Exploring the role of soil pore structure in methane emissions from rice paddy fields: A combination of x-ray micro-computed tomography and three-dimensional lattice Boltzmann modeling.

This article investigates how differences in soil pore structure between rhizosphere (root-influenced) and non-rhizosphere soils affect methane emissions in flooded rice fields. Using x-ray micro-computed tomography (mCT) to characterize soil pores and GPU-accelerated three-dimensional lattice Boltzmann method (LBM) simulations to model methane flow, the study found that rhizosphere soils exhibit lower porosity, fewer small pores, larger critical pore diameters, higher connectivity, and lower tortuosity compared to non-rhizosphere soils. These structural differences lead to reduced methane retention and enhanced methane escape in rhizosphere soils. The research highlights the importance of pore size distribution, connectivity, and tortuosity in controlling methane emissions at the pore scale, offering a novel approach to understanding and potentially mitigating greenhouse gas release from paddy soils.