Integrated nutrient management improves resistance and resilience of soil biological indicators under subtropical rice-wheat system

Soils are increasingly under an assortment of environmental pressure, often related to the amplification of anthropogenic activities and understanding the response of soil ecosystems to disturbance is a major challenge. Under such disturbances, soil microbes will try to demonstrate their inherent resistance and resilience. It appears necessary to study these responses, given that microbial communities are the key player in providing resistance to the soil system. Keeping this hypothesis in view, an experiment was conducted to evaluate the resistance and resilience indices of soil biological indicators under various sets of long-term fertilization regimes ranging from inorganic to integrated treatments. Soil samples were taken from a permanent plot experiment and exposed to heat stress by putting them at 48 °C for 24 h to quantify their resistance and resilience pattern. Results showed that the resistance indices for dehydrogenase activity was improved by 16% under integrated nutrient management (INM) plots over 100% recommended dose of fertilizers. Acid and alkaline phosphatase activity under INM was increased by 16% and 6% respectively, over recommended dose of fertilizers. Fluorescein diacetate hydrolyzing capacity and microbial biomass carbon followed the same trends under the heat stress condition. Enumeration of microorganisms after stress showed that the microbial groups can combat the heat stress as reflected from positive resistance values under residue application. Recovery of soil biological parameters under integrated plots indicated partial resilience even after three months of incubation. INM improves resistance and resilience indices of soil biological parameters implying its significance under the current agricultural scenario.