This introduction presents background information on agricultural water quality problems in the Cornbelt, as well as discussion of the institutional framework within which these water quality problems are currently managed. Information is given on the key pollutants, their sources, and the range of conservation methods that can attenuate their effects. We also describe the Total Maximum Daily Load process and cove a range of federal and state conservation programs that provide funding for voluntary conservation efforts.

This "tale of three watersheds," illustrates how conservation practices must be tailored to individual landowner objectives and local landscape conditions in order to optimize their effectiveness. Based on research conducted as part of USDA's Conservation Effects Assessment Project and its Watershed Assessment Studies paper arises from a project that evaluated the effects of agricultural conservation practices on water quality. Project focus involved improving the understanding how the suite of conservation practices, the timing of these activities, and the spatial distribution of these practices throughout a watershed influence their effectiveness.

Due to numerous inter–linkages in natural ecosystems, the development of an ecosystem credit market that provides one ecosystem service may significantly change the level of provision of other ecosystem services. In this paper, the authors consider the possible water quality consequences of a carbon trading policy that allows farmers to receive carbon credits from retiring their land from agricultural production.

Several technologies can remove nitrates directly from water and are employed by municipal water works in order to comply with drinking water standards during periods of high nitrate concentrations in source water. These technologies are costly to operate, suggesting an opportunity for cost savings via upland reductions of fertilizer application. This article explores possible tradeoffs in the context of a nutrient–application–right trading scheme in the Raccoon River Watershed in Iowa.