In a recent study published in the Journal of Environmental Management, Yunyun Zheng and colleagues from the UWA School of Agriculture and Environment investigated the impact of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, combined with digestate, on nitrous oxide (N2O) emissions from soil. The research explored how this soil amendmentA soil amendment is any material added to the soil to enhance its physical or chemical properties, improving its suitability for plant growth. Biochar is considered a soil amendment as it can improve soil structure, water retention, nutrient availability, and microbial activity.   More strategy affects N2O emissions, a potent greenhouse gas, and the underlying microbial processes in soils with varying pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More levels.  

Anaerobic digestion of organic materials produces digestate, a substance rich in nitrogen and organic matter. Combining biochar, a carbon-rich material produced from biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More, with digestate can create a C- and N-enriched biochar fertilizer. This combination aims to reduce problems associated with digestate use, such as nitrogen loss and odor, while harnessing biochar’s ability to suppress N2O emissions.  

Zheng et al. conducted a study using ryegrass grown in soil treated with different nitrogen fertilizers: urea, urea plus biochar, solid digestate, and digestate-incorporated biochar. The experiment was performed with and without liming to alter soil pH. The researchers then measured N2O emissions and analyzed the soil for microbial community composition and the abundance of genes involved in nitrogen cycling. The study revealed several key findings: Solid digestate and urea plus biochar decreased N2O emission by 48% and 56%, respectively, relative to urea under non-liming. Digestate-incorporated biochar further decreased N2O emission by 75% compared to solid digestate. Liming, a process to increase soil pH, resulted in the lowest N2O emissions across all treatments.  

The researchers also investigated how these treatments affected soil microbes. They found that digestate-incorporated biochar altered the abundance of specific microbial genes involved in N2O production and consumption. This suggests that biochar influences the microbial processes that control N2O emissions. Zheng et al. concluded that digestate-incorporated biochar is a promising strategy to reduce N2O emissions from soil while also providing a source of nitrogen for plants. This approach could contribute to more sustainable agricultural practices and help mitigate greenhouse gas emissions.  

Source: Zheng, Y., Abbott, L. K., Bolan, N., Hu, H., Jenkins, S. N., & Mickan, B. S. (2025). Biochar interacted with organic compounds from digestate in controlling N2O emissions. Journal of Environmental Management, 385, 125591.