Plants are usually thought to get their nutrients from the ground through their roots. But a new study suggests that is only part of the story. Researchers have found that atmospheric dust can also act as a source of nutrients, with plants able to absorb some of those elements directly through their leaves.
The scientists investigated how dust affects plants under Mediterranean conditions by simulating dust deposition in a field experiment. After dust settled on the leaves, the plants showed increased levels of both macro- and micronutrients. These included phosphorus and iron, two elements that are essential for plant growth and metabolism.
According to the researchers, the surface of the leaf plays an important role in this process. The microenvironment on leaves is slightly acidic and rich in organic acids, which may help dissolve dust particles and release nutrients in a form plants can absorb. In other words, leaves are not just passive surfaces collecting material from the air — they may actively help process atmospheric particles and take up useful minerals.
The team then compared their field results with global estimates of dust deposition and soil characteristics. They found that this kind of “leaf feeding” could make a meaningful contribution in some regions. Their estimates suggest that, in the western United States, iron absorbed through leaves could account for as much as 17% of the iron plants normally receive from soil. In the eastern Amazon, phosphorus from dust could provide up to 12% of the soil-derived phosphorus supply. During major dust events, daily nutrient input through leaves may even match or exceed what comes from the soil.
These findings suggest that the traditional view of plant nutrition — focused almost entirely on roots and soil — may need to be expanded. Plant canopies may serve as an active interface between ecosystems and the atmosphere, capturing dust and extracting nutrients from it. This mechanism could be especially important in nutrient-poor environments or in regions that regularly experience dust transport.
The authors also note that this process may become even more important in the future. Climate change could alter the amount of dust in the atmosphere and the way it moves around the planet, potentially affecting how plants receive key nutrients. Because of that, the researchers argue that foliar nutrient uptake from dust should be taken into account in models of vegetation, nutrient cycling, and the carbon cycle.
In simple terms, plants may not be feeding only through their roots. When mineral-rich dust lands on their leaves, they may be able to “eat” through their foliage too — and that pathway could be far more important than scientists once thought.