Biochar helps composting go greener by cutting greenhouse gas emissions
Biochar Editorial Office, Shenyang Agricultural University
image:
Biochar amendments mitigate trace gas emissions in organic waste composting: a meta-analysis
view moreCredit: Jingfan Xu, Zhengqin Xiong
A global study has found that adding biochar to organic waste composting can significantly reduce emissions of potent greenhouse gases, offering a promising pathway for sustainable waste recycling and climate change mitigation.
Researchers from Nanjing Agricultural University and Sichuan University of Arts and Science analyzed data from 123 published studies covering more than 1,000 composting experiments worldwide. Their meta-analysis revealed that biochar reduced methane emissions by an average of 54 percent, nitrous oxide by 50 percent, and ammonia by 36 percent, while showing no significant effect on carbon dioxide release.
“Biochar acts like a sponge that improves aeration, absorbs harmful gases, and stabilizes nutrients,” said lead author Jingfan Xu. “This not only helps the environment but also produces higher-quality compost.”
Biochar is a carbon-rich material created by heating organic matter such as crop residues or wood in limited oxygen. When mixed into compost, it can alter microbial activity, enhance oxygen flow, and adsorb reactive nitrogen compounds that would otherwise be lost as ammonia or nitrous oxide. The new study is the first to quantitatively compare how different composting conditions and biochar characteristics influence these gas emissions.
The researchers found that the amount of biochar added is critical. Using 10 to 20 percent biochar by dry weight achieved the strongest reductions in methane, nitrous oxide, and ammonia. However, too little or too much biochar reduced the benefits. The compost’s physical and chemical properties also played a role: neutral to slightly alkaline pH (7.5–8.5), moderate moisture (55–65 percent), and low electrical conductivity favored optimal performance.
“By fine-tuning composting conditions, we can make organic waste recycling much more climate-friendly,” said senior author Professor Zhengqin Xiong. “Our analysis provides practical guidelines for farmers and waste managers to maximize the environmental benefits of biochar.”
Beyond emission reductions, biochar-enriched compost conserved nitrogen, improved pH balance, and helped stabilize carbon in the final product. These findings suggest that integrating biochar into composting systems could support both waste management and agricultural sustainability.
===
Journal Reference: Xu J, Xiong Z. 2025. Biochar amendments mitigate trace gas emissions in organic waste composting: a meta-analysis. Nitrogen Cycling 1: e005 https://www.maxapress.com/article/doi/10.48130/nc-0025-0003
===
About Nitrogen Cycling:
Nitrogen Cycling is a multidisciplinary platform for communicating advances in fundamental and applied research on the nitrogen cycle. It is dedicated to serving as an innovative, efficient, and professional platform for researchers in the field of nitrogen cycling worldwide to deliver findings from this rapidly expanding field of science.
Follow us on Facebook, X, and Bluesky.
Method of Research
Literature review
Subject of Research
Not applicable
Article Title
Biochar amendments mitigate trace gas emissions in organic waste composting: a meta-analysis
The dose-dependent effects of dissolved biochar on C. elegans: Insights into the physiological and transcriptomic responses
image:
The dose-dependent effects of dissolved biochar on C. elegans: insights into the physiological and transcriptomic responses
view moreCredit: Xinrui Wang, Jie Li, Lan Luo, Gang Li, Yan Xu, Weibin Ruan & Guilong Zhang
Researchers have uncovered how dissolved biochar—tiny carbon particles derived from burning plant material—affects soil nematodes, shedding light on both benefits and risks to these important ecosystem players. The study focused on the common laboratory worm, Caenorhabditis elegans, revealing that the impact of dissolved biochar strongly depends on the amount present in the environment.
The team found that when nematodes were exposed to low concentrations of dissolved biochar, their growth and physical activity increased. These smaller doses likely functioned as extra nutrients or provided mild stimulation that encouraged development. However, higher levels of biochar led to a slowdown in growth and triggered signs of metabolic stress, as demonstrated by changes in both the worms' physiology and gene activity.
To understand how these effects occur, scientists tracked the worms' movement, growth, and reproductive patterns, and carried out RNA sequencing to analyze thousands of genes. They observed a "hormetic effect": lower doses helped nematodes thrive, while higher doses disrupted normal metabolic and cellular functions, including pathways involved in stress resistance and even cell death. Importantly, key genes related to growth, stress response, and movement were sensitive to biochar concentration, emphasizing the complexity of the molecular response.
The findings serve as a timely warning to agricultural decision-makers. While biochar is widely promoted for its profits in soil health and carbon sequestration, its dissolved fraction can travel through soils and interact directly with living organisms—sometimes in ways that may harm non-target species. This work highlights the need for careful dosing and oversight when deploying biochar in real-world agricultural systems to ensure safe, sustainable practices.
Researchers recommend further exploration of biochar's long-term impacts on soil nematodes and other wildlife to better understand how best to balance soil restoration with ecological safety. The study illustrates the growing importance of molecular biology tools in environmental risk assessment and sustainable agriculture innovation.
===
Journal Reference: Wang, X., Li, J., Luo, L. et al. The dose-dependent effects of dissolved biochar on C. elegans: insights into the physiological and transcriptomic responses. Biochar 7, 100 (2025). https://doi.org/10.1007/s42773-025-00493-9
===
About Biochar
Biochar is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field.
Follow us on Facebook, X, and Bluesky.
Journal
Biochar
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
The dose-dependent effects of dissolved biochar on C. elegans: insights into the physiological and transcriptomic responses
No comments:
Post a Comment