塔里木河下游农田根灌与滴灌条件下土壤蒸发试验研究

Experimental Study on the Soil Evaporation under Root-zone Irrigation and Drip Irrigation in Agricultural System in the Downstream Part of Tarim river

土壤蒸发是灌溉水分无效损失的部分,为定量分析根灌较滴灌的技术优势,于塔里木河下游33团红枣生态经济林中开展根灌与滴灌对比试验研究。试验中采用微型蒸渗仪测定土壤蒸发量,采用烘干法测定土壤含水率,采用主成分回归分析法对土壤蒸发量的各影响因素进行耦合关系分析研究。研究结果表明,土壤蒸发受到气象因素和灌溉方式的双重影响,且同等气象条件下,根灌技术,相对于滴灌而言,可有效的缓解表层土壤含水率的增加量,进而缓解灌溉水分由土壤蒸发引起的损耗量。由此可见,根灌由于避免灌溉表层土壤而灌溉一定深度的土壤层,较滴灌可进一步提高灌溉水资源利用效率,在水资源供需矛盾突出的干旱区具有广阔的应用前景。

To quantify the technical advantage of root-zone irrigation （RZI） compared with drip irrigation （DI）, the experimental re- search on RZI and DI was conducted in the eco-eeonomical forests of red jujube in Crop 33 in the downstream part of Tarim river. The Micro-Lysimeters （MLS） was utilized to measure the soil evaporation, the over drying method was adopted to determine the soil water content and the principal-component ~ regression method was adopted to analyze the coupled relation among the various ~ac- tors which influence soil evaporation. The results showed that soil evaporation was influenced by meteorological factor and irrigation style. Compared with DI, with the same meteorological conditions, RZI can effectively soften the increment of soil water content in the surface soil layer. Thus, RZI can reduce the water-loss of irrigation water by soil evaporation. So, RZI, compared with DI, which adopts the irrigation on some depth of soil layer rather than the irrigation on the surface soil, could improve the water use efficiency of irrigation water. So, RZI could be widely applied in the arid regions with severe contradiction between supply and demand of water resources.