Profile description, properties, and classification of paddy soils at different topographical positions in Surin Province, Thailand(Pedon paper)

抄録

Surin Province has long been used to cultivate Thai jasmine rice, yield of which is strongly affected by topographical positions of paddy fields. The present study was conducted to investigate the characteristics of Surin paddy soils at high and low topographical positions in Tha Tum and Chom Phra districts in Surin Province. Differences in nutrient leaching and accumulation according to water stagnation and drainage at each topographical position were observed. Soils in the study area had a sandy texture, high acidity, low nutrient levels, and low water holding capacity, all of which were more serious at high topographical positions. Soils at low topographical positions were less acidified, having pH values of ≥5.8 at lower horizons and one soil showed incipient soil salinization. The difference between these soils at high and low elevations in both districts indicated that soils at high positions are at risk of nutrient and water deficiency because of leaching, while those at low positions have a risk of soil salinization.