11 Feb What information can you give me on erosion control for pastures?
B.G.VirginiaAnswer: I am pleased to provide you with information on basic erosion control measures for pastures.Erosion Control Measures (Moench and Fusaro, 2008)Reseeding; Seeding 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.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. Plant Species for Reseeding (ATTRA)Combine bunchgrass species with a diversity of forage species, including plants with prostrate growth habit to provide both good water infiltration and protection against erosion and soil compaction. In your region of the country, I suggest considering the following species:Cool Season GrassesThese species can be fall or spring planted with a Brillion seeder or drill. If broadcasted double the seeding rate. Decrease seeding rate if mixing with other grasses and legumes to a total seeding rate of about 15 pounds per acre.1. Orchardgrass 10 to 15 lb/ac2. Timothy 3 to 63. Kentucky bluegrass 10 to 15 Cool Season LegumesThese species can be fall planted or spring frost seeded in northern regions. Plant in a mix with cool season grasses at about 5 to 10 pounds per acre for alfalfa and red clover, 1 to 2 pounds per acre for white or ladino clover. 1. Red Clover2. White Clover3. AlfalfaWarm Season GrassYou might consider planting hairy crabgrass at about as a warm season grass alternative. Broadcast in early spring or plant with a wheat or ryegrass nurse crop, just be sure to mow off the wheat or ryegrass when it gets warmer to allow the crabgrass to emerge and take root. Referenced below is a paper from New Zealand on erosion control for pastures as well. Resources: Hicks, D.L. 1995. Agricultural Practices Which Control Erosion, in Soil Erosion on Farmland. Wellington, NZ: MAF Information Services.Moench, R. and J. Fusaro. 2008. Soil Erosion Control after Wildfire. Colorado State University Extension.