Reconstruction of fertiliser prescription equations for hybrid bhendi under drip fertigation through STCR-IPNS approach on Inceptisol

A field experiment was conducted on Palaviduthi soil series (Typic haplustalf, Red non- calcareous, sandy loam soil) by adopting the Soil Test Crop Response (STCR) under Integrated Plant Nutrition System (IPNS) approach during rabi season of 2021-22 with the main objective of reconstruction of fertiliser prescription equations for hybrid bhendi (COBhH-4) under drip fertigation using the existing fertiliser prescription equations for bhendi variety grown under conventional method fertiliser application and surface irrigation on a Periyanaickenpalayam soil series (Vertic Ustropept, Mixed black calcareous, clay loam soil). The field experiment consisted of eleven treatments viz., absolute control, FYM @6.25 and @ 12.5 alone, STCR-NPK alone and STCR-IPNS for targeted yield of 18, 20 and 24 t ha-1 , blanket recommendation with 100% RDF (200:100:100 kg NPK ha-1 ) and 100% RDF + 12.5 t ha-1 FYM which were replicated thrice in randomized block design (RBD). The basic parameters viz., nutrient requirement (NR), contribution of nutrients from soil (Cs), fertiliser (Cf) and farmyard manure (Cfym) were calculated from field experiment data. It has been found that the nutrient requirement (NR) for producing one quintal of bhendi fruit 0.52 kg of N, 0.18 kg of P2O5 and 0.59 kg of K2O were required. The per cent contribution of nutrients from soil (Cs) as 22.63, 28.69 and 10.03 of N, P2O5 and K2O respectively, per cent contribution from fertilisers (Cf) as 39.34, 22.65 and 55.18 of N, P2O5 and K2O respectively and per cent contribution from FYM (Cfym) as 35.79 for N, 9.40 for P2O5 and 27.58 for K2O. Using these basic parameters, the fertiliser prescription equations were reconstructed by adopting Soil Test Crop Response under Integrated Plant Nutrition System (STCR-IPNS) and nomograms were formulated for the suitable yield target of hybrid bhendi for a range of soil test values under drip fertigation