Rehabilitation of Salt Affected Soils with Chemical Geo-Textile in Northeast Thailand

Salt accumulation occurred due to capillary water rise from salt groundwater is one of the major problems in Northeast Thailand. The salt accumulation is causing a serious farming problem. So, this study dealt with the rehabilitation strategy on salt affected soils for sustainable agriculture in Phra Yun, Northeast Thailand. Application of chemical geo-textile was investigated in the laboratory experiment using the soil column. The results indicated that chemical geo-textile could intercept the capillary water rise in the laboratory experiment. Based on the results of soil column experiment, chemical geo-textile was installed in the salt affected fields of Phra Yun. The field experimental results showed that EC1:5 values in surface soils of the ridges installed the chemical geo-textile did not decrease, as sodium components existing in surface soils could not be washed out by leaching with rainfall. Therefore, leaching experiment was conducted to discuss the effective leaching measures. Through the leaching experiment, it became clear that soil permeability improvement is indispensable for washing sodium components out. Also, the experimental results showed that EC1:5 values were reduced far below the expected crop tolerance level if applying enough volume of water as same in water height as surface soil depth. In addition, the higher mixing ratio with gravel in surface soils showed the higher effectiveness for reducing EC1:5 values with leaching.