Soil Test Based Fertilizer Prescriptions through Inductive cum Targeted Yield Model for Sesamum on Alfisol

Studies on Soil Test Crop Response Based Integrated Plant Nutrition System (STCR-IPNS) were conducted for three years adopting the Inductive cum Targeted Yield Model, on alfisols of Unified Andhra Pradesh, Southern India during summer 2016-2018 in order to develop fertilizer prescriptions through IPNS for the desired yield targets of Sesamum under field conditions. The bases for making the fertilizer prescriptions viz. nutrient requirement (NR), contribution of nutrients from soil (Cs), fertilizer (Cf) and vermicompost (CVC) were computed using the field experimental data. Making use of these basic parameters, the fertilizer prescription equations were developed under NPK alone and under IPNS for the desired yield targets of Sesamum for a range of soil test values. The quantity of fertilizers contributed by the application of vermicompost was assessed. Nutrient requirement to produce 100 kg of sesame seed was worked out to be 10.20 kg N, 3.90 kg P₂O₅ and 5.22 kg K₂O. In the present investigation, the requirement of N was higher which is followed by K₂O and P₂O₅. The requirement of N was 2.62 times higher than P and 1.95 times higher than K. The percent contribution of N, P and K was 12.25, 15.75 and 6.00 from soils, 41.68, 22.85 and 59.97 from fertilizer and 9.87, 6.74 and 18.65 from organic manures, respectively. Thus the Inductive cum Targeted Yield Model used to develop fertilizer prescription equations provides a strong basis for soil fertility maintenance consistent with high productivity and efficient nutrient management in farming for sustainable and enduring agriculture.