Soil & Tillage Research
Zhenghong Yu
Surface charges can produce strong electric field around soil particles, and profoundly influence soil water movement. The influence of soil electric field on water transportin soil column with a permanently charged soil was studied. It was found that soil electric field influences soil water transport by affecting: (1) the electrostatic forces between the electric field and water molecule dipole; and (2) soil water conductivity through controlling stability of soil aggregates. When soil electric field was high, soil aggregates were broken and soil electric field influenced soil water transport through its effect on the interaction forces between water dipole and the electric field. Conversely, when soil electric field was low, the effect of soil electric field on soil water transport was mainly through its influence on soil aggregate stability. The surface potential of 153 mV for the soil was the critical potential, below this potential, the influence of soil electric field on soil aggregate stability was the main mechanism affecting soil water transport; and above this potential, the effect of soil electric field on the interaction forces between water dipole and the electric field was the main influence on soil water transport. This study suggests that it might be possible to regulate soil water transport by adjusting soil electric field using electrolytes.
