Establishing Critical Leaf Nutrient Concentrations and Identification of Yield Limiting Nutrients for Precise Nutrient Prescriptions of Oil Palm (Elaeis guineensis Jacq) Plantations

African oil palm (Elaeis guineensis Jacq.) is a bulk feeder of nutrients. In this study, we aimed at devising strategies for efficient nutrient management in the oil palm plantations of the Krishna River basin located in Andhra Pradesh, India by assessing soil fertility status, establishing optimal leaf nutrient concentrations and identifying yield restrictive nutrients. In total, 67 oil palm plantations were surveyed from this area in 2020, soil samples were collected and analysed for different soil properties, including pH, EC, SOC, available P, K, S, exchangeable Ca and Mg, and hot water-soluble boron (HWB) in surface (from 0-20 cm depth), subsurface (from 20-40 cm depth) and deep (from 40-60 cm depth) soil layers. As per DRIS (Diagnosis and Recommendation Integrated System) indices estimated in this study, the order of requirement of nutrients is Nitrogen (N) > B > K > P > Mg for this area. Optimum leaf nutrient concentrations ranged between 2.07-4.29%, 0.13-0.27%, 0.52-0.94%, 0.44-0.76% and 44.97-102.70 mg/kg for N, P, K, Mg and B, respectively. In surveyed plantations, about 15, 6, 16, 9 and 12 percent of leaf samples had less than optimum concentration of N, P, K, Mg and B respectively. Nitrogen and Boron are the major yield limiting factors in this region. Leaf nutrient concentrations need to be maintained at the optimum ranges as estimated above for higher productivity in the Krishna basin area.