Optimizing irrigation scheduling for maize based on soil moisture threshold and water consumption intensity

Abstract

[Objective] Maize is a water-intensive crop, and its production in northwestern China heavily depends on irrigation. Optimising irrigation scheduling is hence essential to improving water use efficiency and conserving water resources. This paper proposes a method to optimise irrigation scheduling for maize cultivation in this region. [Method] Field experiments were conducted in Xinjiang using mulched drip irrigation and high-yield maize varieties (DH618 and XY335) under varying total irrigation amounts. For each irrigation-amount treatment, the experiments evaluated the suitable depth of the wetting soil layer, water consumption, yield, and water use efficiency of the crops during different growth stages. The optimal irrigation amount and scheduling were determined based on these measurements. [Result] For both varieties, the suitable depth of the wetting soil layer was 20 cm at early vegetative growth stage, and 40 cm at late vegetative growth stage, tasseling stage and milk stage. The water use efficiency of both varieties was the highest when total irrigation amount was 660 cm. The optimal irrigation scheduling for the DH618 variety was 51-70 mm in each irrigation with the total irrigation amount being 649.5 mm, while for the XY335 variety, the optimal irrigation was 39-67.5 mm in each irrigation with the total irrigation amount being 629.5 mm. [Conclusion] The proposed method, based on soil moisture thresholds and crop water consumption, provides a more scientifically grounded approach to allocate irrigation water across growth stages. It enhances water use efficiency, conserves water resources, and increases maize yield, offering a valuable strategy for sustainable irrigation management in arid regions.

Keywords

• maize
• soil moisture
• planned wetted layer
• water consumption law
• water depletion intensity