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为了探求在施加直流电场力作用下土壤电阻率的变化过程,以含有盐分的风沙土为供试材料,应用四电极法监测了在施加不同直流电压下土壤电阻率的动态变化过程。结果表明:在不同电压作用下土壤电阻率均具有明显的阶段性波动变化特征,通电10 h以前电阻率处于微小降低过程;10 h以后经过急剧递增后逐渐降低,并伴随着土壤温度的急剧增大,不同电压处理间差异明显。连续通电30 h后土壤中钠离子在阴极0~4 cm范围内富集,氯离子在阳极0~1 cm范围内富集;土壤p H在阳极附近下降约5个单位,在阴极上升约2.4个单位,两极相差7.2个单位,并在土柱断面形成了明显的碱性离子迁移带和酸性离子迁移带,阴、阳极附近电导率明显升高。研究认为,在外加电场力作用下土壤电阻率发生极为敏感的时空变化过程,通电不同阶段外加电场力对土壤溶液中活性离子和土壤颗粒吸附态离子的作用存在着阶段性特征。在用电动法改良盐渍化土壤时,选取适度的外加电压和通电时间是实现清除土壤活性离子和土壤潜性离子的重要条件,土壤p H和电阻率敏感的时空变化体现着土壤阴阳离子的异向迁移与空间分布过程。
In order to explore the process of soil resistivity change under the action of DC electric field, the sandy soil with salt content was used as the test material. The four-electrode method was used to monitor the dynamic process of soil resistivity under different DC voltages. The results show that the soil resistivity under different voltage has the characteristics of obvious periodic fluctuation. The resistivity is in a slight decrease process before 10 h of electrification. After 10 h, the resistivity decreases sharply and increases sharply with the increase of soil temperature Large, different voltage processing differences between the obvious. After 30 hours of continuous electrification, sodium in the soil was enriched in the range of 0-4 cm in the cathode and chloride was enriched in the range of 0-1 cm in the anode. Soil pH decreased about 5 units in the anode and about 2.4 in the cathode A unit, the difference between the two poles 7.2 units, and in the soil column section formed obvious alkaline ion transport zone and acidic ion transport zone, the anodic and cathodic conductivity increased significantly. It is considered that the soil resistivity under the action of applied electric field force is very sensitive to the temporal and spatial variation. The effect of applied electric field force on the ions adsorbed by the active ions and soil particles in soil solution exists in different stages. When using electric method to improve salinized soils, it is an important condition to remove soil active ions and soil potential ions by selecting appropriate applied voltage and time. Soil-pH and resistivity-sensitive spatio-temporal changes reflect the positive and negative ions Heterogeneous migration and spatial distribution process.