Establishment and Evaluation of Soil Fertility Gradient on the Basis of Sorghum Fodder Yield, Nutrient Uptake and Post-Harvest Soil Test Values

Field experiment was carried out with fodder sorghum at N.E. Borlaug Crop Research Centre, G.B.U.A.&T., Pantnagar during kharif, 2022 under AICRP on Soil Test Crop Response (STCR) approach aimed to establish and evaluate soil fertility gradient on the basis of sorghum fodder yield, nutrient uptake and post-harvest soil test values. The experimental field was divided into three plots, each receiving graded levels of N, P2O5 and K2O: N0P0K0 (Plot A), N100P100K100 (Plot B) and N200P200K200 (Plot C). Thereafter, fodder sorghum was grown and fodder yield was recorded from each plot. Chemical analysis of plant samples was performed to estimate nitrogen, phosphorus and potassium content and total nutrient uptake was worked out. Post-harvest soil samples were collected across the three plots and analysed for available N, P and K. Findings revealed wide variation in sorghum fodder yield, nutrient uptake and post-harvest soil fertility status for available N, P and K in different plots confirming the establishment of soil fertility gradient for the respective nutrients. The establishment of soil fertility gradient is necessary and serves as a pre-requisite for developing improved nutrient management strategies i.e. STCR-based fertilizer recommendations to sustain crop yield and optimize fertilizer requirements.