Liquid Mulch Can Improve the Yield and Water Use Efficiency of Summer Maize ( Zea mays L.) Planted in Furrow‐Ridge Rainwater Harvesting Systems

The frequent occurrence of drought is an important factor restricting economic as well as sustainable agricultural development. Therefore, to address the issue of seasonal drought during summer in dry semi‐humid areas of Guanzhong Plain, a biodegradable liquid film is used to replace the plastic film for ridge–furrow rainwater harvesting in summer maize cultivation. The experiment was conducted for 2 years (2022–2023), including seven treatments, such as three ridge–furrow ratios with two different mulching materials, while flat planting is a control treatment. The results showed that ridge covering with liquid film (RFL) enhances leaf area and dry matter accumulation as well as improves soil moisture and temperature during the early growth stages of maize. However, the average dry matter accumulation of RFL at maturity stage increased by 6.92% as compared to control (CK). Additionally, the average leaf area of RFL enhanced by 4.52% and 9.06% in contrast to no mulching of soil ridges (RFS) and CK treatments, whereas RFL delayed leaf senescence at the filling stage, providing favourable conditions for high yield. Although, in 2022, the yield as well as water use efficiency (WUE) under RFL increased by 3.3% and 16.13%, than CK treatments, in 2023, they boosted by 13.92% and 20.79%, respectively. In both years, instead of drought during the early growth stages of growth, RFL enhanced both the yield and WUE of summer maize. Therefore, liquid film can be preferred rather than plastic film in dry semi‐humid areas. However, the results also indicated that the optimal ridge–furrow ratio for both yield and WUE is significantly affected by different years and climate conditions. So, further research is needed to study the yield and WUE under various rainfall patterns.