Rapid expansion of cropping is occurring in Cambodia outside of the areas traditionally used for lowland rice. Soils and landscapes in these areas are poorly described at present, hampering efforts to develop sustainable soils management and crop production systems. In the present project, soils and landscapes in Banan district Battambag province were investigated by a semi-detailed soil survey. A soil-landscape map was developed for the district in which 14 units were recognised. The main soil-landscape units in order of their capability for non-rice cropping were: Kein Svay an alluvial loam along the Sangke River, the brown phase of Toul Samroung Soil group on gently undulating plains and a calcareous phase of the Kompong Siem Soil group that develops on sloping land surrounding limestone hills. All soils are prone to waterlogging during periods of heavy rain. Otherwise the Kein Svay has few chemical or physical limitations for non-rice crops. Toul Samroung soil may be strongly acid, and contains high extractable manganese levels. The Kompong Siem calcareous phase is a shallow to moderately deep clay soil that forms deep cracks when dry. It is prone to stickiness when wet and hardness when dry. Severe iron chlorosis on this alkaline soil is a serious limitation for many crops. Crop performance on Kompong Siem calcareous phase was poor compared to elsewhere in Cambodia on Kompong Siem soil on basalt, and compared to Kein Svay and Toul Samroung soils in the same district. Properties of additional soils in the south of Banan district were not determined due to access limitations
