Atmospheric mineral dust is a well-established source of nutrients to marine ecosystems,yet its contribution to terrestrial plant nutrition has long been underestimated, largely due tothe assumption that nutrient acquisition occurs predominantly through root uptake fromsoils. Here, we present evidence from controlled greenhouse experiments under ambientand elevated CO₂, laboratory simulations of leaf microenvironments, isotopic andgeochemical tracing, and field fertilization experiments conducted in both a Mediterraneanecosystem and a tropical forest in Puerto Rico, demonstrating that plants can directlyacquire nutrients through their leaf surfaces following atmospheric dust deposition. Usingrare earth elements and Nd isotopes, we distinguish nutrients derived from soils from thosedelivered by deposited atmospheric particles. Laboratory simulations show that mildlyacidic leaf surfaces, together with organic acids secreted by leaves, enhance mineraldissolution and facilitate foliar uptake of dust-borne nutrients. In a pioneering Mediterraneanfield experiment explicitly designed to isolate foliar uptake, we quantified the bioavailablefraction of key nutrients supplied by dust, including P, Fe, Mn, and Cu, and observed clearenrichment of multiple micronutrients in leaf tissues following dust application. These fieldbasedmeasurements enabled the construction of a global geospatial framework integratingdust deposition with soil nutrient fluxes, indicating that dust-derived inputs can constitute ameaningful fraction of total nutrient supply across large regions, and that during dustevents, short-term foliar inputs can rival or exceed soil-derived fluxes. Complementary fieldobservations in a tropical forest in Puerto Rico further reveal foliar nutrient responsesconsistent with direct dust uptake. Building on these results, we outline a pathway forincorporating foliar dust uptake into Earth system representations of terrestrial nutrientcycling by explicitly accounting for atmospheric nutrient inputs at the canopy level and theirinteraction with soil-derived fluxes. Together, these findings identify foliar dust uptake as anoverlooked but consequential nutrient acquisition pathway and highlight its relevance inhighly weathered, nutrient-limited tropical forests, where atmospheric inputs may play acritical role in regulating nutrient availability and carbon–nutrient interactions.
