May-June 2000

Come Together: Revegetation Projects Require Concerted Efforts

Article Tools

Create a Link to this Article

By Karen Brooker

Comments

Planning is based on finding out everything possible about the site before a shovel, fork, backhoe, or excavator even touches the ground. Natural resource managers are discovering that with comprehensive site evaluations, the likelihood of a successful project is enhanced. As the population of the United States increases and more pressure is put on our lands, public and private shifts in the management of all our land is taking place. Resource managers are increasingly choosing solutions that are sustainable, solve the specific problems of the site, and are attractive to look at-all within the budget provided.

The components of a successful plan include several areas of assessment. First, a study of the unique issues of the site must be addressed: What's wrong and what's right with the site? What are the parameters of the project? For instance, roadsides must opt for low-growing plants, allowing for driver visibility and emergency access. What will the human usage be? Historical data collection is required, as it often lets the manager know why there is a problem in the first place and what solutions were tried previously. This can bring to light hidden bugaboos.

Soil evaluations are critical factors in the equation. There is more going on under the soil than on top of it. If the soil has been severely disturbed, graded, or completely removed-as in the case of mine sites-the project manager needs to know this. Watershed and hydrology assessment is important, as the greatest project can wash away in the first storm if these dynamics are not understood and planned for. Plant and animal inventories, sun and wind exposure, microclimates-these are all essential parts of a complete baseline study.

In assessing a site, ask for help; useful data might already have been compiled. The US Geological Survey has compiled topographic and geologic maps that are available to the general public. In California and in most other states, the local cooperative Extension Service can help with analyzing soil fertility, structure, and nutrient content. And don't forget a maintenance plan. Often the forgotten step in the equation, a maintenance plan will address weed control (it's what everyone sees when the installers have all left). Comprehensive collection of data will also help in getting the correct seed mix.

Photo:Roadside Maintenance
Bare roadsides require more maintenance and are susceptible to erosion control

Paul Albright, president of Albright Seeds in Camarillo, CA, stresses the importance of choosing the proper seed mix-not only the species of seeds, but also the ratio of seed used with other types of seeds. This is because certain species will dominate and outcompete others if used in the same proportions. Sometimes nurse crops are used, such as Zorro annual fescue (Vulpia myuros ssp.), which is daylight-sensitive, and seed is set when the days get longer. This provides cover on the slope while waiting for other erosion control species to germinate and become established. Choose appropriate plant species for the site. Use an experienced contractor and reputable seed suppliers. Pay attention.

Each site is unique, and assessment of all the components will determine the most appropriate solution for the site in question. When creating a plan, remember Barry Commoner's four universal laws of ecology:

  1. Everything is connected to everything else.
  2. Everything must go somewhere.
  3. Nature knows best.
  4. There is no such thing as a free lunch.


Roadsides of Yamhill County

Yamhill County is a farming community located in the lower Willamette Basin in northwest Oregon. It is characterized by the high precipitation from October through June that results in substantial runoff from roads and adjacent lands. Tim Stieber, district manager of the Yamhill Soil and Water Conservation District, points out, "Many roadside areas in Yamhill County do not perform all the needed roadside functions. Some areas are actively eroding or are devoid of vegetation, while others are overgrown with brush or noxious weeds."

Roadside areas are unique compared to some other erosion control project sites. Roadside areas must perform multiple functions: (1) provide a legal and visual right of way, (2) drain road surfaces, (3) prevent land runoff from interfering with road travel, (4) protect the roadbed from erosion, and (5) prevent establishment of noxious weeds if the areas are properly vegetated.

Since all roadside ditches eventually drain into surface waters, roadside areas can provide another important function: filtration for roadway and adjacent land runoff. This runoff may contain heavy metals, salts, and hydrocarbons from roads and sediment and nutrients from adjacent lands. "Erosion of the roadside ditch area can also contribute sediment to the runoff stream if not properly stabilized," notes Stieber.

Yamill County roadside before seeding
Yamill County roadside before seeding

The local maintenance policy in Yamhill County had been to chemically spray the shoulder of the road, continuing into the drainage ditch and up the other side-a distance ranging from 8 to 15 ft. This left the area free of vegetation and consequently available or weed infestation and usceptibility to erosion.

Advertisement

Sam and Nancy Sweeney, owners of Country Heritage Farms in Dayton, OR, thought there might be a better way to keep weeds such as pigweed, large crabgrass, and Canadian thistles out of their fields. Sam approached the state, and together they came up with a solution to weeds along the roads. The joint venture was initiated by Sam, and a committee was formed consisting of Yamhill Basin Council, Yamhill Soil and Water Conservation District, Polk and Yamhill Public Works, Oregon State University, and the Oregon Department of Transportation.

Using a zonal approach to seeding, two grass species were chosen: roughstalk bluegrass (Poa trivialis), which tolerates very wet conditions, and creeping red fescue (Festuca ruba) on the road shoulder, a low-growing grass. Creeping red fescue retains driver visibility, provides a thick thatch for erosion control and sediment entrapment, does not aggressively grow into adjacent fields, and is easy to maintain, requiring only one mowing per year. Next Page >

What Do You Think?

Post a Comment

Be the first to tell us what you think!

Post a Comment

Not a subscriber? Sign Up
 
 
*  
 




 

Get Erosion Control E-mail Updates!

Get weekly news and updates through our Erosion Control e-mail newsletter!