基于WheatSM模型的华北地区冬小麦灌溉次数与时期优化研究

Optimization of Irrigation Frequency and Timing of Winter Wheat in North China Based on WheatSM Model

摘要:

全球气候变化背景下,华北地区作为中国冬小麦主产区,种植面积扩张与水资源紧缺矛盾日益凸显,优化灌溉制度对保障小麦生产和水资源高效利用具有重要科学价值与实践意义。尽管“少量多次”灌溉可实现节水并提高资源利用效率,但在大规模农业生产实践中有限灌溉次数的优化可操作性更强。本文基于验证后的WheatSM小麦机理模型,比较分析了1988—2016年华北地区不同降水年型下灌溉次数与灌溉时期对冬小麦产量及水分利用效率的影响,明确不同气候背景下区域灌溉次数和灌溉时期优化方案。结果表明,华北地区冬小麦推荐灌溉次数为2~3次;尽管产量随灌溉水量和次数增加而上升,但3次灌溉对产量提升作用有限;以生长季平均降水量504、463 mm 2条等降水量线作为灌溉次数选择阈值,生长季降水偏少地区返青期灌1水的优势明显。研究结果可为华北地区冬小麦区域性节水高效灌溉管理提供量化依据。

Abstract:

Under the context of global climate change, the North China, as the main winter wheat production region of China, has faced an intensifying conflict between the expansion of cultivation area and severe water scarcity. Optimizing the irrigation system held great scientific and practical significance for ensuring wheat production and efficient utilization of water resources. Although the "few but frequent" irrigation could achieve water conservation and enhance resource utilization efficiency, optimizing the number of irrigation events within practical limits in large-scale agricultural production was more feasible. Based on the validated WheatSM crop model, aiming to clarify the impact of irrigation frequency and timing under different precipitation types in North China from 1988 to 2016 on winter wheat yield and water use efficiency. The results indicated that the recommended irrigation frequency for the region was 2~3 times. Although yield was increased with additional water inputs, the effect of three times irrigation was limited. Two growing-season precipitation isolines (504 mm and 463 mm) served as effective thresholds for irrigation planning. In areas with below-average seasonal precipitation, a single irrigation during the green-up stage delivered a clear yield advantage. The research result can provide quantitative guidelines for region-specific, water-saving, and efficient irrigation management in winter wheat production in the North China.