Impact of Long Term Fertilization on Soil Properties and Soybean Productivity in a Vertisol

The present investigation was conducted during 2018-19 under All India Coordinated Research Project on “Long Term Fertilizer Experiment” at the Research Farm Department of Soil Science and Agricultural Chemistry, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (M.P.), which was commenced since 1972, to assess the effect of continuous application of different fertilizer with or without organic manure on soil fertility and soybean productivity. There was ten treatments i.e. T1 (50% NPK), T2 (100% NPK), T3 (150% NPK), T4 (100% NPK + Hand weeding), T5 (100% NPK + Zn), T6 (100% NP), T7 (100% N), T8 (100% NPK + 5 t FYM ha-1), T9 (100% NPK-S) and T10 (Control), which replicated four times in a randomized block design. The findings of the present investigation revealed that the application of recommended dose of N, P and K (20:80:20 kg ha-1) with organic manure (@ 5 FYM ha-1) enhanced soybean crop yields over control plot. Further, the integrated use of FYM with 100% NPK substantially improved the organic carbon content by 2.9 g kg-1 as well as available N and P in soil over its initial values, thereby indicating significant contribution towards sustaining the soil health. Thus, the balance use of fertilizers continuously either alone or in combination with organic manure is necessary for sustaining soil fertility and soybean productivity.