利用探地雷达低频天线监测滴灌棉田盐渍化土壤盐分迁移研究

盐渍化问题严重制约着新疆地区农业经济的发展,而掌握土壤盐分迁移情况是防治土壤盐渍化的前提.为更好地了解滴灌棉田盐渍化土壤盐分的迁移情况,本文选用一典型滴灌棉田为研究对象,采用探地雷达低频天线(250 MHz)进行土壤剖面的探测,由探地雷达图像中的信息,推测土壤盐分在垂直方向上的迁移情况,再用土壤剖面水盐动态、盐分通量变...

Salt Transfer of Salinized Soil in a Drip Irrigation Cotton Field Investigated by Using GPR Low Frequency Antenna

The natural objective factors of low rainfall, high evaporation, high salt discharge, and high groundwater level in Xinjiang make the soil salinization in the region extremely prominent. Soil salinization is a crucial factor not limited to resource and ecological problems but also regional agricultural and economic development. Therefore, the study of salt transport mechanisms in saline soils will help prevent secondary soil salinization and ensure saline soils' sustainable development. As a near-ground remote sensing technology, ground penetrating radar (GPR) can investigate soil salt migration quickly and effectively, and this technology is widely used in agricultural soil surveys. Herein, a typical drip-irrigated cotton field was selected as the research object, and the soil profile was probed using a low-frequency antenna (250 MHz). The information in the GPR images was verified with actual observations such as water-salt dynamics and salt flux changes in the soil profile, and the following conclusions were drawn. (1) Where the gradients of soil salinity concentration were obvious, the radar images of GPR could be divided into the salt accumulation zone, the vadose zone, and the evaporation surface according to the actual situation. (2) The actual migration of soil salts was overall transported upward and then downward in the whole research phase. Through verifying the water-salt dynamics and salt fluxes, it was identified that the evaporation surface changes in the GRP images were consistent with the actual salt transport. Therefore, it was feasible to use GPR low-frequency antennas to monitor the migration of soil salts in the vertical direction and the changes of evaporation surfaces in drip-irrigated cotton fields to characterize the overall transport of soil salts. In summary, a new idea for the prevention and control of soil salinization caused by salt migration is provided by the fast and nondestructive identification of evaporation surfaces using GPR low-frequency antennas.