Multi-Layered Approaches to Mitigating Agricultural Nutrient Surpluses in a Peri-Urban Region.

The Lower Fraser Valley in south coastal British Columbia, Canada, typical of urban/peri-urban regions worldwide, receives large amounts of nutrients as organic and mineral products for meeting the needs of its intensive agricultural production and large human population. There are currently inadequate technologies that are both effective and inexpensive to help curtail the agricultural nutrient surpluses. Furthermore, technologies often target relatively narrow issues such as reducing emissions of ammonia. In this presentation we will describe novel multilevel mitigation strategies to address overarching issues such as nutrient surpluses. The strategies include: 1. innovative agronomic practices on dairy farms for exploiting both N and P from separated slurry, 2. complimentary cropping systems for grass and corn to better meet animal feed requirements, 3. multi–sector manure swapping for environmental harm reduction of farm nutrients, and 4. enhanced nutrient and energy flows between the rural and urban ecosystems. As all of these strategies are meant to be practical and low cost, their impacts are inherently incremental however, in concert, they can bring about substantive improvements to regional nutrient sustainability for both food production and consumption.