Soil conservation - Simple Ways to Save the Bay.

by Mark A. Crook

Soil erosion is one of the gravest threats facing the Chesapeake Bay. Excessive sediment loads in the Bay and its tributaries have come to be a major form of pollution, severely stressing the aquatic life that depends on clean water for survival. All land is a potential source of eroding soil, and therefore every one of us can help prevent erosion.

Erosion is the process by which beating rain and moving surface water dislodge and carry soil particles, organic matter, and plant nutrients. The texture of the soil and its potential for absorbing water, the steepness of the slope, and the adequacy of protective cover on the soil are all factors that influence the extent of erosion.

The primary cause of erosion is the action of water on soil with insufficient vegetative cover. Although this is a natural process, human activity that disturbs land often accelerates erosion.

Everyone recognizes a gully as evidence of erosion. Unfortunately, not all erosion is as easily recognized. Muddy water in your stream or drainage ditch or on your driveway indicates that erosion is occurring. It may be visible only for a short time following a rain, but the damage will continue unless something is done. The following are other, less obvious signs that erosion is occurring:

• Bare spots on the lawn or property;
• Tree roots showing above ground (although some species, such as maples, tend to grow this way naturally);
• Small stones or rocks becoming evident;
• Gullies beginning to show;
• Built up silt in certain areas;
• Soil splashed on windows and outside walls;
• Stream channels becoming wider and deeper; and
• Fallen trees in stream channels.

Where is all this erosion coming from? Erosion can occur any place where water flows over bare soil. A less obvious example is a site that is apparently vegetated, but where the grass is thin, where leaves have been raked away, where weeds with poor root systems grow, and where the flow of water prevents more permanent forms of vegetation from getting started.

Look at your own property and determine where erosion is occurring. Now you are ready to correct the problem by following these simple soil conservation steps:

1. To improve infiltration of rainwater, construct driveways and footpaths with gravel, crushed stone, brick or wood rather than asphalt or concrete.
2. Construct terraces on steep slopes using timbers and filter cloth to slow runoff and trap sediment.
3. Seed newly graded areas immediately after earthmoving is completed, andmulch heavily with hay until seedlings take hold.
4. Construct access roads and lanes along the contour of a slope rather than up and down the slope.
5. Install house gutters and downspouts that discharge onto the lawn, not onto the pavement.
6. Protect the soil at downspout outlets using splash blocks or drainage tile.
7. Plant erosion-resistant fescue (grass) on steep slopes and critically eroding areas such as ditches that carry runoff from property.
8. Use erosion control matting or straw mulch to protect soil from erosion until vegetation is established.
9. Plant ground covers in shaded areas where grass is difficult to establish. (See "Conservation Plants of the Northeast," a pamphletavailable through your local soil conservation service [SCS] office.)
10. Plant rows of trees or hedges to reduce wind speed and reduce the probability of wind erosion.
11. Maintain a healthy lawn by regular maintenance and reseed when necessary. Let grass grow a little longer to further slow runoff.
12. Leave mulch cover on flower and vegetable gardens during winter months or sow a cover crop to reduce erosion and enrich the soil. Likewise, mulch open soil around shrubs and hedges.
13. Plant gardens in the most level areas, or if you need to plant on a slope, plant along the contour of the slope.

Many thanks to Jeanie Lewis, a CBF BayWatcher and employee of the Soil Conservation Service, for her valuable contributions to this pamphlet.