Improved methane mitigation potential and modulated methane cycling microbial communities in arable soil by compost...

Area of Science:

• Agricultural Science
• Environmental Science
• Microbiology

Background:

• Rising atmospheric methane (CH4) concentrations, a potent greenhouse gas, are largely driven by agriculture (30%-50% of annual emissions).
• Effective methane mitigation strategies are crucial for limiting global warming.
• Organic amendments, such as compost, show promise for methane mitigation in laboratory settings.

Purpose of the Study:

• To investigate the impact of organic amendments on methane mitigation potential in agricultural soils through a field study.
• To analyze the effects of organic amendments on methane-cycling microbial communities in arable soils.

Main Methods:

• Conducted an extensive field study on arable soils treated with organic amendments.
• Assessed methane (CH4) oxidation rates and potential.
• Characterized methanotrophic and methanogenic microbial communities using molecular techniques.

Main Results:

• Organic-amended soils exhibited increased methane (CH4) uptake rates and enhanced oxidation capacity.
• Compost application altered soil microbial communities, increasing the abundance of specific methanotrophs and methanogens.
• While compost introduced specific microbes like *Methylocaldum szegediense* and *Methanosarcina horonobensis*, conventional type IIa methanotrophs were also implicated in improved CH4 uptake.

Conclusions:

• Compost acts as a vector for introducing methane-cycling microbes into agricultural soils.
• Organic fertilization with compost enhances soil's capacity to mitigate methane (CH4) emissions.
• This highlights the potential of compost application as a sustainable strategy for agricultural methane reduction.