Rice Productivity in Saline–Alkaline Soils: Constraints, Microbiome‐Mediated Regulation and Management Strategies

ABSTRACT

Saline–alkaline soils are widespread and represent a particularly restrictive environment for rice, especially in arid and semi‐arid regions. These soils commonly combine elevated salinity with high pH, sodium‐related soil constraints and bicarbonate/carbonate accumulation, resulting in severe physicochemical and nutritional limitations. Under field conditions, saline–alkaline stress can substantially reduce rice productivity, although the magnitude of yield loss varies with stress intensity, duration, developmental stage and genotype. Although substantial progress has been made in understanding rice responses to salinity and alkalinity at physiological and molecular levels, these improvements have not consistently translated into yield gains under field conditions. This mismatch reflects the combined effects of root‐zone degradation, reproductive‐stage sensitivity, nutrient limitations and spatial heterogeneity of stress environments. This review synthesizes current knowledge from four interconnected perspectives: (i) soil physicochemical and nutritional constraints; (ii) rice physiological and developmental responses with emphasis on yield formation; (iii) rhizosphere microbiome‐mediated regulation of plant performance; and (iv) agronomic management strategies under saline–alkaline conditions. Available evidence indicates that microbiome–plant–soil interactions may influence nutrient availability, ion homeostasis and soil structural stability, but the magnitude and persistence of these effects depend strongly on soil conditions, rice genotype, and management practices and remain insufficiently validated under field conditions. A key contribution of this review is the development of an integrative framework that links soil constraints to yield‐limiting processes through plant and microbiome responses, thereby connecting stress alleviation more explicitly with yield formation. Improving productivity in saline–alkaline rice systems will likely require coordinated strategies that integrate genetic tolerance, nutrient management, water regulation, soil amendments and microbiome‐informed approaches according to local field constraints.