An Improved Laser-Diffraction Analysis-Based Approach on Soil Aggregate Stability: a New Factor Governing Soil Methane Uptake

Methane (CH4) is a potent greenhouse gas contributing to climate change, with a global warming potential of 24x of CO2 on a 100-year time-frame. More importantly, the atmospheric methane concentration has been rising rapidly in the last decade. Soils are as yet the only known biological sink for atmospheric methane, but the methane uptake capacity of agricultural soils is substantially reduced when compared to native soils. This may be due to a reduction of soil organic matter and soil aggregate stability as a result of agricultural management practices. In this study, we improved a laser-diffraction analysis-based modelling of soil aggregate stability. Using data from an extensive field study, we show new relationships between soil aggregate stability, atmospheric methane uptake, and soil organic matter. The use of organic amendments like compost increases soil organic matter content, which improves soil aggregate stability, and in this study, we show that an improved soil aggregate stability enhances atmospheric soil methane uptake. These results provide new insights on the use of organic amendments like compost on agricultural soils as an atmospheric methane mitigation strategy.