Different Organic and Inorganic Sources of Plant Nutrients Influence Soil Health, Leading to Improve the Productivity and Profitability of a Fourteen‐Year Long‐Term Rice–Potato–Groundnut Cropping Pattern

This study aims to evaluate the impact of long‐term integrated nutrient management (INM) treatments on soil properties, crop productivity and the soil quality index (SQI) in scented rice–potato–groundnut cropping system. A comprehensive evaluation of soil quality indicators was carried out using four different SQI calculation methods: linear additive (SQI LA ), nonlinear additive (SQI NLA ), linear weighting (SQI LW ) and nonlinear weighting (SQI NLW ). Among all the treatments, the INM approach ( T 1 ), which combines 50% recommended NPK from inorganic fertilizer with 50% N from FYM, resulted in the maximum yield for all three crops. Within the organic nutrient management treatments ( T 2 – T 5 ), treatment T 5 , which involved 33% of the recommended nitrogen from various organic sources combined with beneficial microorganisms, showed significantly higher yield. Of the 17 soil quality attributes in the present study, soil organic C (SOC), available N, available S and total soil bacteria count were identified as the most sensitive indicators influencing soil quality. The plots treated solely with organic inputs with biofertilizers yielded the highest SQI values (SQI LA —4.01; SQI LW —0.71; SQI NLA —3.04; SQI NLW —0.51), closely followed by the INM‐treated plots (SQI LA —3.66; SQI LW —0.66; SQI NLA —2.82; SQI NLW —0.47), and both the treatments significantly outperformed other treatments. All four SQIs showed a high correlation with the system of rice equivalent yield (SREY) calculated from all three crops; however, there are significant differences. The weighted linear (SQI LW ) method proved to be the most sensitive and reliable method for modelling soil quality and predicting crop productivity. The exclusion of biofertilizers from different organic nutrient management options led to 13.36% decline in the SQI value, highlighting the critical role of biofertilizers in maintaining soil health in the scented rice–potato–groundnut system.