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采用亮蓝FCF染色示踪剂,研究膜下滴灌条件的水盐运移规律;分别在灌溉前、灌溉中和灌溉后等不同时间段共开挖13个时刻的剖面,观察膜下滴灌湿润面的运移情况;以10cm间隔的网格,用MP406土壤水分探测器原位测定3120个点的土壤体积含水率,同时取1430份土样,利用1:5土水比浸提法测定土壤盐分;并利用WATCHDOG气象站监测研究区气象要素.结果表明:染色示踪能直观表征土壤水盐运动轨迹;膜下滴灌条件下,垂直滴灌带方向土壤水流呈点源入渗特征、沿滴灌带方向近似呈线源入渗特征;现行灌溉模式下,壤质砂土湿润锋横向运移速率约为8cm/h;滴灌对滴头附近土体有一定洗盐效果,未覆膜区域地表土体出现盐分积累;灌水时间越长,湿润锋越深,横向扩展速率接近无作物小区(8cm/h);从土壤水合理利用角度考虑,满足研究区一膜一带四行的种植模式和土质的单次合理灌水量应为29.4～69.8mm.
The light blue FCF staining tracer was used to study the movement of water and salt under drip irrigation conditions. The sections were excavated at different time periods before, during and after irrigation respectively. The wetting surface The soil moisture content of 3120 sites was determined by in-situ MP406 soil moisture detector at 10cm intervals. At the same time, 1430 soil samples were taken, and the soil salinity ; And the WATCHDOG meteorological station was used to monitor the meteorological elements in the study area. The results showed that: the stain tracing can directly characterize the movement of soil water and salt; under drip irrigation under mulch, the soil water flow in vertical drip irrigation zone showed point source infiltration characteristics, Which is similar to the characteristics of source-infiltration. Under the current irrigation mode, the horizontal transport rate of loam front is about 8cm / h. Drip irrigation has a salt-washing effect on the soil near drippers, Salt accumulation; the longer the irrigation time, the deeper the wetting front, and the lateral expansion rate is close to the no-crop area (8cm / h); From the perspective of rational use of soil water, the planting pattern of one line, Reasonable irrigation volume should be 29.4 ~ 69.8mm.