Changes in Soil Physical Properties Owing to Soil Reduction Treated with Electrokinetic Treatment

Abstract

Increasing soil water content due to soil reduction is generally confirmed in rice paddy soils after flood irrigation or in littoral sediments with high organic matter content. This could be caused by soil aggregates during the reduction process through biological and electrostatic phenomena. In the literature, changes in liquid and plastic limits owing to soil reduction treated with electrokinetic treatment (ET) have been reported; however, there was no report relating to changes in other soil physical properties, such as grain size distribution (GSD) and water-holding capacity (WHC). Thus, this study aimed to examine changes in soil physical properties caused by soil reduction treated with ET. Changes in GSD, hydraulic conductivity, and WHC were examined in laboratory experiments to understand soil aggregates due to soil reduction. During ET application, a decrease in electrical conductivity was observed, indicating the cohesion of ions (soil aggregate). This resulted in increases in the percentage of particles ranging from 0.075-0.212 mm, hydraulic conductivity, and WHC. However, particle dispersion occurred when the electrical current was high (10 mA), resulting in a significant decrease in hydraulic conductivity and WHC. Therefore, it can be said that soil aggregates can develop electrostatically. Thus, ET can be used for developing soil aggregate.