咸水非充分灌溉小麦根区土壤水盐运移规律及调控机理研究

Because of the shortage of freshwater resources, saline irrigation is required in arid northwest area of China. When saline water is applied with non-sufficient irrigation, water and salt environment in crop root zone will be changed due to the impact of water-salt interaction effects on crop growth and soil properties. Therefore, it is very important to carry out researches on the regulation and controlling mechanism of root zone soil water-salt transport under nonsufficient saline irrigation for wheat. Based on field irrigation experiments, laboratorial simulation experiments and mathematical simulation models, the effect of salinity on soil hydraulic characteristics and root water uptake will be studied, and the impact process and mechanism of the nonsufficient saline irrigation on root zone water-salt transport will be revealed in this project. The relationship between yield, water use efficiency and soil water and salt content will be quantitative analyzed to establish the crop water-salt production fuction under combined water and salt stress. Considering water-salt interaction effects on root zone water and salt content and water use efficiency of wheat, root zone salinity control model based on soil water-salt dynamics theory will be established to control root zone water and salinity reasonably. The research will provide a scientific basis and technical support for efficient use of saline water for agriculture in arid northwest areas.

由于淡水资源短缺，咸水灌溉在我国西北旱区的应用势在必行。咸水灌溉与非充分灌溉相结合时，由于水盐交互作用对作物生长和土壤性质产生影响，作物根区的水盐环境将发生改变，因此开展咸水非充分灌溉根区土壤水盐运移规律及调控机理研究具有重要意义。本申请项目拟通过开展小麦田间灌溉试验和室内模拟实验，采用数值模拟等手段，研究盐分对土壤水力特性和根系吸水速率的影响，揭示咸水非充分灌溉对根区土壤水盐运移的影响过程和机理；定量分析产量、水分利用效率与根区土壤含水量、含盐量的关系，建立水盐联合作用下的水盐生产函数；考虑水盐交互作用对根区水、盐分和小麦水分利用效率的影响，建立基于土壤水盐动力学过程的根区水盐调控模型，合理调控根区水盐环境。本研究可为西北干旱地区咸水资源高效利用提供科学依据与技术支持。

本项目围绕作物水盐响应关系及根区土壤水盐调控机理等关键问题，开展了田间灌溉试验，定量研究了不同灌水量和不同灌水矿化度对小麦生长、耗水特性的影响；初步建立了水盐联合作用下小麦的根系吸水模型；结合数值模型，揭示了不同上边界条件对根区水盐运移的影响机理，合理调控农田土壤水分、盐分迁移过程，确定了当地春小麦和春玉米节水、高效、控盐的灌溉制度。研究结果对于促进劣质水土资源的高效利用、保证干旱地区节水农业的可持续发展具有重要的科学意义和应用前景。上述研究内容目前已经发表SCI论文1篇，EI论文2篇，国内核心期刊收录论文2篇，出版专著1部，培养硕士研究生3人。