Closing nutrient loops is vital for sustainable agriculture and remediation. Modern farming relies on linear nutrient flows, where much of the input is lost via leaching, runoff, or emissions, causing soil degradation, water pollution, and climate impacts. Chars (including biochar) and organic amendments offer tools to restore soils, improve nutrient efficiency, and aid remediation. Their integration supports circular systems that enhance fertility, crop yields, and environmental quality.

Individually, chars and organic amendments boost soil organic matter, water retention, pollutant immobilization or degradation, and nutrient supply. When used together, they create synergies beyond single effects: improved soil–water–plant interactions, stronger nutrient cycling, stabilization of soil structure, and reduced nutrient losses. They also help cut harmful emissions, including greenhouse gases and ammonia, while avoiding toxic accumulation.

Although, their effectiveness depends on feedstock, production and composting methods, particle size, rates, and biogeochemical context. Outcomes also vary with climate, soil texture, hydrology, and management. Therefore, understanding these interactions is essential for optimizing use and ensuring long term impact.

This session aims to address:

• Field and lab experiments on productivity, nutrient efficiency, and soil health.
• Remediation of polluted soils and aquatic systems.
• Modeling nutrient cycling, pollutant dynamics, and amendment behavior.
• Life cycle assessment and sustainability studies.
• Effects of feedstock, processing, and composting methods (composting, co‑composting, aging).
• Investigations on emissions, volatilization, and leaching.
• Innovative practices and case studies for nutrient cycling and remediation.

We welcome contributions from experimental, modeling, and interdisciplinary research linking agronomy, soil science, hydrology, and sustainability. By engaging researchers, including early career scientists, this session seeks to identify best practices and innovative strategies for advancing nutrient management and remediation.