Compost use for erosion control
DOT roadside and construction
Compost use: roadside vegetation and highway construction
Soil incorporation is an effective compost use for any type of construction project, whether the objective is erosion control during construction or simply establishing a healthy stand of vegetation for long-term beautification.
Roadside vegetation plays an important role for highways, both during and after construction. Vegetation acts as a buffer and manages stormwater to prevent flooding and erosion.
The use of compost BMPs (compost blankets, filter socks and berms) can strengthen and benefit the soil through a variety of mechanisms.
Compost-amended soil not only reduces the need for synthetic fertilizers, but also elevates soil organic matter (SOM). The U.S. Composting Council recommends SOM content of 5 percent to maximize water retention. Studies have show there may be no runoff from a typical rainfall event (< 1 in.) when ideal SOM levels are maintained.
Vegetation and soil amendment have been shown to be among the most cost-effective methods of stormwater management per gallon retained, adding to the many benefits of compost use for highway construction and roadside vegetation, which include:
Accelerate establishment of vegetation cover.
- Stimulate microbial activity that increases the decomposition of organic matter, which increases nutrient availability, improves the soil structure and degrades pollutants.
Retain a larger volume of water, which aids in establishing vegetation growth.
Related articles on highway construction and roadside vegetation:
Riparian buffers and erosion — compost to the rescue
Riparian buffers are vulnerable to erosion, especially in areas where human activities like agriculture and development have stripped away protective vegetation.
Topsoil loss — a problem on land — and the resulting sedimentation — a problem in the water — can both be reduced through upstream strategies designed to protect streambanks and riparian areas.
Erosion in riparian zones
Historically, riparian was linked to discussions about rivers. But the term is now used ecologically to describe anything related to rivers, streams and water bodies. It can even include areas around farm ditches dug to drain fields. As these trenches frequently channel runoff to nearby streams, they can become the capillaries of the watershed.
Riparian zones, if protected and well-managed, can provide that all-important first line of defense against the onslaught of stormwater runoff loaded with pollutants and sediment.
Rills and sedimentation seen in adjacent fields result when rainfall energy dislodges soil particles that are carried away in runoff. But when compost is used to increase soil organic matter, the impact of rainfall is buffered.
However, the use of stable, mature compost products is essential. Unstable and low-quality products will not offer the same performance and may actually contribute to the problem.
But as soils approach the recommended value of 5 percent organic matter, runoff is reduced and percolation increased. With this volume reduction comes lowered sediment and pollutant loads delivered to receiving waters. In fact, studies show that for a typical rainfall event (1 inch or less), there may be no stormwater runoff.
Buffer zones immediately adjacent to rivers and streams, when vegetated, offer additional protections.