Volcanic ash as multi‐nutrient mineral fertilizer: Science and early applications

Volcanic ash is a multi-nutrient mineral fertilizer whose catalytic mechanism of action, replenishing trace metals are necessary for soil bacterial enzymes for the efficient biogeochemical cycling of key elements, such as N, C, P, and S, ensures use of relatively small amounts to fertilize large soil surfaces. Chiefly demonstrated in the course of the 2010 s in Russia's Kamchatka and in Indonesia, two world's areas hosting highly active volcanoes, these findings remain poorly known. Fulfilling the principles of the emerging circular economy, the large-scale use of readily available and overabundant tephra as agricultural fertilizer is a significant economic opportunity for both farmers and populations living near active volcanoes, affording also important environmental advantages. Providing a unified picture, this study will hopefully accelerate such progress.