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 to the assumption that nutrient acquisition occurs predominantly through root uptake from soils. Here, we present evidence from controlled greenhouse experiments under ambient and elevated CO₂, laboratory simulations of leaf microenvironments, isotopic and geochemical tracing, and field fertilization experiments conducted in both a Mediterranean ecosystem and a tropical forest in Puerto Rico, demonstrating that plants can directly acquire nutrients through their leaf surfaces following atmospheric dust deposition. Using rare earth elements and Nd isotopes, we distinguish nutrients derived from soils from those delivered by deposited atmospheric particles. Laboratory simulations show that mildly acidic leaf surfaces, together with organic acids secreted by leaves, enhance mineral dissolution and facilitate foliar uptake of dust-borne nutrients. In a pioneering Mediterranean field experiment explicitly designed to isolate foliar uptake, we quantified the bioavailable fraction of key nutrients supplied by dust, including P, Fe, Mn, and Cu, and observed clear enrichment of multiple micronutrients in leaf tissues following dust application. These field-based measurements enabled the construction of a global geospatial framework integrating dust deposition with soil nutrient fluxes, indicating that dust-derived inputs can constitute a meaningful fraction of total nutrient supply across large regions, and that during dust events, short-term foliar inputs can rival or exceed soil-derived fluxes. Complementary field observations in a tropical forest in Puerto Rico further reveal foliar nutrient responses consistent with direct dust uptake. Building on these results, we outline a pathway for incorporating foliar dust uptake into Earth system representations of terrestrial nutrient cycling by explicitly accounting for atmospheric nutrient inputs at the canopy level and their interaction with soil-derived fluxes. Together, these findings identify foliar dust uptake as an overlooked but consequential nutrient acquisition pathway and highlight its relevance in highly weathered, nutrient-limited tropical forests, where atmospheric inputs may play a critical role in regulating nutrient availability and carbon–nutrient interactions.
