Atmospheric dust is a global nutrient source for plants via foliar uptake

Atmospheric mineral dust is a critical nutrient supplier to marine ecosystems, but its role in terrestrial plant nutrition remains underexplored due to the assumption that nutrients are acquired solely from soils via roots. Here, we demonstrate that plants directly acquire nutrients from dust through leaves, revealing an unrecognized terrestrial uptake pathway. In a Mediterranean field study simulating dust events, dust application markedly increased plant macro and micronutrient concentrations, facilitated by the mildly acidic, organic-acid-rich leaf microenvironment that enhances dust dissolution and nutrient release. By integrating field observations with dust deposition estimates and soil nutrient data from different regions, we find that annual dust-derived inputs through leaves can account for up to 17% of soil-derived iron fluxes in the Western United States and up to 12% of phosphorus fluxes in the Eastern Amazon. During Mediterranean dust events, daily nutrient inputs can match or exceed soil-derived fluxes. Our findings suggest the major plant nutrition role of foliar dust uptake in nutrient-poor and dust-affected ecosystems. Such a foliar absorption pathway may become increasingly important as dust emissions and transport shift under future climate change and should be accounted for in vegetation, nutrients, and carbon-cycle models.