西藏高寒区低温融雪水灌溉研究进展与展望

低温融雪水是西藏高寒区的重要灌溉水源,然而由于西藏高海拔地区低压低氧、强辐射、近地层冷热交换频繁,加之地表土层薄,低温融雪水利用不当容易对作物造成寒害,为了能高效地利用低温融雪水灌溉,解决西藏高寒区的关键科学问题,依次对低温水灌溉对土壤特性的影响、低温水灌溉对作物生长的影响、西藏高寒区低温水灌溉现状等国内外研究现状进行分析,并总结出其面临的关键科学问题.研究分析表明,未来应围绕融雪水-土壤-牧草耦合界面开展研究,探求低温融雪水灌溉条件下耦合界面各要素(土壤水热、根系吸水特征、牧草生长与生理生态)之间的互作机制与联动过程,揭示融雪水灌溉条件下牧草受到寒害胁迫的作用机理,创新高寒区融雪水调控灌溉理论.作物生理与土壤水热等多学科交叉研究是降低低温融雪水灌溉危害的重要研究手段.研究结果有助于西藏高寒区提出低温融雪水合理利用模式,提升高寒区牧草产量.

Progress and prospect in research on snowmelt water irrigation affecting soil and pasture in frigid regions of Tibet

Snowmelt water is an important water source for frigid region in Tibet. However, owing to the low pressure, low oxygen, strong solar radiation, frequent heat transfer and thin soil layer, impro-per application of low-temperature snowmelt water will cause chilling injury for the pasture. The infiltration and runoff of low-temperature snowmelt water are important for agricultural water cycles, efficient water use and irrigation and it is one of landmark hydrological processes in frigid regions. Therefore, efficient use of snowmelt irrigation becomes a key scientific problem that needs to be solved in Tibet frigid regions. This article reviews the present situation of low-temperature water irrigation and the effect of low-temperature water on soil and plants in Tibet. The multi disciplinary including subjects of crop physiology, irrigation and water conservancy is the priority for reducing the hazard of low-temperature snowmelt in frigid regions of Tibet. This study is helpful to raising the reasonable utilization mode of low-temperature snowmelt water in frigid regions of Tibet and increasing the yield of pasture in frigid regions.