Abstract

Studies on Soil Test Crop Response based Integrated Plant Nutrition System (STCR - IPNS) were conducted during 2011-12 adopting the Inductive cum Targeted yield model, on a Vertic Ustropept soil of Tamil Nadu, South India in order to develop fertilizer prescriptions for the desired yield targets of transgenic cotton through drip fertigation. The basis for making the fertilizer prescriptions viz. nutrient requirement (NR), contribution of nutrients from soil (Cs), fertilizer (Cf) and farmyard manure (Cfym) were computed using the field experimental data. Making use of these basic parameters, the fertilizer prescription equations were developed under NPK alone and IPNS, and nomograms (ready reckoner of fertilizer doses) were formulated for the desired yield targets of cotton for a range of soil test values. When applied along with the NPK fertilizers as per soil test and desired yield target, the quantity of nutrients that could be contributed by the application of farmyard manure (FYM) @ 12.5 t ha-1 (with 32% moisture, 0.64, 0.31 and 0.61 per cent of N, P and K respectively) for cotton was assessed as 40, 20 and 34 kg fertilizer N, P2O5 and K2O respectively, The per cent reduction in fertilizer N, P2 O5and K2O requirement under IPNSincreased with increasing soil available NPK status.

Keywords: Inceptisol, Transgenic cotton, Fertilizer prescription equations and STCR-IPNS