Fertilizer-Prescription Equations for Targeted Yield in Radish under Integrated Nutrient Management System

Abstract

Soil test crop response correlation studies under integrated plant nutrient system were carried out in Inceptisol of West Bengal during 2008 - 2010, with radish as a test crop following Ramamoorthy's 'inductive-cum-targeted yield model'. Four fertilizer (NPK) and three farmyard manure (FYM) levels were randomized in three well-established fertility gradients, each comprising 21 plots. Soil and plant analysis data were interpreted to formulate fertilizer adjustment equations, with or without FYM, at varying yield targets. It was computed that 1.40, 0.17 and 2.8 kg N, P and K, respectively, were required for producing 100 kg of radish. Contribution of fertilizer-source to the total NPK uptake in radish was far higher than that obtained from FYM and soil available sources. A ready-reckoner developed from soil-test based fertilizer adjustment equations showed that FYM application at 10 t ha^-1, along with NPK fertilizer, resulted in a net saving of 15, 1.8 and 5.0kg ha^-1 of N, P and K, respectively, for cultivating radish.