Biological-based or biological models for methane capture

Summary

The project aim was to research biological methods relating to methane sources or sinks in livestock grazing systems. Methods identified could be included in Australia’s Carbon Marketplace to incentivise producers and increase adoption to technologies and practices to reduce methane emissions or store carbon. Future R&D includes research of how various trees absorb and emit methane, an analysis of precipitation patterns in Australia and their effect on methane uptake in the soil, and research into the effects of grazing patterns on soil health.

Objectives

The objective of the project was to research biological methods for methane capture, to determine sustainable alternatives for reducing methane emissions from livestock in Australia. 

Key findings

The largest methane sinks are the atmosphere, soils, and trees. The largest anthropogenic sources of methane are emissions from ruminants and landfills. In Australia, the troposphere removes approximately 12 Terra gramd per year (Tg/yr) of methane from the atmosphere, and soils are estimated to remove another 2 Tg/yr. Certain species of trees also have the potential to absorb methane from the atmosphere. The largest anthropogenic source of methane in Australia is agriculture, releasing 3-5 Tg of methane per year. Thus, increasing methane sinks by increasing the amount of methane taken up by soils, as well as the amount taken up by plants, could help reduce or store methane emissions from livestock grazing systems.

Because the production and consumption methane from soils occurs as a result of different microbial processes, controlling the factors that influence the growth of microorganisms may help to increase methane uptake from the soil. Numerous factors can affect the growth of methanotrophs and methanogens, including precipitation, soil moisture, soil temperature, soil pH, nutrient availability, and fertilizer. Extremes in any of these cases (acidic soil, poor drainage or nutrient availability, or excessive use of fertilizer) are known to reduce methane uptake in soils.

Benefits to industry

Practical applications to the red meat industry include considering how additions to the soil, such as water and fertilizers, affect the ability of methanogens to uptake methane, as well as altering/timing grazing patterns to take into account soil microbes.

Planting of certain native tree species, as well as engaging in various grazing management practices could also help to increase absorption of methane and carbon dioxide from the atmosphere and soil.

MLA action

MLA is considering investing in further research to better understand the technologies and practices that can reduce net methane emissions in livestock grazing systems.

MLA will support development and adoption activities such as the addition of these practices to Australia’s Carbon marketplace and industry extension adoption activities, to incentivise and encourage producers to engage in methane-reducing and methane consuming practices.

Future research

Future research is necessary to fully understand the most effective biological-based methods and models for methane capture, including: 

• Conducting a "Genius of Place" report on healthy grasslands in Australia and similar biomes. A Genius of Place considers a healthy ecosystem as a whole, looking into the ecology and organisms of a particular place to provide guidance for sustainable design or management.
• An analysis of the benefits of circularizing waste streams, either by identifying how farm waste could benefit other industrial and agricultural streams, or how waste from other industries could benefit the red meat industry.