Understanding landscape scale controls on groundwater quality: How does participatory investigation help to address environmental problems associated with land management?

Rising levels of nitrate in groundwater across the US endanger human and ecological health and are associated with increasing agricultural fertilizer application. Yet increasing N fertilizer use is also a response to decreased soil fertility with duration of cultivation in many former grassland ecosystems. Costs of N fertilizer now figure strongly in the economics of contemporary food production, in the context of global markets that dictate prices and consequently the economic and environmental health of local communities. In the Judith River watershed of central Montana, high nitrate levels in domestic wells pose multiple challenges for communities whose economies depend on dryland cereal production. Our participatory work with local producers seeks to identify both sources of groundwater nitrate and management practices that contribute to nitrate leaching from soils. Active and ongoing collaboration between producers and a multidisciplinary team of university researchers has led to unexpected insight about both controlling processes on the landscape, and ways to investigate and identify causes and solutions for increased sustainability of human food production