Integrated STCR fertilization in mustard: Assessing yield response, gross return, and nutrient-use efficiency

Abstract

This study assesses mustard responses to STCR-based fertilizer management, combining soil-test-driven prescriptions with farmyard manure (FYM) across a spectrum of treatments. The experimental framework aimed to quantify yield responses and response ratios, as well as nutrient-use efficiencies and the economic implications of different fertilizer regimens. Among the treatments, the yield-target strategy at 22 q ha−1 (YT 22 q ha−1; T8) delivered the highest grain yield, exceeding the conventional yield target of 6 t ha−1 (T5) and other regimens. STCR-based doses generally outperformed conventional inorganic schedules, with FYM-inclusive programs producing greater grain outputs than sole chemical fertilization. The observed yield gains translated into higher gross and net returns for the yield-target STCR approach, though the benefit-cost ratio (B:C) varied with input costs, reflecting a trade-off between maximizing yield or net benefit and achieving economic efficiency per unit input. The response ratio, defined as grain yield per unit nutrient applied, differed among treatments, with T7 and T2 leading in efficiency despite elevated absolute yields for T8, indicating that yield targets interact with baseline fertilization to shape nutrient-use efficiency. Nitrogen emerged as a primary driver of both yield and profitability, consistent with STCR principles that align nutrient provisioning with crop demand. Across N, P, and K, nutrient-use efficiencies were higher under STCR prescriptions than under blanket applications, and FYM generally enhanced nutrient recovery, though per-unit efficiency depended on dose and interactions with mineral inputs. Overall, these results support STCR-based nutrient management, particularly when integrated with FYM, as a means to optimize yield, nutrient uptake, and economic performance in mustard systems.