Checking the hype: A data driven approach to assess the effect of conservation measures on water quality in agricultural catchments

Intensification of agricultural production has increased access to food, but puts significant stresses on water quality. Mathematical models of watershed processes are used to guide the management of nutrients, though their use is subject to significant uncertainties. This talk presents a project that uses a data-driven approach to estimate the effect of conservation practices on water quality. While the project focuses on cover crops, it is generalizable to other measures for which spatial data is available. We show that by combining spatial assessments of cover crop extents and stream event sampling with Generalized Additive Modelling, we can estimate the effect of cover crops on different species of nutrient loss. We show that cover crops result in less loss of particulate phosphorus but more loss of dissolved phosphorus with respect to bare fields. We also conduct scenario analyses to evaluate the effects of increased adoption of cover crops on water quality. We conclude with an assessment of data requirements and identify a number of opportunities for applying this approach elsewhere.