Oil palm cultivation enhances soil pH, electrical conductivity, concentrations of exchangeable calcium, magnesium, and available sulfur and soil organic carbon content

Abstract

The land area under oil palm (Elaeis guineensis Jacq.) cultivation (OPC) is increasing in different parts of world. Assessment of the soil parameters of oil palm plantations (OPP) is essential to judge the sustainability of land use for maintaining soil fertility and avoiding land degradation. The effects of OPC in India on soil parameters are poorly understood. Therefore, we evaluated the impact of OPC over the years (by considering oil palm plantations of 6, 12, and 18 years age) on soil properties, nutrient availability, soil organic carbon (SOC) pools, and SOC stock in comparison with those parameters in adjacent fallow land (FL) of southern India. Soils of OPP showed enhanced soil pH value, electrical conductivity, the concentrations of exchangeable calcium and magnesium and available sulfur, and SOC content in 0–20, 20–40, and 40–60 cm depths of soil compared with those parameters in FL. Available phosphorus concentration in soil increased with plantation age revealing the need for rational phosphorus management. However, the concentration of available nitrogen, potassium, exchangeable calcium and magnesium, and available sulfur and boron did not change with plantation age. The contents of SOC and very labile carbon were higher in surface soil layers of OPP than that in FL. Oil palm cultivation led to 20, 18, and 45% enhancement in SOC stock in 6, 12, and 18 years‐old OPP, respectively, compared with SOC stock in FL indicating C sequestration due to OPC. The very labile and less labile C stock in FL, 6 and 12 years‐old OPP were similar, whereas the values of these parameters were higher in 18 years‐old OPP. Positive correlation (p < .01) of SOC with very labile, labile, and less labile carbon pools indicated their inter‐relatedness. This information will be utilized in devising rational nutrient management options for the existing as well as ensuing OPP due to variations in soil properties and available nutrients.