Monitoring of salt movement in one year round of a serious saline soil Case study: Ban Muang Pia, Ban Phai district, Khon Kaen province.

Abstract

This study was done at Ban Mueang Phia, Ban Phai district, Khon Kaen province. The objectives of this study were to monitor both the upwardly and downwardly vertical movements of salt in one year, and to study the relationships between saline level and soil moisture content, including the water table level. The site was divided into 3 zones (upland, middle-land and lowland). Soil samples were collected by the soil auger at 10 cm intervals from the soil surface (0-10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, 90-100 cm) along with water table level measurements in the piezometer nests. The soil samples were analyzed in the laboratory for EC and soil moisture content. The results showed that the average EC of upland, middle-land and lowland was 0.78, 1.62 and 17.06 dS / m, respectively. The average water table level at upland, middle-land and lowland fields was 3.52, 2.49 and 0.53 m, respectively. The average soil moisture content at upland, middle-land and lowland was 6.52, 20.24 and 14.95%, respectively. These evidently showed that the upward and downward movements of salt were related with season and water table level. Salts were dissolved by rainwater and moved downward during the rainy season. Conversely, the upward movement of salt was found during the dry season due to capillary rise, causing noticeable salt patches on the soil surface. Moreover, the soil moisture content was related with soil texture and season.