Impacts of Long-Term Nutrient Management Based on Soil Test and Crop Response on Soil Health and Yield Sustainability in Typic Haplustalf

We studied the effect of soil tests and crop response-based long-term nutrient management on yield sustainability and soil health under rice-rice system in a Typic Haplustalf. The experiment was designed in randomized block design having five treatments, viz, control, the recommended dose of fertilizer (RDF), STCR–NPK for target yield of 6 t ha–1 for kharif rice and 5 t ha–1 for rabi rice (STCR–NPK6), STCR–NPK for 7 t ha–1 for kharif rice and 6 t ha–1 for rabi rice (STCR–NPK7), and STCR–IPNS for 7 t ha–1 for kharif rice and 6 t ha–1 for rabi rice (STCR–IPNS7), and these treatments were replicated thrice. The 10-year mean data suggested that minimum yield was observed from control whereas highest was achieved in STCR–IPNS7 in both kharif as well as rabi seasons. The highest sustainable yield index (SYI) was 0.93 in kharif and 0.77 in rabi rice was observed under STCR–IPNS7, and lowest in control. Soil fertility status revealed that disregard for external application of nutrients resulted in depletion of 108 kg N, 11.6 kg P, and 200 kg K ha-1 and intensity of nutrient depletion was lowest in STCR–IPNS followed by STCR–NPK7, STCR–NPK6, and RDF. The urease, phosphatase, and dehydrogenase activities and microbial biomass C were found to be higher in STCR–IPNS when compared with other nutrient management practices while minimum values were recorded in the control.