Societal impact of reducing nutrient losses from agricultural fields in the Lower Mississippi River Basin: A case study of the Beasley Lake Watershed

Nutrient loading associated with runoff in agricultural watersheds is a problem with societal impacts. Conservation practices on fields within agricultural watersheds significantly reduce nutrient losses to adjacent water bodies. We explore this concept using Beasley Lake, an oxbow lake with a small contributing watershed in the Lower Mississippi River Basin. Since 1996, three conservation practices have been implemented on agricultural lands surrounding Beasley Lake: a vegetated buffer strip (VBS), wildlife habitat established under the Conservation Reserve Program (CRP), and a sediment retention pond. The USDA Agricultural Research Service’s National Sedimentation Laboratory has been actively tracking changes in lake nitrogen (N) and phosphorus (P) in response to practice implementation. Results show a decrease in nitrate and total P (TP) during the monitoring period. Watershed simulations also demonstrated decreases in nutrient loads related to VBS and CRP practices. These nutrient reductions resulted in an estimated environmental damage costs (EDC) decrease of approximately 41,000 – 66,000 USD$ yr -1 . This work impacts society by (i) displaying how best management practices for landscapes can mitigate nutrient loading into waterbodies from agriculture; and (ii) increasing awareness of how best management practices impact EDC associated with nutrient losses and the positive implications of their reduction.