Upstream Flux of Phosphorus to Household Food Systems

Phosphorus is not only a non-renewable resource that is being globally depleted, but is also an essential nutrient for agricultural production. Research has indicated that the most direct contributor to the flux of P into the urban ecosystem is human diet. Once consumed, nearly all of that P leaves the household as wastewater, often leading to impairment of our water resources.

The purpose of this study is to examine how the total upstream flux of P within the state of Minnesota is influenced by Twin Cities household’s dietary food choices. Findings from this research will help identify the most nutrient intensive dietary food items, thereby influencing future household food choices. Future research will attempt to identify nutrient efficiencies within food systems.

For more information about the study, please contact Dr. Heidi Peterson ( or Dr. Larry Baker (


Food consumption for the population of Minnesota and the Twin Cities Metropolitan Area (TMCA) was estimated using the 2007-2008 USDA National Health and Nutrition Examination Survey and extrapolating data based on 2000 Census data for age, gender and race.

Nutrient flux spreadsheets are currently being constructed by compiling research on agricultural production systems. This compilation includes, with respect to livestock, the incorporation of herd structure, manure production, feed composition and nutrient requirements. For cropping systems the spreadsheets consider fertilizer and manure application rates and nutrient composition, crop yield and crop use (i.e. feed, industry, residual).

Analysis and Results

Research results will be completed and published in the fall of 2012.