Linking agricultural conservation to water quality outcomes in the United States at multiple scales: Do we have the information we need?

Excess nitrogen and phosphorus export from agricultural lands is a primary contributor to water quality degradation in the United States. To improve water quality, significant investments have been made to implement conservation practices on agricultural lands, including through mandated spending in the Farm Bill and the Inflation Reduction Act. Effectively guiding conservation implementation requires assessment of practice efficacy at regional and national scales, consistent with the scales of water quality goals. To evaluate whether existing resources are sufficient for such conservation efficacy assessments, we review prior efforts and publicly available data and tools to evaluate the effects of agricultural conservation on water quality outcomes. We find that practice records from programs that fund agricultural conservation have a unique and substantial potential for secondary use to generate insights about conservation effects from local to national scales, but modifications would help maximize the potential of these data for assessing conservation efficacy. Such assessments would benefit from improved consistency in reporting units and geographic scales across program datasets; quantification of the duration of water quality benefits from conservation practices; publication of practice data aggregated across programs, to increase the spatial resolution of conservation insights while maintaining legal protections of producer privacy; and collection of water quality and conservation practice data at similar temporal and spatial scales. Enhancing existing and future datasets could deliver high return on effort by generating valuable insights to improve the use of conservation practices for water quality management.