Beyond roots: Foliar dust as a vital nutrient source for plants under elevated CO2

While roots have long been considered the sole pathway for plant nutrient uptake, a surprising discovery reveals a hidden source: foliar dust. This study demonstrates that plants can directly acquire crucial minerals like P, Fe, and Ni from deposited dust particles, bypassing the root system altogether. In our experiments, we had applied two types of dust on plant foliage and examined biomass, P content, and ionome. Remarkably, utilizing radiogenic Nd isotopes, we show that this foliar pathway surpasses root uptake in just weeks, contributing over 60% of a plant's nutrient profile under elevated CO2 conditions.

These findings shed light on a previously unrecognized adaptation that could be critical for plant survival in a CO2-rich world. As eCO2 levels are predicted to decrease soil nutrient availability, the dust-as-nutrient phenomenon offers a potential lifeline for plants and ecosystems. Moreover, understanding this alternative pathway could pave the way for novel agricultural strategies to combat "hidden hunger" malnutrition triggered by CO2-induced nutrient deficiencies.