Targeted Nutrient Management with FYM in Brassica juncea on Vertisols: Evaluation of Nutrient Use Efficiency and Yield Response

Abstract

This study assesses the impact of STCR-based fertilizer prescriptions combined with farmyard manure (FYM) on grain and straw yield, nutrient uptake, and nutrient use efficiency in mustard grown on Vertisols of Chhattisgarh. A factorial randomized block design with three replications encompassed 16 treatments to evaluate targeted N, P, and K regimes, with and without FYM, across yield-targets of 14, 18, and 22 q ha−1. Grain and straw yields showed positive responses to STCR-based doses, with the peak grain yield reaching 21.79 q ha−1 under the 22 q ha−1 yield-target treatment (T8). Across yield targets, FYM generally enhanced nutrient use efficiency, although its influence on total uptake of N, P, and K varied with the mineral fertilizer regime. Nitrogen uptake was highest under the STCR-based dose, while phosphorus and potassium uptakes followed similar trajectories, with T8 frequently achieving the greatest total uptake. Interaction effects between FYM and fertilizer regimens were largely non-significant, indicating additive effects under the tested conditions. Omitting nitrogen markedly reduced yield and nutrient uptake, underscoring N essential role in mustard productivity. The results substantiate the effectiveness of STCR-guided nutrient prescriptions and support integrating inorganic inputs with organic amendments to stabilize yields, optimize nutrient acquisition, and enhance resource-use efficiency in Vertisol-based mustard systems. Implications for extension services and policy emphasize soil-test-guided management to achieve targeted yields while potentially reducing input costs.