03 Aug What information can you give me on erosion control, including reseeding?
C.J.West VirginiaAnswer: I am pleased to provide you with information on reseeding and erosion control.Reseeding Tips for Large Areas1. Control existing vegetation.2. Plant cool season perennial grass such as a tall fescue and perennial ryegrass combination. 3. Seed to soil contact important so best to drill the seed in 5 to 7 inch row spacings. 4. Plant these grasses at about .5 to .75 pounds of seed per 1000 square feet. 5. After planting the perennial grass mix, plant oats either by broadcasting them over the area or drilling perpendicular to the perennial grass rows, at 1 to 1.5 pounds per 1000 square feet. 6. The oats will emerge first and provide weed control as well as soil stabilization as the perennial grasses emerge. In order to keep the oats from competing with the emerging perennial grass seedlings, mow the oats to a height of 3 to 5 inches. 7. The oats will develop seed heads as the season progresses, and can be terminated by mowing when the seeds begin to turn brown. By this time the perennial grasses should be well established, if you have done a good job of controlling oat growth so to prevent competition.Reseeding Tips for Hand Planting Small Areas1. Roughen the soil surface to provide a better seedbed by breaking through the hydrophobic layer. A steel rake works well for this, or, depending on the slope, a small tractor drawn harrow could be used.2. Broadcast the seed (a “Cyclone” seeder works well). Seeding rate depends upon the variety of seed sown. A good estimate is 10 to 20 pounds per acre of grass seed with another 10 to 15 pounds per acre of the nurse crop. Spread straw over seeded areas to prevent erosion. 3. Rake or harrow in 1/4 inch to 3/4 inch deep.4. If the area is small enough, roll or tamp the seed down to ensure good soil/seed contact.5. Spread weed-free hay straw. If the area is small, crimp the hay in with a shovel. (This will help keep both soil and seed in place during wind and rain.)6. Control weeds as needed by cutting off the flower before it can seed.You may need to install some drainage structures to prevent water from entering the area and creating a bog. Here is a list of practices you might consider:Contour log terracesLog terraces provide a barrier to runoff from heavy rainstorms. Dead trees are felled, limbed, and placed on the contour perpendicular to the direction of the slope. Logs are placed in an alternating fashion so the runoff no longer has a straight downslope path to follow. The water is forced to meander back and forth between logs, reducing the velocity of the runoff, and giving water time to percolate into the soil. Logs should be 6 to 8 inches in diameter (smaller logs can be used) and 10 to 30 feet long. The logs should be bedded into the soil for the entire log length and backfilled with soil so water cannot run underneath; backfill should be tamped down. Secure the logs from rolling by driving stakes on the downhill side. It is best to begin work at the top of the slope and work down. (It is easier to see how the water might flow by looking down on an area to better visualize the alternating spacing of the logs)Straw WattlesStraw wattles are long tubes of plastic netting packed with excelsior, straw, or other material. Wattles are used in a similar fashion to log terraces. The wattle is flexible enough to bend to the contour of the slope. Wattles must be purchased from an erosion control material supplier. Silt FencesSilt fences are made of woven wire and a fabric filter cloth. The cloth traps sediment from runoff. These should be used in areas where runoff is more dispersed over a broad flat area. Silt fences are not suitable for concentrated flows occurring in small rills or gullies. Silt fences are made from materials available at hardware stores, lumberyards, and nurseries.Straw Bale Check DamStraw bales placed in small drainages act as a dam – collecting sediments from upslope and slowing the velocity of water traveling down slope. Bales are carefully placed in rows with overlapping joints, much as one might build a brick wall. Some excavation is necessary to ensure bales butt up tightly against one another forming a good seal. Two rows (or walls) of bales are necessary and should be imbedded below the ground line at least six inches. Resources:Hicks, D.L. 1995. Agricultural Practices Which Control Erosion, in Soil Erosion on Farmland. Wellington, NZ: MAF Information Services.