Reducing Sediment and Phosphorus Runoff Losses in Livestock Settings using Slag/Biochar Bioreactors

Abstract Submission: Advancements in bioreactor technology have allowed for the development of new methods to reduce excess nutrients from agricultural runoff, utilizing co-product materials like slag and engineered biochar in unique combinations. A field study has been implemented to quantify the impact of bioreactor installation on runoff and in-stream processes in a livestock setting in Mississippi. Bioreactors were installed using 4-inch slag as a grade stabilization structure in head-cutting gullies that were then backfilled with engineered biochar designed to adsorb phosphorus from pasture stormwater runoff. Water samples were collected upstream and downstream from 6 replicates of bioreactor, grade-stabilization-only, and control treatments. Study findings show that the bioreactor design reduces the amount of phosphorus reaching the main channel of the stream when compared to grade-stabilization and control treatments. The bioreactors' effectiveness in removing phosphorus from runoff is extended over two years, allowing for the gullies' stabilization. Results have been transferred to producers in the Redbud-Catalpa watershed, the state of Mississippi, and the southeastern US via field days, information sheets, conference presentations, and outreach events.

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