United States Department of Transportation
i
Understanding the Effects of Slope Ratio, Straw Mulching, and Compost Addition to Topsoil to Establish Permanent Vegetation and Reduce Nutrient Runoff
-
2020-05-01
[PDF-1014.60 KB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:SPR-B Final Report, (February 2019-April 2020)
-
Corporate Publisher:
-
Abstract:Soil erosion management is a major environmental challenge facing highway construction. This project analyzes sustainable improvements to current standard procedures for final grade turfgrass establishment on disturbed soils. Using a series of greenhouse studies, two compost types, biosolids and greenwaste, and four compost/topsoil blends were compared with a standard topsoil/straw/fertilizer practice in their ability to reduce soil and nutrient loss and improve the rate, quality, and quantity of green vegetation (GV) establishment. These studies also observed the effects of slope ratio changes and additional straw mulching to composted media. At a 25% slope, straw mulching significantly reduced runoff quantity and improved quality as well as GV cover. On average, straw mulching reduced mass export of nutrients and sediment by 86-91% on tested media. With mulching, no statistical differences were found in the rates of vegetation growth among the compost-amended slopes (all reached >95% cover in 60 days), however, without straw mulching maximum GV cover after 60 days was 31%. Straw mulching with the addition of composted material (excluding 50% compost: topsoil) reduced the total runoff volume (13-59%), sediment mass (64-98%), and nutrient mass (6-82% nitrogen and 4-76% phosphorus) from topsoil application. Observations made for media tested at various slope ratios showed a general increase in nutrient and sediment export with slope ratio increase. Also, the volume, sediment and nutrient export reductions displayed at the 25% slope were less evident at shallower slopes and enhanced at greater slopes.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
