Prediction of Post-harvest Soil Test Values and Fertilizer Calibrations for a Maize Based Cropping Sequence under Integrated Plant Nutrition System

Abstract

Field experiments were conducted based on Inductive cum targeted yield concept on Typic Haplustert soils (Pilamedu series - black calcareous) to predict the post-harvest soil test values for prescribing soil test crop response based fertilizer doses under Integrated Plant Nutrition System (STCR-IPNS) for maize based cropping sequence. The experiment comprised of 24 treatments with four levels each of N (0,100,200 and 300 kg ha-1), P2O5 (0,40,80 and 120 kg ha-1) and K2O (0,40,80 and120 kg ha-1) and three levels of FYM (0, 6.25 and 12.5 t ha-1) for the test crop maize (TNAU Maize hybrid CO 6) laid out in fractional factorial design. Making use of the experimental data on initial and post-harvest soil test values, fertilizer doses and the grain yield obtained or uptake of N,P and K by maize, Post-Harvest Soil Test Values (PHSTVs) prediction equations with high R2 values (>0.90) were developed, which could be used with confidence for the prediction of post-harvest KMnO4-N,Olsen-P and NH4OAc-K. Using the predicted PHSTVs after kharif maize, soil test based fertilizer prescription for desired yield target of succeeding crop viz., cotton could be prescribed.