Prediction of post-harvest soil test values and fertilizer calibrations for a rice based cropping sequence under integrated plant nutrition system

摘要

Soil test crop response studies were conducted in Typic Ustropept soils to predict the post-harvest soil test values thereby prescribing soil test and target based fertilizer doses for a rice-rice-residual blackgram sequence under Integrated Plant Nutrition System (IPNS). For both kharif and rabi seasons, Post-Harvest Soil Test Values (PHSTV) prediction equations were developed from the initial soil test values, fertilizer doses and the grain yield obtained or uptake of nutrients. High R~2 values (>0.90) were recorded for these regression equations which could be used with confidence for the prediction of post-harvest KMnO_4-N, Olsen-P and NH_4OAc-K. Using the predicted PHSTVs of kharif rice, soil test based fertilizer recommendation for any desired yield targets of succeeding rabi rice could be prescribed. The prediction of PHSTVs of rabi rice suggested the fertility status of the soil for raising residual pulse crop.