Location: Meat Safety and Quality
Title: Modeling the effects of land use and agricultural management on nutrient loss, atrazine and E. coli concentrations in a watershed using SWATAuthor
ABIMBOLA, OLUFEMI - University Of Nebraska | |
MITTELSTET, AARON - University Of Nebraska | |
MESSER, TIMMANY - University Of Nebraska | |
Berry, Elaine |
Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only Publication Acceptance Date: 2/25/2019 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Excess nutrients and herbicides remain two major causes of waterbody impairment globally. In an attempt to better understand pollutant sources in the Big Sandy Creek Watershed (BSCW), and the prospect for successful remediation, the Natural Resources Conservation Service (NRCS), Nebraska Department of Environmental Quality (NDEQ) and Little Blue Natural Resources District (LBNRD) initiated a program to assist agricultural producers with the implementation of best management practices (BMPs). Owing to the high cost of water-quality monitoring at field and subwatershed scales, simulation models provide a cost-effective approach for assessing the performances of targeted BMPs to hotspots and for determining potential water-quality improvements with the adoption of these BMPs. This study aimed to apply the hydrological model Soil and Water Assessment Tool (SWAT) to simulate BMPs within the BSCW to determine the reduction of atrazine, E. coli, sediment, phosphorus and nitrogen after BMPs are implemented. The predicted impacts of five BMPs on nutrients, atrazine and E. coli reduction at reach and subwatershed scales in three targeted hotspots were evaluated. These BMPs were no-till, cover crop, filter strip, crop rotation and atrazine application reduction. The model was set up for the BSCW using long-term spatial and temporal datasets from 1989 to 2016. The SWAT model was calibrated and validated from 2004 – 2016 and 1994 – 2003, respectively for flow, sediment, total nitrogen (TN), total phosphorus (TP), atrazine and E. coli. Results predicted filter strip to be the most effective BMP in reducing nutrients and E. coli in the hotspots while reducing application rate by 50% was the most effective BMP for atrazine reduction. A combination of these two best BMPs is most likely to yield measureable improvement in the targeted reach segments of the watershed. |