Understanding variability in texture and acidity among sandy soils in Cambodia

摘要

Sandy soils occupy a large proportion of the Cambodian landscape, and improved understanding of these soils is critically important to support agricultural development. This study aims to identify variability in soil particle size distributions and acidity among sandy soils from different parts of southern and eastern Cambodia. Soil samples were collected from different layers at 8 sites within 4 study provinces and analysed for particle size distribution, soil pH and exchangeable Al. Clay and silt were minor fractions and comprised similar amounts at most sites. Clay fractions generally increased at about 1 m depth. Soils at a site close to the beach and sites nearby coarse grained granite mountains contained very high percentages of coarse sand (up to 87 %). At other sites, fine sands were dominant fractions. Very low pH_(CAcL_2) values (< 4) in whole profiles were found at 2 sites in the coastal area, close to the beach and sandstone mountain and at one site in eastern Cambodia. Highest whole profile exchangeable Al (0.44-1.13 cmol/kg) were seen at a site close to sandstone mountain and a site in eastern area.