Plants Can Feed on Dust in the Air

According to SAEDNEWS, billions of tons of dust are lifted from the Earth’s surface every year and transported by wind across continents and oceans. Scientists have long known that this dust plays an important role in soil formation and in delivering essential nutrients to ecosystems. Dust particles often contain valuable minerals such as iron, phosphorus, and potassium—elements that are essential for plant growth.

However, most previous research has focused on the role of dust in enriching soil. A new study suggests that plants may have another way of using these minerals: direct absorption through their leaves.

To investigate this, researchers conducted a field experiment in a natural area that receives large amounts of mineral dust each year. In the experiment, they sprayed volcanic dust onto the leaves of three common shrub species. The dust had a composition different from the local soil, allowing researchers to determine whether minerals entered the plants through leaves rather than roots.

The results showed that levels of certain micronutrients such as iron, manganese, nickel, and copper increased in the above-ground parts of plants exposed to dust, while root levels remained almost unchanged. This indicates that minerals were directly absorbed through the leaf surface.

Researchers then combined field data with estimates of dust deposition around the world. The results suggest that foliar dust absorption can play a significant role in plant nutrition in some regions. For example, it may provide up to 17% of annual iron needs for plants in the western United States and up to 12% of phosphorus needs for plants in the eastern Amazon.

But how do plants extract minerals from dust? When dust particles settle on leaves, the leaf surface creates a slightly acidic environment. Plants secrete specific organic acids that help dissolve minerals, converting them into a soluble form so they can be absorbed.

Researchers also highlighted the role of tiny structures on leaves. Some plants have microscopic hair-like structures called trichomes. These structures usually help reduce leaf temperature, reflect sunlight, and reduce water evaporation.

The new study suggests that trichomes may also serve another important function: trapping dust. These tiny hairs can hold dust particles on the leaf surface, giving minerals more time to dissolve and be absorbed.

These findings could change scientists’ understanding of nutrient cycles in nature, especially in dry and nutrient-poor regions where dust plays a major ecological role. They also show that atmospheric dust can be more than just a factor affecting air quality or climate—it may be an important part of plant nutrition in many parts of the world.