Phosphorus (P) in animal diets as a driver of embodied P in animal products and net anthropogenic P inputs

One approach to address both the environmental and scarcity issues that occur with phosphorus (P) losses from human systems is to improve understanding of the P demands of bio-based products. Most P demand in the United States is driven by production of crops for animal feed and mineral P feed supplements for animals. In this research, we used the Commodity-Specific Net Anthropogenic Phosphorus and Nitrogen Inputs (CSNAPNI) model to (1) assess the contributions of individual feed products such as corn, soy, and mineral P supplements to the embodied P of animal products and (2) estimate net anthropogenic phosphorus inputs (NAPIs) for the contiguous United States for two animal P-intake scenarios. Results show that P supplements may contribute up to 30% of embodied P in pork and dairy products, up to 60% in chicken, and up to 75% in turkey. Other major contributors to animal product-embodied P are grains, which are responsible for around 60% of embodied P in pork and dairy products, at least 30% in chicken, and at least 20% in turkey products. Results also show that animal P intake is such a significant driver of anthropogenic phosphorus that a reduction of animal P intake by 25% could reduce NAPI to the contiguous United States by 30%. Considering promising research on methods to improve digestibility of both mineral P supplements and grain P in animal diets, these results are encouraging.