Soil Structure and Crop Productivity: Processes, Indicators, and Sustainable Management Approaches

Soil structure is a key determinant of soil physical quality, regulating water infiltration, hydraulic conductivity, gas exchange, root proliferation, nutrient cycling, and crop productivity. This review examines current knowledge on soil aggregation mechanisms, soil crusting and clodding processes, structural degradation, and the role of soil conditioners in improving soil physical quality. Crusting, often resulting from surface compaction and particle disaggregation, hampers seedling emergence and water absorption. Clod formation increases soil mechanical resistance, impedes seedling establishment, restricts root elongation, and reduces tillage efficiency. The review highlights how appropriate soil management practices and amendments both organic and inorganic can improve aggregation, porosity, and structural resilience, thereby alleviating these challenges. Soil structure is closely tied to the stability of aggregates, formed through particle rearrangement, flocculation, and cementation. Key mediators in these processes include clay, soil organic carbon (SOC), ionic bridges, carbonates, and biological exudates. While expanding clays may disrupt aggregates, fine particles and SOC enhance aggregation through flocculation and binding. Microbial, plant, and faunal exudates contribute to SOC, which not only promotes aggregation but also depends on its stability and resistance to microbial decomposition. This article integrates findings from recent studies and field observations to propose context‑specific strategies for optimizing soil structure. The insights are particularly relevant for farmers, agronomists, and researchers aiming to mitigate soil degradation and enhance long‑term productivity. Enhancing soil structure is essential not only for crop performance but also for maintaining environmental sustainability under varying edaphic and climatic conditions.