Asian Journal of Soil Science and Plant Nutrition

Site-specific nutrient management (SSNM) can improve the synchronisation of nutrient supply with crop requirements in transplanted rice. A field experiment was conducted during Kharif 2023 at the Agricultural Research Station, Mugad, Dharwad, Karnataka, to compare the Recommended Package of Practices (RPP), Soil Test Crop Response (STCR), Rice Crop Manager (RCM), Nutrient Expert (NE) and an absolute control across two rice varieties in a split-plot design with three replications. Growth, yield attributes, grain and straw yield, nutrient uptake, nutrient-use efficiencies, post-harvest soil properties and economic returns were assessed. Among the nutrient-management treatments, RCM (111.05:31.05:39.00 kg N:P₂O₅:K₂O ha⁻¹ + 5 t FYM ha⁻¹) produced the highest grain yield (51.33 q ha⁻¹) and straw yield (71.25 q ha⁻¹), together with strong performance for major growth and yield attributes. RCM also recorded the highest total nitrogen and potassium uptake and the highest economic returns among the evaluated treatments. Post-harvest soil properties showed comparatively modest treatment effects, while SSNM treatments maintained available nutrient status under the conditions of the experiment. Grain yield was strongly and positively associated with plant nitrogen and phosphorus uptake, plant height, nutrient-use-efficiency indices, and panicle and tiller number. The findings indicate that field-specific nutrient recommendations, particularly RCM-based management, can improve productivity and nutrient utilisation in transplanted rice. Multi-season and multi-location validation is required before broader conclusions on long-term soil-fertility effects are drawn.