Linkages Among C, N and Water Footprints in Wheat-Based Cropping Systems.

Soil C, N and water cycles and flows are intimately linked in wheat-based agroecosystems of the Pacific Northwest.  Regionally, landscape and soil properties are strong agroecosystem drivers that modify climatic and economic determinants at the field scale. We discuss research, education and outreach conducted during the last 13 years at the WSU Cook Agronomy Farm (CAF) that explores landscape, soil and cropping system (rotation and tillage) interactions and influences on soil C and N cycling, soil C sequestration, and N and water use efficiencies. Soil and water data are derived from 369 geo-referenced points established on the 37-ha CAF in 1999. Measurements including the use of stable  isotopes have continued through the present at different temporal and spatial scales that quantify linkages among C, N and water footprints. The field-scale CAF research is highly relevant to growers, producer groups and students serving as an outdoor laboratory for class field trips as well as field days.  Research, education and outreach efforts at the CAF have been supported by the strong partnership among land grant Universities (WSU, U of I) and the USDA-ARS with funding from an NSF IGERT project entitled "Nitrogen Systems: Policy-oriented Integrated Research and Education (NSPIRE)" and three USDA NIFA funded projects: a planning grant for Long-term Agricultural Practices (LTAP); a NIFA CAP project entitled "Regional Approaches to Climate Change (REACCH)"; and a standard NIFA project entitled "Site-Specific Climate Friendly Farming (SCF)". In addition, the CAF has recently been selected by the USDA-ARS as one of ten initial sites for a Long-Term Agroecosystem Research (LTAR) network in the US. These efforts are key to the development of agricultural concepts and strategies with respect to multifunctional landscapes, precision agroecology and more sustainable agricultural systems.