Enhanced rock weathering increases crop yield: a global meta-analysis

Abstract Enhanced rock weathering (ERW) is increasingly considered for CO₂ removal on agricultural land, yet its effects on crop productivity remain uncertain across crops, soils and amendment practices. This work is the first global meta-analysis of experimental evidence published between 1983 and 2026, comprising 7,236 treatment-control comparisons from 113 publications. Of these, 2,086 comparisons from 52 publications were eligible for multilevel random-effects meta-analysis with publication-clustered robust inference. ERW increased harvested yield by 29.0% (95% CI: 8.7–53.1%; 22 publications, 91 comparisons), shoot dry biomass by 16.1% (95% CI: 8.6–24.2%) and aboveground potassium uptake by 36.5% (95% CI: 26.7–47.0%). However, the publication-balanced median harvested-yield increase was 14.8% across the broader evidence base, and substantial heterogeneity produced a wide prediction interval (-43.4% to + 194.0%). Crop-specific responses varied, while exploratory moderator analyses did not establish reliable predictors of agronomic effectiveness across soil conditions, climates, rock materials or application practices. Strictly matched experimental responses revealed a positive association between potassium uptake and harvested yield (Spearman's ρ = 0.905; adjusted q = 0.008), although the limited evidence and potential mathematical coupling preclude causal interpretation. Overall, ERW can improve agricultural productivity, but the magnitude and consistency of these benefits remain context-dependent. Agronomic performance should therefore be evaluated independently of CO₂ removal, with greater emphasis on replicated field experiments and concurrent measurements of crop productivity, nutrient acquisition and soil conditions.