Assessing the Impact of Antecedent Dry Period and Storm Volume on Nitrogen Transport in Biochar-Amended and Compost-Amended Roadway Soils

Roadside soil amendments, like compost and biochar, are used to mitigate the impact of stormwater runoff on the transport of pollutants, like nitrogen, to waterways. However, biochar and compost may leach nitrogen, and the leaching mechanism could be exacerbated by climate change-driven increases to storm volume and antecedent dry period (ADP). Despite this, neither amendment has been evaluated under these climate change scenarios. To properly implement these materials, it is crucial to characterize leachate from biochar-amended and compost-amended soils. The authors compared nitrogen concentrations in outflow from biochar-amended and compost-amended roadside soils following a series of simulated large volume storm events and a series of intermittent storm events with increasing ADPs. First, columns of roadside soil and biochar (30% by volume and 4% by weight) or compost (30% by volume) were irrigated to simulate either a 1 in storm event or 1 year-6 h storm events for Virginia. Then, columns underwent a series of 1 year-6 h storm events with increasing ADPs. Outflow was analyzed for total dissolved nitrogen (TDN). Columns were routinely weighed to gravimetrically track soil moisture. Results indicated that compost-amended soils consistently had the highest effluent TDN concentrations in large storm events and increased ADPs. 30% Biochar by volume consistently had the lowest effluent TDN concentrations in both storm series. All amendments improved soil moisture with 30% biochar by volume having the most significant effect on soil moisture. These results suggest that 30% biochar by volume may be suitable for use as a roadside soil amendment, especially under these increasingly common climate scenarios.

Language

  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Pagination: pp 636-647
  • Monograph Title: World Environmental and Water Resources Congress 2023: Adaptive Planning and Design in an Age of Risk and Uncertainty

Subject/Index Terms

Filing Info

  • Accession Number: 01904049
  • Record Type: Publication
  • ISBN: 9780784484852
  • Files: TRIS, ASCE
  • Created Date: Jan 4 2024 10:48AM