Tri Ton district of An Giang province is located in the South West direction, Mekong delta with the natural area is almost mountainous, water resource is very limited for agricultural production. Cultivation is mainly influenced by rainfed. The results of 3 representative study locations with 120 soil samples and field investigation of 60 farmer households in the area showed that the coarse-medium soil texture is dominant in the study area
soil bulk density varies from 1.25 g/cm3 to 1.73 g/cm3
soil particle density changes from 2.16 g/cm3 to 2.65 g/cm3, soil porosity is in the range of 21.00 percent - 46.66 percent, subsoil horizons trend to be compacted. Poor soil structure quotient varies from 19.82 to 68.81, it reaches highest value at Co To village. Soil organic matter and soil texture are two main factors influencing to the soil structural development. Available soil water holding capacity in situ within 100 cm from the topsoil of 3 study locations differs from 33.7 mm to 220.6 mm and it is lower than that of other soils in the delta. Available soil water shortage in the dry season becomes a big problem and available soil water content of topsoil horizon changes from 9.79 mm to 27.15 mm. Consequently, the weathered soils have a poor physical soil fertility. Based on the obtained results, beside strenthening agricultural extension works, contructing the irrigation system for upland area, applying organic and balanced inorganic fertilizer are the important activities and essential practices should be done to improve the natural soil fertility for sustainable agricultural production in Bay Nui region, An Giang province.