Soil properties and classification of a small-scale steep sloping field under traditional slash and burn cropping systems in Sabah, Malaysia

抄録

Slash-and-burn agriculture is a widespread practice and seen as an environmentally destructive method, but traditional slash-and-burn agriculture has been practiced for centuries without detailed evaluation of its sustainability. To understand the current status of soil profile characteristics and fertility, we assessed two soil profiles within a small sloping upland field in Sabah, Malaysia. This paper presents the results of on-site soil profile assessment as well as clay mineralogy and soil physico-chemical evaluations. We observed two different soil groups of Acrisols and Luvisols with varying soil texture and clay mineralogy within the field. Total C content and cation exchange capacity were high under concave micro-topography. With no external fertilizer inputs, this agricultural system appeared to replenish adequate or sometimes slightly excessive amount of P, K, Mg, and Ca to the topsoil. Subsoil acidity and high exchangeable Al concentration appeared problematic for crop production and the soil profile under convex micro-topography showing excessively high Al concentration. In conclusion, the traditional slash-and-burn agriculture resulted in C and nutrient rich soil profile but it depended on the types of parent materials and micro-topography. Further studies are needed with larger sample size and geospatial analysis to fully understand the sustainability of the agricultural system.