By AIT Public Affairs
Rice paddies across East and Southeast Asia are a significant yet often overlooked source of greenhouse gas (GHG) emissions. In particular methane, a greenhouse gas over 34 times more potent than carbon dioxide in retaining heat in our atmosphere, is the primary gas emitted from rice cultivation which contributes to a warmer climate in recent years. While sectors like livestock and landfills have made strides in mitigation, rice farming, especially in smallholder systems, continues to pose challenges. Dr. Simon Guerrero-Cruz, Assistant Professor in the Department of Water Resources and Environmental Engineering, and AIT’s resident environmental microbiologist, is working to address this challenge.
Dr. Simon took inspiration from Einstein’s formula of relativity and did a philosophical analogy and reimagination of its variables using key aspects of this global challenge: GHG emissions, microorganisms, management of anthropogenic ecosystems such as rice agriculture and water & wastewater resources, oriented to mitigation of climate change. This has resulted in his current and future research identity and is applied in his research projects and is a message that he infuses into his teaching and mentoring of the next generation of environmental managers and practitioners in Asia.
A diverse array of microorganisms contributes to the biogenic production of greenhouse gases (GHGs), including methane (CH₄), nitrous oxide (N₂O), and carbon dioxide (CO₂). GHG emissions arise from both natural ecosystems and poorly managed human-engineered systems, such as rice cultivation, wastewater treatment facilities, landfills, and urban water bodies. Additionally, microorganisms capable of oxidizing methane -methanotrophs- play a crucial role in the mitigation of GHG emissions.
Next to the omission of microorganisms in climate change mitigation conversations, one key challenge in current sustainability efforts is that the role of microbes is often limited by environmental conditions. For example, while practices like alternating wet and dry conditions can improve aeration, they also stress methanotrophs due to changing oxygen levels. Long-term farming has also reduced important nutrients in the soil, which affects how well these microbes work. Methanotrophs need certain elements like copper and cerium to function properly and help reduce methane emissions.
The Solution: Sparking Methanotrophic Activity through Micronutrient Amendments
A new project, “MicroSPARK: Sparking Methanotrophic Microorganisms into Action through Missing Micronutrients”, led by Dr. Simon, directly addresses these gaps. The project focuses on restoring key micronutrients, particularly copper and lanthanides, critical to microbial methane oxidation. Funded by EQT Foundation Sweden under the Methane Action Breakthrough Science Grants, this project runs from December 2024 to December 2026.
Building on insights from the latest MicroGRICE project, recent soil assessments in Surin, Thailand revealed severe deficiencies in these metals, posing barriers to effective methane mitigation. Conventional soil tests often emphasize macronutrients, overlooking the micronutrients vital for microbial activity.
The MicroSPARK project takes an innovative approach by introducing targeted metal amendments—affectionately termed “methanotrophic fairy dust”—to reignite microbial activity and maximize methane oxidation in rice paddies. By restoring these missing micronutrients, the project seeks to:
- Boost methanotrophic populations, enhancing methane removal efficiency.
- Optimize soil microbial interactions, reducing nitrous oxide emissions through microbial out competition of unhealthy nitrogen processes.
- Develop new management strategies to integrate microbial micronutrient monitoring into future climate-smart agricultural practices.
This research offers a transformative step forward in applied environmental microbiology and climate mitigation strategies. “By bridging microbiology, nutrient dynamics, and sustainable management; we include a crucial component of soil health in methane mitigation which in turn will result in actionable solutions for methane and nitrous oxide reduction”, said Dr Simon.
“As the project unfolds, the findings could lead to scalable applications in agricultural systems worldwide, redefining how microbial micronutrients are integrated into climate-smart practices” he added.
The project is currently underway, with a new greenhouse for rice soil mesocosms using native soil from Surin, land cultivated for almost a century, where methane emission and oxidation processes are heavily concentrated through long-term traditional management. This project has the potential to scale up as these soils represent a massive area throughout the continent with significant contribution to the global methane budget that needs urgent actions.
Photo Credit: Mr. Pongsakorn (Din) Chantasit and Dr Simon
