A Soy Protein Substitute for Animal Meat Proteins Can Provide Global Phosphorus Reduction and Recirculation Opportunities

Animal meat protein consumption is typically associated with environmental impacts greater than those of plant-based proteins. While most environmental impact assessments comparing animal- and plant-based proteins focus on water usage and carbon emissions, phosphorus (P) use is a key parameter for a sustainable food system. Country-specific animal and crop parameters were leveraged to evaluate the P footprint of current animal meat protein consumption and potential benefits from substitution using soy-based protein. The global average P footprint for animal meat protein consumption when considering synthetic and manure P fertilizers was an estimated 2.6 kg P year^-1 per capita in 2019. A complete transition to soy protein concentrate (SPC) from animal meat protein was estimated to decrease total P fertilizer applied to animal feed products by 81%, or an estimated 8.3 million metric tons of P per year and 33% of the total estimated 2019 P fertilizer utilization. Additionally, the recovery of P during SPC processing could generate sufficient renewable P fertilizer to replace an estimated 17% of the total P utilized in global soybean production. The reduction and efficient reuse of P from a transition to SPC as a primary protein source can generate greater security and resiliency in global food systems.