Integrated Vegetation Management Along Alaska’s Highways

Abstract and project information last updated: 1 March 2011. Project updates are dated below.

AUTC
Project
Number
107024
Principal
Investigator
David L. Barnes (UAF)
dlbarnes@alaska.edu
Funding
Agency

US Department of Transportation (RITA)

Alaska Department of Transportation & Public Facilities

Project
Budget
213032
Start
Date
1 April 2007
Estimated
End Date
30 June 2008

Abstract

This project worked with AKDOT&PF, the USDA Agricultural Research Service (Subarctic Agricultural Research Unit), and the Salcha-Delta Soil & Water Conservation District to develop an integrated plan for roadside vegetation control. The most salient study results concern the half-lives determined for each herbicide sample collected from the Delta Junction test site. Samples obtained up to 27 days (prior to an increase in herbicide concentration found in the soil following a relatively large rain event) after application indicate that the attenuation rates are similar to rates reported in the literature for more temperate soils.

Further, both 2,4-D and triclopyr are found in the soil at some concentration one year after application, indicating that herbicide persistence is longer compared to reported results from more temperate regions.Researchers also found that the percentage of herbicide mass measured at each sampling event compared to the mass applied was small and relatively consistent for each site through the course of the study. Our conclusion is that plant uptake and metabolism play a key role in the attenuation of herbicides applied to subarctic soils.