Anand et al. (2026): Soil Structure and Mixing Controls on Water-Rock Contact: Implications for Enhanced Weathering
Shashank Kumar Anand, Matteo Bertagni, Felipe Aburto and Salvatore Calabrese, IN: Water Resources Research, https://doi.org/10.1029/2025WR041479
Enhanced weathering (EW), the addition of finely ground silicate rock powder (RP) to soil, has emerged as a promising carbon removal strategy. However, quantifying weathering rates in soils remains challenging, as most continuum-scale EW models do not adequately account for the fraction of RP surface area (SA) that is wet at a given soil moisture and thus actively weathering. Here, the authors study how soil pore structure, RP particle size distribution, and RP mixing degree within the soil control water-rock contact. Using a soil-physics-based framework, they derive a scaling factor that quantifies the wet fraction of RP SA as a function of soil moisture and mixing degree within soil pores.