Soil Biological and Physicochemical Drivers of Nutrient Cycling in Agroecological Systems for Sustainable Food Production

Global agriculture is currently facing an unprecedented challenge of producing sufficient food for a growing population while minimizing environmental degradation and maintaining ecosystem integrity. Over the past several decades, agricultural intensification has relied heavily on synthetic fertilizers and external inputs to sustain crop productivity. While these inputs have significantly increased yields, their excessive and inefficient use has resulted in multiple environmental problems, including soil degradation, nutrient imbalance, greenhouse gas emissions, water pollution, and biodiversity loss. These challenges highlight the urgent need to rethink nutrient management strategies and transition toward more sustainable agricultural systems that harness natural ecological processes.Agroecology has emerged as a transformative framework that integrates ecological principles into agriculture. A central pillar of agroecological systems is nutrient cycling, which involves the continuous transformation, movement, and reuse of essential elements such as nitrogen (N), phosphorus (P), potassium (K), carbon (C), and other nutrients within agroecosystems. Unlike conventional agriculture that depends on external nutrient inputs, agroecology systems emphasize internal nutrient flows driven by interactions among soil organisms, plants, animals, and organic residues. These processes are regulated through complex biological networks, including soil microbial communities, mycorrhizal fungi, earthworms, and other soil fauna that facilitate nutrient stabilization, mobilization, and mineralization. Understanding nutrient cycling therefore requires consideration of both the plant and soil subsystems, with the soil subsystem playing a critical role in regulating nutrient availability, transformation, retention, and loss.The soil subsystem is a dynamic biogeochemical environment where biological and abiotic processes jointly regulate nutrient cycling. Soil microorganisms—including bacteria, fungi, archaea, and other microbial groups—mediate key processes such as decomposition, mineralization, immobilization, nitrification, denitrification, phosphorus solubilization, and other nutrient transformations. Mycorrhizal fungi facilitate plant nutrient acquisition, particularly phosphorus, through extensive fungal networks and regulate carbon–nutrient exchange between plants and soil. Earthworms and other soil fauna contribute to organic matter decomposition, soil aggregation, bioturbation, and nutrient redistribution. Recent advances in soil microbiology and molecular approaches have revealed the importance of microbial functional diversity, microbial networks, extracellular enzymes, microbial necromass, and plant–microbe interactions in regulating nutrient availability and retention. In parallel, abiotic soil properties—including soil organic matter, pH, texture, mineralogy, moisture, temperature, redox conditions, and aggregate structure—strongly influence microbial activity and the sorption, stabilization, mobilization, and transport of nutrients. The interactions between biological and abiotic processes ultimately determine whether nutrients are retained and recycled within the soil–plant system or lost through leaching, runoff, volatilization, and gaseous emissions. Thus, advancing our understanding of soil biological and physicochemical processes is essential for developing agroecological systems with efficient and sustainable nutrient cycling.Nutrient cycling is therefore increasingly recognized as a key ecosystem service that supports agricultural productivity while enhancing environmental sustainability. Efficient nutrient cycling can improve soil fertility, increase nutrient-use efficiency, and reduce nutrient losses to the atmosphere and water bodies. Practices such as biological nitrogen fixation through legumes, crop diversification, cover cropping, composting, organic amendments, agroforestry integration, and crop–livestock integration can significantly enhance nutrient retention and recycling within farming systems. These strategies not only reduce dependence on synthetic fertilizers but also strengthen the resilience of agricultural systems to climate variability, drought, flooding, and other environmental stresses. However, the effectiveness of these practices depends strongly on the underlying soil biological and physicochemical processes that regulate nutrient availability, transformation, and retention.Particular sub-themes of interest include:· Nutrient cycling as an ecosystem service: pathways, rates, and management levers across scalesSoil biota and nutrient regulation: microbial communities, microbial networks, mycorrhizae, earthworms, mesofauna, and their roles in nutrient transformation and retention· Microbial mechanisms of nutrient cycling: mineralization, immobilization, nitrification, denitrification, phosphorus solubilization, extracellular enzymes, microbial necromass, and plant–microbe interactions· Reducing synthetic fertilizer dependency: strategies to maintain yields and quality with lower external N and P inputs· Biological nitrogen fixation and legume integration: grain legumes, forage legumes, intercrops, and inoculants· Phosphorus stewardship and circularity: mobilization, mycorrhizal roles, recycled P sources, and regional nutrient balancesAbiotic regulation of nutrient cycling: soil organic matter, pH, texture, mineralogy, moisture, temperature, redox conditions, aggregation, and nutrient sorption–desorption processes· Soil food webs and fertility: microbial networks, mycorrhizae, earthworms/mesofauna, and links to nutrient availability· Organic amendments and regenerative fertility: composts, manures, mulches, biochar, and trade-offs (e.g., GHGs, contaminants)· Diversified cropping systems: rotations, cover crops, intercropping, relay cropping, and yield stability under low-input management· Integrated crop–livestock systems: nutrient redistribution, manure management, grazing in rotations, and disease/weed dynamics· Agroforestry and perennial systems: deep nutrient capture, litter inputs, microclimate effects, and nutrient retention· Nutrient losses and water quality: leaching/runoff, buffer strips, riparian zones, wetlands, and landscape nutrient filtering· Measurement and monitoring: soil health indicators, nutrient budgets, isotopes, eDNA, remote sensing, and farmer-friendly metrics· Trade-offs and co-benefits: productivity, biodiversity, GHG emissions (N₂O), labor, and economic viability· Scaling and transitions: adoption barriers, incentives, policy tools, supply-chain drivers, and equity outcomes Topic editors: Md Manik Ali, Muhammad Madnee, SHAFIQUL Bari Source: https://www.frontiersin.org/research-topics/79025/soil-biological-and-physicochemical-drivers-of-nutrient-cycling-in-agroecological-systems-for-sustainable-food-production