in canopy temperature, soil temperature and soil water content. Compared with BI, DI raised the average canopy temperature by 0.72 °C, soil temperature by 1.0 °C and soil water content by 3.4%. The improved microenvironment significantly shortened the seedling and maturity stages. The total growing season declined by 11.44 d on average. The durations of the jointing, heading and filling stages were unaffected. Multiple regression that included the interaction between temperature and water revealed a significant positive interaction between canopy temperature and soil water content. A larger difference in soil water amplified the advance of crop development driven by temperature and partly offset the shortening of the growth period caused by warming. Over the eight years, DI increased average biomass, grain yield and water use efficiency by 4.96%, 11.78% and 27.57%, respectively. Overall, DI optimizes field hydrothermal conditions, advances maize phenology and improves crop productivity. It offers a feasible irrigation strategy for saving water in arid agricultural regions.