2026/06/07 by Dong Wang, Xinyuan Wei, Yu Liu +5 · 2 voices
Agricultural and Biological Sciences · Environmental Science · #Composting and Vermicomposting Techniques #Soil Carbon and Nitrogen Dynamics #Phosphorus and nutrient management
paper · pdf · doi:10.1007/s44246-026-00271-7
openalex publication_date 2026/06/07 · openalex created_date 2026/06/08 · openalex updated_date 2026/07/29
Uncontrolled emissions of nitrogenous gases (NH3 and N2O) during livestock manure composting pose a dual challenge by reducing fertilizer quality and exacerbating atmospheric pollution. In this study, iron-modified biochar (FeBC) was investigated as a dual-functional amendment to simultaneously mitigate nitrogen loss and gaseous emissions during pig manure composting. Compared with pristine biochar (BC), FeBC exhibited a 4.6-fold higher specific surface area and enriched surface functional groups. FeBC significantly reduced cumulative NH3 and N2O emissions by 46.68% and 41.69% relative to the control (21.99% and 11.88% relative to BC), respectively. Metagenomic analysis revealed that FeBC upregulated hao and nxrA genes, accelerating NH4+-N oxidation and thereby suppressing NH3 volatilization. Crucially, FeBC shifted denitrification toward complete N2O reduction by decreasing the abundance of nirK and norB while enhancing nosZ. Furthermore, FeBC reshaped the microbial community structure by selectively enriching nitrogen-retaining functional taxa, including Pseudomonas and Truepera. Microbial network analysis and structural equation modeling further demonstrated that FeBC strengthened the coupling between physicochemical parameters and microbial processes, creating a self-reinforcing regulatory system that stabilized nitrogen transformation and reduced nitrogenous gas emissions. This study highlighted FeBC as a scalable and mechanism-driven amendment that integrates chemisorption with microbial regulation to achieve sustainable, low-emission composting.