Reclamation of Saline Soil in Northeastern Thailand Using a Solar-Powered Pump to Control Groundwater Levels

A low agricultural productivity in northeastern Thailand primarily results from saline soils predominately distributed throughout the region. We proposed a remediation technique for the saline soil by using a solar-powered pump and subsurface drainage system (SPSD system) . This study was conducted in Khon Kaen Province, northeastern Thailand. The SPSD system could lower the groundwater levels and subsequently reduce the capillary rise of saline groundwater toward the soil surface. The SPSD system first collects excess groundwater through the drainage pipes connected to a water tank under the ground. Groundwater collected in the tank is automatically discharged out by the solar-powered pump. The electrical conductivity of groundwater (ECw) measured in the area where the SPSD system was installed suggested that lowering of the groundwater levels using the SPSD system could enhance salt leaching from the soil profile by rainfall. The electrical conductivity of soils at the sampling point where the SPSD system was installed was lower than those obtained from the same soil profile at the control sites. Consequently, this study suggests that lowering groundwater levels using the SPSD system may be an effective means for reducing salinity degree of soil and groundwater in northeastern Thailand.