Development and Evaluation of Soil Test Crop Response-based Fertilizer Prescription under INM for Improving Wheat Productivity and Profitability in Mollisols

Abstract

Field experiments were conducted during 2018-19 and 2021-22 to develop and evaluate STCR-based fertilizer prescription for wheat (Triticum aestivum L.), respectively. Initially, a soil fertility gradient was established in three strips through graded application of N, P2O5 and K2O in rice grown as an exhaust crop. Thereafter, wheat (as the test crop) was grown under the STCR framework, comprising selected combinations of varying doses of N, P2O5, and K2O and/or in conjunction with farm yard manure (FYM) and biofertilizers (Bf), along with controls in each soil fertility strip. Test crop response was studied for different treatments, and basic parameters were calculated to formulate STCR-based fertiliser prescription equations for wheat. Results revealed that nutrient requirement for producing one quintal wheat grain was 2.42 kg N, 0.278 kg P and 1.89 kg K. Contribution of N, P and K from soil (17.62, 18.21 and 19.14), FYM (20.11, 13.62 and 32.31), FYM + Bf (25.31, 15.48 and 39.20), fertilizer (48.73, 34.73 and 212.50), integrated application of fertilizers, with FYM (49.12, 37.10 and 218.59) and with FYM + Bf (62.32, 38.88 and 266.68), respectively varied considerably. Integrated application of fertilizers with FYM or/and Bf resulted in higher nutrient contribution compared to their sole application. Results of the verification experiment showed that grain yield under STCR-based treatments was within ±10% of targeted yield, with improved agronomic efficiency and net benefit-cost ratio. Findings indicate the applicability of STCR based fertilizer prescription equations in similar soil types and agro-ecological regions after wide validation to sustain wheat productivity and profitability.