Optimizing Drip-irrigation Schedule of Maize in Xinjiang Using the CERES-Maize Model

Abstract

【Objective】 Water scarcity is the bottleneck constraining food production in Xinjiang province of China, and optimizing agricultural water usage is hence critical to developing sustainable agriculture in this region. The purpose of this paper is to propose a method to optimize drip-irrigation scheduling for mulched maize fields. 【Method】 The optimization is based on the DSSAT-CERES-Maize model parameters; growth and yield of the maize measured under different irrigation levels in 2020 was used to calibrate the model. Based on meteorological data measured from 1979 to 2017 in the studied region, we compared 14 different irrigation schemes in typical years and selected the optimal irrigation schedule for maize growth under mulched drip irrigation. 【Result】 Comparison showed that the leaf area index, dry matter weight and the yield simulated by the model for different irrigation levels correctly reproduced what were measured. We found that the sensitivity of the maize to water stress varied with season, and based on the degree of the sensitivity, the growth stages can be ranked as follows in a descending order: tasseling period>jointing period>filling period. Considering both yield and water use efficiency, the optimal irrigation amount in the tasseling period should be 80, 180 mm and 120 mm for dry, normal and wet years, respectively. The irrigation amount should be 120 mm in the filling stage and 60 mm for other stages. The yield under the optimized irrigation schedule accounted for 99.53%, 97.51% and 98.45% of the highest yield in dry, normal and wet years, respectively. 【Conclusion】 The CERES-Maize model is reliable. It can be used not only to optimize drip-irrigation schedule of maize in Xinjiang but also has an implication for optimizing irrigation of other crops in Xinjiang and beyond.

Keywords

• drip irrigation
• maize
• ceres-maize model
• irrigation schedule
• yield
• water use efficiency