Best Management Practices Effectiveness on Stream Water Quality in Livestock Management Areas

Abstract

Losses of soil, nutrients, pesticides, pathogens and other biological and chemical materials from agricultural lands can be reduced through implementation of conservation plans and implementation of conservation practices otherwise known as Best Management Practices (BMPs) (Sotomayor-Ramirez et al., 2008). This study evaluates the pre- and post-implementation effects of a set of Best Management Practices on the variation of stream health and water quality along the reach flowing through the Mississippi State University Dairy Farm. The BMPs include livestock stream-crossings and riparian zone planting/fencing. Water quality monitoring consisted of bi-weekly grab sampling and in-situ testing from July 2019 to March 2022. Results indicated poor water quality conditions during the pre-implementation period. Concentrations of total phosphorus (TP), total nitrogen (TN) and total suspended solids (TSS) increased along the study reach, which did not meet nutrient criteria for streams in Mississippi. Water quality impairments were influenced by upland land use activities, direct access of cattle to the stream, and sediment supplied from actively eroding streambanks. Post-implementation results indicated that BMPs significantly (p=0.05) improved stream water quality, reducing nutrient and sediment concentrations. Despite reductions, TP and TN concentrations remained above established nutrient criteria (Figure 1). <fig><graphic xlink:href=23201_files/23201-00.jpg id=ID_728624eb-c0b7-4c8a-ac8a-03eea9880c99></graphic></fig> The removal efficiency in summer, fall and winter were respectively, 48%, 39%, and 42% for TSS; and 17%, 31%, and 32% for TN. TP concentrations decreased by 18% in the summer and fall, but increased by 19% during the winter. Reductions in stream water temperature and increases in dissolved oxygen levels suggested a positive shading effect on water quality. Reductions in pH and turbidity demonstrated the success of the BMPs in mitigating the impact of the livestock management area. Overall, despite the partial effectiveness of the BMPs, additional conservation practices above the Dairy Farm land are needed to accomplish the desired water quality criteria for the attained use for the stream<b>.</b>