基于CERES-Maize模型的新疆滴灌玉米灌溉制度优化

【目的】研究新疆膜下滴灌玉米的灌溉制度和需水规律,为新疆玉米节水增产提供科学指导。【方法】基于2020年4个不同灌水水平下的玉米生长发育及产量数据,对DSSAT-CERES-Maize模型进行参数率定和验证,评价模型在新疆地区的适用性;利用1979―2017年气象数据,对典型年型分别设置14种灌溉方案,探究新疆膜下滴灌玉米的最优灌溉制度。【结果】利用玉米的叶面积指数、干物质量、产量的观测值对CERES-Maize模型进行参数率定和验证。叶面积指数、干物质量、产量等的模拟值和实测值都表现出了较好的一致性,模拟效果较好。通过模拟分析可得,不同年型玉米关键需水期对缺水的敏感程度大小为:抽雄期>拔节期>灌浆期。综合考虑产量和水分利用效率,枯水年、平水年、丰水年玉米抽雄期灌溉量分别为180、180、120 mm,灌浆期均灌溉120 mm,其余各生育期灌溉量都为60mm时最优。优化后灌溉制度对应的产量分别在枯水年、平水年、丰水年占对应最高产量的99.53%、97.51%、98.45%。【结论】CERES-Maize模型总体上可以应用于新疆地区滴灌玉米的研究,利用模型优化后的灌溉制度能够为新疆滴灌玉米的种植提供一定的参考依据。

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

【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.