Impact of stacked conservation practices on phosphorus and sediment export at the catchment scale
Law, Ji Yeow
Long, Leigh Ann
Best management practices (BMPs) are effective in reducing nutrient and sediment export, but further understanding of the benefits of the stacked BMPs is needed. This catchment‐scale study was established to evaluate the impact of hydrology and BMPs on phosphorus and sediment losses. Two adjacent catchments, one with a lower (Low‐BMP #11) and one with a higher level of BMP adoption (High‐BMP #12), were compared for total phosphorus (TP) and total suspended solids (TSS) export. The BMPs include nutrient management plans, reduced tillage, grassed waterways, terraces, and perennial vegetation. The TP‐event‐flow‐weighted (EFW) concentration was significantly higher at Low‐BMP #11 (0.293 mg L−1) than at High‐BMP #12 (0.069 mg L−1). There was no significant difference in TP‐base‐flow‐weighted (BFW) concentrations between Low‐BMP #11 (0.035 mg L−1) and High‐BMP #12 (0.037 mg L−1). The TSS‐EFW (148.0 vs. 18.6 mg L−1) and TSS‐BFW (13.3 vs. 6.9 mg L−1) concentrations were also higher at Low‐BMP #11 than at High‐BMP #12. High‐BMP #12 had lower TP (0.36 vs. 0.59 kg ha−1 yr−1) and TSS (253 vs. 1961 kg ha−1 yr−1) loading than Low‐BMP #11. The lower TP export at High‐BMP #12 was likely attributed to the effectiveness of stacked erosion control BMPs and nutrient management plans. Overall, lower phosphorus and sediment loading was observed when a greater areal extent of stacked practices were implemented at the catchment level. This finding provides vital information to encourage wider BMPs adoption at the watershed scale.
This is the peer-reviewed version of the following article: Law, Ji Yeow, Conrad Brendel, Leigh Ann Long, Matthew Helmers, Amy Kaleita, and Michelle Soupir. "Impact of stacked conservation practices on phosphorus and sediment export at the catchment scale." Journal of Environmental Quality (2020), which has been published in final form at DOI: 10.1002/jeq2.20140. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Posted with permission.