Asian Journal of Advances in Research

Waterlogging is increasing globally because of higher rainfall variability and inadequate soil drainage. In waterlogged soils, oxygen diffusion becomes limited, resulting in anoxia and hypoxia, which significantly affect microbial processes, soil biogeochemical reactions, and crop productivity. This review highlights the adaptability of soil microorganisms to waterlogging and explains how they contribute to recovery from stress and support plant tolerance. Under oxygen-limited conditions, soil microorganisms use metabolic adaptations, including denitrification, metal reduction and fermentation, to sustain energy production. In addition to these metabolic defence strategies, microorganisms use physical structures, such as biofilms and exopolysaccharides, and reorganise microbial populations within the environment to cope with flooding-related stress. After water removal, microorganisms experience oxidative stress during re-oxygenation; however, antioxidant defence mechanisms and cell-repair activities can help restore microbial functioning. Soil microbes also support plants under waterlogged conditions by regulating rhizosphere processes, improving nutrient availability, adjusting ethylene levels through ACC deaminase activity and promoting root recovery. These microbial activities are important for nutrient cycling, decomposition, soil aggregation and agroecosystem resilience. The synthesis also indicates that microbial responses during flooding and drainage should be considered together because both phases influence soil biological recovery and plant performance. Improved understanding of microbial adaptation and resilience under changing oxygen conditions may support sustainable management practices that enhance soil fertility and agricultural production in flood-prone systems.