Effect of STCR based NPK application on yield, quality of soybean and available nutrient status in a Vertisol of Madhya Pradesh

Abstract:

A field experiment was conducted at the Research Field of the Department of Soil Science and Agricultural Chemistry, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Madhya Pradesh during kharif season of 2015-16 to evaluate the effect of NPK fertilization on productivity, seed quality of soybean and available nutrient status in post-harvest soil under STCR approach. The study was consisting of five treatments of NPK doses comprised of control, GRD and three yield targets (25, 30 and 35 q ha⁻¹), which were replicated four times in a Randomized Block Design. Results indicated that the maximum seed (15.96 q ha^-1) and stover (26.72 q ha^-1) yields of soybean were recorded under higher yield target of 35 q ha^-1, which marked a 94.4% increase over the control and greatly exceeded the general recommended dose (GRD). Quality parameters of soybean seed such as oil (19.65%), protein (41.63%) and starch (59.43%) contents consistently increased with upward NPK doses, although variations between high-target yield treatments were statistically equal. Post-harvest soil analysis showed that STCR-based NPK fertilization greatly increased available nitrogen, phosphorus and potassium compared to the control and GRD, effectively preventing nutrient mining. The study concludes that the STCR approach enhances soybean productivity, improved seed quality and maintaining soil fertility, especially at higher yield targets. This STCR approach offers a sustainable and scientifically sound substitute for blanket fertilizer recommendations for improving farm profitability and soil health in the Vertisol of Central India.