Zhou, et al (2024) Biochar-based urea increases soil methane uptake in a subtropical forest. Geoderma. https://doi.org/10.1016/j.geoderma.2024.116994

Recent research highlights the significant potential of biochar-based urea to enhance soil methane (CH4) uptake, offering an effective strategy to mitigate greenhouse gas emissions in subtropical forests. Methane is a potent greenhouse gas, and forest soils play a crucial role in its oxidation, helping to reduce its concentration in the atmosphere.

A three-year field study in a subtropical Moso bamboo forest compared the effects of traditional urea and biochar-based urea on soil methane uptake. Traditional urea, widely used for its nitrogen content, was found to reduce soil methane uptake due to its impact on soil microbial communities. Specifically, urea application increased the abundance of methanogens—microbes that produce methane—by creating anaerobic conditions that favor methane production.

In contrast, biochar-based urea significantly increased methane uptake by enhancing soil aeration and providing a slow-release supply of labile carbon. These conditions favor the growth of methanotrophic bacteria, which oxidize methane, thus increasing the abundance of pmoA genes associated with methane oxidation.

The study suggests that switching from traditional urea to biochar-based urea in subtropical forests like those in China could substantially increase the soil’s methane uptake, potentially reducing the overall methane concentration in the atmosphere. This approach not only supports forest soil health but also offers a viable strategy for reducing the greenhouse effect, highlighting the importance of innovative agricultural practices in combating climate change.