Shifting the paradigm for phosphorus fertilization in the advent of the fertilizer crisis

Abstract

Crop production and food security will be challenged by the availability of phosphate rock and its derived phosphorus (P) fertilizers in the coming decades. Croplands around the world have traditionally received huge amounts of P fertilizers. However, P can quickly become unavailable in soil due to its fast adsorption or fixation on the surface of soil particles. Here, we propose the use of microbially mediated mechanisms of soil-borne populations to solubilize historically accumulated P over years. We argue that microbially mediated solubilization of P can be enhanced through elemental imbalances that intentionally alter the soil carbon:nitrogen:P ratio, enabling a greater P demand by some soil microbial populations. This strategy may potentially reduce our dependence on conventional and exhausting P fertilizers, but the main caveats are also discussed.