What it is
Enhanced weathering, spreading crushed silicate rock like basalt on farmland so it dissolves and captures CO2, is a promising durable carbon-removal route, but field trials have mostly inferred removal rather than observed it directly. This study applied continuous in-soil CO2 monitors, a method not previously used in agricultural enhanced-weathering trials, to a basalt-amended soybean plot in southeast Virginia. The monitors captured a reduction in the soil CO2 flux equivalent to 1.04 tCO2 per hectare per year. The removal was strongest during the growing season and followed significant rain pulses.
Why it matters
Carbon-removal buyers and standards need measurement they can trust, and enhanced weathering's central weakness has been verifying how much CO2 a field actually captures rather than modeling it. Directly and continuously observing a removal of 1.04 tCO2 per hectare per year from gas-phase soil measurements addresses that measurement-and-verification gap head on. The rain-pulse dependence also gives a mechanistic handle on when and why dissolution accelerates, which matters for designing and crediting real deployments.
Underlined numbers link to their source. Every metric and quoted figure is listed under Sources and data below.
Filed underenhanced weathering, carbon removal, basalt, measurement and verification, agriculture