Recalibration of Targeted Yield Equations through Integrated Plant Nutrition System for Greengram (Vigna radiata L.) on Alfisol

In India, greengram (Vigna radiata L.) is a popular pulse crop. With the concern for achieving desired yield with ensured soil health, the Soil Test Crop Response (STCR) approach develops the fertilizer prescription equations (FPEs) for the desired yield in greengram by conducting a field experiment on red non-calcareous, sandy loam soil belonging to Palaviduthi soil series (Typic Rhodustalf) during rabi 2021-22. The experiment includes 11 treatments viz., Absolute control (T1), FYM @ 6.25 t ha-1 (T2), 12.5 t ha-1 (T3), STCR-based NPK fertilizer recommendations (STCR-NPK) for the targeted yield of 1.0 (T4),1.2 (T5),1.4 t ha-1 (T6), STCR-NPK+FYM @12.5 t ha-1 for the targeted yield of 1.0 (T7),1.2 (T8),1.4 t ha-1 (T9), Blanket (100% RDF) (T10) and Blanket (100% RDF) +FYM @12.5 t ha-1 (T11), in Randomized Block Design (RBD) with three replications. The results revealed that a high targeted yield of 1.4 t ha-1 T9 (STCR-NPK+FYM @12.5 t ha-1) was more supercilious than others. Initial soil test values, grain yield, total nutrient uptake, applied fertilizer doses and farmyard manure were used for obtaining four important basic parameters such as nutrients required to produce one quintal grain (NR), contribution of nutrients from soil (%Cs), contribution of nutrients from fertilizer (%Cf), as well as contribution of nutrients from FYM (% Cfym). The nutrient requirement of greengram to produce one quintal of grain yield in terms of N, P2O5, and K2O were 4.77, 3.58 and 5.42 kg q-1, respectively. The per cent contribution of nutrients from soil, fertilizer and FYM were 14.00, 48.90 and 34.11 for nitrogen; 36.51,29.59 and 10.24 for phosphorus; and 7.00, 62.65 and 32.12 for potassium, respectively. By using these basic parameters, the fertilizer prescription equations were formulated for greengram in Palaviduthi soil series.