Sustainable Phosphorus Use in Agriculture

Phosphate fertilizers are continuously used in agriculture around the world to supply plant demands and overcome the competing action of soils for phosphorus (P) adsorption. In some regions, the amount of P applied via organic or mineral fertilizers over the decades has saturated the adsorption sites. This additional P in the soils increases its susceptibility to losses and reduces the plant’s ability to take up the required micronutrients, further promoting environmental problems. In these high-P soils, if water-soluble P or sediments are transferred to water bodies by runoff/erosion, the consequent water eutrophication can cause concerns to water quality, and aquatic flora and fauna. Although well-known, the economically viable phosphate rock mines are finite and it is a non-renewable resource that will eventually vanish. Agricultural systems need to be more efficient in P use, producing more with less, for a better balance between inputs and outputs of P and to postpone a future scenario of scarcity. Management systems that can reach 80-90% of P-use efficiency are achievable in some regions of the world, as demonstrated by previous research. While current management systems rarely reach 40-50% P-use efficiency, we must establish more sustainable systems to prevent future agricultural loss.

To improve the P efficiency of cropping systems, many strategies can be adopted, including: readjusting fertilizer recommendations, use of crop rotations to explore distinct soil regions/volumes as well as P-mobilizing species, intensifying the use of wastes and by-products, adoption of best management practices, and continuous revision of environmental regulations to avoid excessive accumulation of P in the soil. Engineering of plants, fertilizers, and microorganism processes are also needed, as the development of P-efficient cultivars, novel fertilizers with enhanced efficiency, and stimulating beneficial associations between plants and microorganisms can all extend the root system or mobilize P in the rhizosphere. All these strategies can improve the P use from soil/fertilizers and contribute to a more balanced phosphate input/output in agriculture.

In this Research Topic, we invite soil/plant scientists to submit studies reporting recent advances on various aspects of improvement in P use in cropping production systems, including quantitative and qualitative methods and indexes for measuring it, sustainable management of P fertilizers, more efficient phosphate sources, strategies of plants/microorganisms to mobilize and better P use in soils, and soil management practices that may be profitable for more sustainable P use. We will accept the submission of Original Research articles, Review or Systematic Reviews, Policy and Practice Reviews, Perspectives, Opinions, Meta-analysis, Methods, and Data Reports.