Influence of Tropical Climate Parameters on Properties of Acid Sulfate Soils for Sustainable Oil Palm Cultivation

Abstract

To promote effective oil palm plantation and environmental sustainability, this research assessed influence of climatic parameters on physicochemical properties of Thai acid sulfate soils (ASSs). ASSs under oil palm planting areas (Topsoil: Ap, Subsoil-1: Ap-60 cm, Subsoil-2: 60–100 cm, and Rootzone: sum of the three depth levels) and historical climate data in tropical savanna and tropical monsoon were investigated. Stepwise approach of multiple regression analysis from component defining variable of principal component analysis revealed that, in tropical savanna, daily solar radiation influenced clay content (p<0.05) in Topsoil, cation exchange capacity (p<0.05) in Subsoil-1, soil pH by water (p<0.01) in Subsoil-2, and silt content (p<0.001) in Rootzone. In tropical monsoon, daily solar radiation influenced exchangeable magnesium (p<0.01) in Subsoil-2, and exchangeable sodium (p<0.01) and silt content (p<0.01) in Rootzone. We concluded that daily solar radiation is the most influential climatic parameter on soil properties due to the transport of heat in soils, whereas particle size distribution is mostly influenced by climatic parameters due to their clay and silt fractions. OPP in ASSs under these climates should include management of water usage by using raised beds with irrigation canals, considering the rooting depth and depth of acidic horizon before applying fertilizer or amendment and liming along with integrated organic material management to raise soil pH.