Rice in acid sulphate soils: Role of microbial interactions in crop and soil health management

Acid sulphate soils are one of the most problematic soils in the world. Unless appropriately ameliorated, these soils are difficult to manage due to several constraints like high acidity and salinity, metal toxicity, nutrient unavailability, redox fluctuations, overlying sulfidic materials (pyrite), and other factors. The microbial-mediated processes related to nutrient cycling in these soils are complex and unique. Chemical methods to manage these soils have led to large changes in microbial dynamics and their activities, environmental disturbances, and even productivity declines. The growing demand for sustainable rice production in these soils necessitates the development of biologically relevant practices with positive environmental gains. The present review addresses the mechanisms involved in microbially mediated nutrient cycling and functional diversity among the microbial communities in acid sulphate soils. The challenges and opportunities for the biological management of these soils for paddy cultivation are also discussed. Future research on microbial metabolic processes, long-term effects of biological management, and sustainable cultivation methods can make effective use of these soil resources.