Soil Physico-chemical Properties as Influenced by Combined use of NPK and Zinc at Varying Levels under Blackgram (Vigna mungo L.) Cultivation in an Inceptisol of Prayagraj, Uttar Pradesh, India

In the modern era, Indian farmers are constantly confronted with the enormous challenge of increasing blackgram production due to low inherent nutrient status, indiscriminate use of chemical fertilizers and rapid depletion of soil fertility. Therefore, the recommended dose of fertilizer application is essential for increasing the nutrient reputation of the soil, with the intention of enhancing the blackgram production in our country. In view of limited information, a field experiment was undertaken at the Research Farm, Department of Soil Science and Agricultural Chemistry, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (U.P), during late kharif season of 2021, to investigate the “Effect of Different Levels of NPK and Zinc on Physico-Chemical properties of Soil, Growth and Yield of Blackgram (Vigna mungo L.) var. RBU-38”. The experiment was laid out in randomized block design (RBD) with 9 treatments randomly allocated into three replications. The treatment consisted of three levels of NPK (0:0:0, 10:20:10 and 20:40:20 kg ha-1) and three levels of zinc (0, 2.5 and 5 kg ha-1). Statistical interpretation of experimental results indicated that application of blended NPK @ 20:40:20 kg ha-1 in conjunction with Zn @ 5 kg ha-1 [T9] performed better in maintaining soil properties by way of registering optimum values of bulk density (1.298 Mg m-3), particle density (2.454 Mg m-3), pore space (47.11%), water holding capacity (40.17%) with neutral in soil pH (7.375), non-saline nature of EC (0.281 dS m-1) and low in organic carbon (0.437%). In case of soil nutrient status, the highest availability of nitrogen (287.08 kg ha-1), potassium (201.53 kg ha-1) and zinc (0.685 ppm) at post-harvest soil of blackgram were also recorded in T9 [N20P40K20 + Zn @ 5 kg ha-1] as compared to other treatments, while maximum phosphorus (25.10 kg ha-1) availability was noted under T7 [N20P40K20 + Zn @ 0 kg ha-1] due to the antagonistic relationship between phosphorus and zinc.