Balanced Nutrient Recommendations for Dry Chilli in an Inceptisol of Tamil Nadu based on a Targeted Yield Model

Abstract

Background: Considering the high cost of fertilizers and adverse effect of its overuse on environment and soil health, proper organic manure-fertilizer recommendations on the basis of soil test values, residual effect and yield targets of chilli becomes vital. Methods: Field experiment was carried out on Periyanaickenpalayam soil series of Inceptisol soil order at farmers holding, Dindigul, Tamil Nadu during 2021-2022 after establishment of marked fertility gradient with respect to soil available N, P and K by gradient experiment with fodder sorghum. The test crop experiment with chilli was laid out in a fractional factorial design comprising of 24 treatments with 4 levels of N (0, 50, 100 and 150 kg ha-1), 4 levels for both phosphorus pentoxide (P2O5) and potassium dioxide (K2O). Farmyard manure (FYM) levels were 0, 6.25 and 12.5 kg ha-1.From the field experiment data, the fundamental parameters- nutrient requirement (NR) and nutrients contributions from soil (Cs), fertiliser (Cf) and farmyard manure (Co)-were determined. Result: The percentage of nutrients estimated from fertiliser (%Cf) that contributed towards the total amount of nutrients taken up by dry chilli was calculated to be 44.09, 39.29 and 76.91 per cent of N, P2O5 and K2O, respectively. K2O greater than N greater than P2O5 was seen as the order of the fertiliser nutrient per cent contributions to total nutrient uptake. Incase of nutrient contribution form soil (% Cs) the order is P2O5 greater than N greater than K2O. FYM contributed (% Co) 29.42, 14.40 and 38.73 per cent of N, P2O5 and K2O. One quintal of dry chilli production was estimated to require (NR) 4.24 kg of nitrogen, 1.91 kg of phosphorus pentoxide (P2O5) and 4.80 kg of potassium oxide (K2O) as nutrients. Fertiliser prescription equations (FPEs) for dry chilli and ready reckoners for the operating range of soil test values for the intended yield target experiment under NPK alone and IPNS were built using basic data.