“If you go to the basic biology of it, there are two basic principles,” says Mark Fiely, horticulturist at Ernst Conservation Seeds. “The new roots lock the soil in place and the leaves reduce the velocity of the rain.”
Fiely always recommends planting diverse species. While some may have taproots or corms, most have a fibrous root network to stabilize the soil. He also selects species to interrupt the rain above and at ground level. These include grasses and flowering plants, some of which form rosettes.
When feasible, trimming the vegetation during the establishment year is beneficial. “Whenever the vegetation gets knee high, trim it down to eight inches. This prevents faster-growing vegetation from smothering the rest. It also reduces pollen production weed seed set from plants like ragweed.”
It is also important to spot-spray problem weeds. Without spot spraying, problem species such as Canadian Thistle, mile-a-minute, or kudzu can become established and take over. Ideally, spot spraying should be done in subsequent years as well.
Planting diverse species has benefits beyond erosion control, he notes. Flowers provide beauty and fragrance for the property owner. They and other vegetation provide food for pollinators and grassland birds as well as habitat for wildlife. Diversity also provides insurance in case some of the species don’t do well.
“For the long haul for the environment, it’s good to be good stewards of the land,” he says, “and when we have these options, we can be creative and innovative.”
A stroke of good luck led to the creation of a beautiful pond at Cedarleaf Farm, a Stewardship Forest certified by the South Carolina Forestry Association: One day a forester thinning the trees exposed a boggy area fed by a spring.
The pond, built and planted with native seed in March 2011, looks like it’s always been part of the landscape.
“All my life I’ve dreamed of having a pond,” says Joanna Angle, a South Carolina Master Tree Farmer who has won two honors recently. She was named the 2012 South Carolina Tree Farmer of the Year and the local US Department of Agriculture’s 2013 Soil and Water District Conservationist of the Year.
Angle began developing the tree farm, a former cotton plantation, in 2001. She sells enough timber to reach her goals of creating a legacy forest of mixed hardwoods and pine, a habitat for wildlife, and a destination for agritourism, which includes miles of trails and a teaching forest.
Thanks to Ernst Conservation Seeds in Meadville, PA, her 65-acre farm in Lewis Turnout, Chester County, now includes a vernal pond with a dam planted in native grasses and wildflowers.
“It’s beautiful,” she says. “It has ducks, dragonflies, hummingbirds, and bats. Last summer we had pileated woodpeckers nesting beside the pond.”
The pond, about a tenth of an acre, was excavated and built of clay. The dam is also of clay. The back side of the dam is approximately one-fifth of an acre, close to 100 feet across and tapered off around the sides. Because of the shape of the land, it is some 15 feet at its highest point, with a slope at about a 30-degree angle. The rim is about 12 feet wide, a perfect site for relaxing at the end of the day.
The pond was built in March 2011, leaving the back of the dam exposed to wind and rain during a season when the weather is very unpredictable in South Carolina, she says.
“You can be in shirtsleeves one day, and the next day you can be watching a whiteout blizzard. But the pond had been built, and the rainy season was starting. We had to get the seed into the ground in very fast.”
Angle did the work with her two part-time employees.
“My learning curve was steep on the dam,” she says, adding that Fiely mentored her through the process. “Once it started happening, the seeding took a matter of days.”
Crews brought in two dump truck loads of aged pine mulch to amend the soil and worked it in with rakes and a small walk-behind tiller, which was difficult because the slope was so steep.
Fiely recommended Ernst’s Piedmont SC Steep Slope Mix, which consists of 16 native grasses and wildflowers that blend in beautifully with the wildflowers and native grasses that already thrive on her property. The species in the mix include Indiangrass, Virginia wild rye, little bluestem, purple top, partridge pea, white wild indigo, lance leaved coreopsis, purple lovegrass, spotted bee balm, black eyed susan, winter bentgrass, Appalachian beard tongue, wild quinine, rattlesnake master, grassleaf blazing star, and showy goldenrod. Fiely also chose the fast-growing brown top millet as the cover crop.
He always uses a combination of species to achieve the dual goals of stabilizing the soil with fibrous root systems and reducing the velocity of rain with leaves or rosettes, he says.
Typically, the species grow in three stages. The cover crop is the first to grow leaves large enough to protect the soil from rain and roots large enough to stabilize the soil. The second is the “nanny” crop, in this case, wild rye. These crops grow fairly quickly and continue to protect the soil until such slower-growing biennials and perennials as black-eyed susan take over.
“It takes about four years to raise a meadow,” he says.
Fiely also recommended that Angle and her two employees mix the seeds with clay-based cat litter before broadcasting them.
“We have crops whose seed counts range from 1.5 million to 4 million per pound,” he says. “A bulking agent allowed them to more uniformly apply the seed. Cat litter holds the seed, so when you throw, it carries the seed better.”
They broadcast the seed at a rate of 20 pounds per acre, which for her fifth of an acre was 4 pounds, and tamped down the soil by stepping on it and with the back of a rake.
“After all that, we put down a heavy hemp landscaping blanket, which composts as it goes,” Angle says. “We covered the blanket with wheat straw for aesthetics and to give the seeds a little more protection from the rain or a late frost.”
There was no source of sprayable water for the seeds, but fortunately there was enough water from rain that fell. The biggest challenge once the project was completed was “rogue raccoons digging up the seeds,” she says.
“I am thrilled with it, absolutely thrilled. There’s no erosion, none. It looks like it’s always been there.”
Union Pacific Railway Switching Yard
On a barren stretch of desert in southern New Mexico, miles from the nearest creek, the Union Pacific Railway (UPRR) is expanding its switching yard.
Crews had to coordinate with an active railway during the project. Vehicles had to cross the tracks some 50 times a day.
“There’s already a lot of existing railway because of the history,” says Sam Stribling, chief executive officer of Eight 14 Solutions, which did the seeding for the erosion control portion of the project. “The switching yard isn’t only a hub for the transportation of goods; it’s also a hub for Amtrak.”
Eight 14 Solutions specializes in seeding. The company just hit its three-year anniversary mark and has already won an award for its work. At the New Mexico Mining Association annual conference in 2012, the Department of the Interior’s Energy, Minerals and Natural Resources Department awarded the company its Excellence in Reclamation Award for its part in the reclamation of abandoned coalmine lands.
The UPRR seeding project, which took place in December 2012, stabilized both sides of the elevated tracks along the right of way, approximately 4 miles long and 1 mile wide. The site includes nine ponds for excess dirt and eight stormwater detention ponds with steep, windswept slopes, as well as a number of roads, some of them elevated.
The ponds are substantial in size. They range from 10 acres to some 25 to 30 acres, with 2.5:1 slopes anywhere from 120 to 150 feet long.
“The soils are a real fine sugar sand,” Stribling says. And it got windy. Some gusts reached 65 to 70 miles per hour, reducing the visibility to 20 feet or so. Crews had to shut down the job for several days because of the wind.
The seed, which was specified by New Mexico Department of Transportation, was supplied by Granite Seed and Erosion Control, which has offices in both Utah and Colorado.
“Granite Seed is great,” Stribling says. “The owner wanted modifications as the work progressed. The project size increased, and we had to make adjustments for additional acreage that was going to receive final stabilization, which meant ordering additional materials in a just-in-time manner. Especially with a project of this magnitude, it takes some time to get the seed prepared, but Granite supplied an additional 100 acres of seed material in a matter of days.”
Another challenge was that the turnaround time was short. “Because the switching yard was an active construction site, it was important to get the areas under this permit completed with final stabilization,” he says. “The date of completion, so that the second phase could begin on time, meant that we had to increase the number of our crews. We were running the equivalent of three separate crews at once to meet the daily production quantities.”
And there were delays. The modifications required extended quantities of materials from all the subcontractors. On top of that, and the delays because of excessive wind, the project took place during the rainy season, and work had to shut down for several days because of the rain.
Although the job took place in a barren part of the desert, the site itself was filled with activity. A construction crew working on the railway was using heavy equipment, and Eight 14 Solutions had to coordinate with them.
Workers also had to contend with trains barreling along the tracks at all times of day. “There were numerous railway crossings constantly in use that we had to carefully coordinate movement of material and equipment across,” Stribling says. “A dozer moving across the tracks doesn’t move especially quick, and we had to cross generally 50 to 75 times a day.” The crews would usually get a warning that a train was coming, but they also cleared it with the rail yard just to be safe.
Eight 14 Solutions used 289 pounds of seed: blue grama, Indian ricegrass, galleta, western wheatgrass, sideoats grama, four-wing saltbush, Arizona cottontop, alkali sacaton, sand dropseed, annual ryegrass, barley, and Quickguard sterile triticale.
Quickguard is a fast germinating cover crop that was chosen to help with temporary soil stabilization and to control some of the blowing sand, explains Kevin Langham, Eight 14 Solutions’ chief operations officer. Although a typical New Mexico drill seed rate would be somewhere between 18 to 25 pure live seed (PLS) pounds per acre, this mix was increased because the company knew it would be doing both drill seeding and hydroseeding, at the same rate.
Most of the site received an application of 18-24-12 fertilizer, except for the stockpile locations.
Crews used a series of drill seeders to seed a total of 157 acres. All the company’s seeders have been custom fabricated to meet the site conditions they typically see and to ensure they are getting a high quality product.
“We typically run crews in tandem,” Stribling says. The lead tractors disked the soil, allowing the drill seeders behind it to break into the ground and drill the seed. Then the Finn B-300 straw blowers shredded the mulch and blew it over the seeded areas. This processor has an opening wide enough to hold a 4x4x8 bale of straw and a chain system to hold and feed additional bales. To get enough traction to climb the slopes, crews pulled the processor with a bulldozer. They hydroseeded 132 acres with several of their Finn T-330s, which are on specialized truck chassis, to perform the work within the short timeline. The area included the portions of the ponds that were too steep to drill seed. Hydroseeding crews also did the areas close the rail line because the almost constant wind blew the straw from the processor, reducing their visibility. There was no requirement for irrigating.
Because the seed is a native seed blend and the site is a desert, it’s difficult to tell how well the vegetation will come in, he says. Most often a native seeding operation like this provides a significant addition in vegetative cover density and plant diversity.
Even with the delays, Eight 14 Solutions seeded 290 acres in just under two weeks, a total of 29 acres a day. “That’s a considerable amount of seeding,” Stribling says. “Our crews were great. I’ve had the pleasure of knowing some of these guys since the late ’90s. Projects of this magnitude, with tight timelines and difficult site conditions, give them the opportunity to flex their muscles and show their level of production and quality.”
Another reason they were able to work so efficiently was due to the careful planning and coordination of the prime contractor, Ragnar Benson, which handed over the finished sections as they were completed and was willing to accommodate the long workdays of the quality-control and oversight team, Wilson & Co.
“Without a doubt, Eight 14 Solutions was able to complete the quantities needed on a daily basis due in large to the great teamwork of all of the teams,” Stribling says. “Everyone is extremely pleased with the results.”
Often native species are planted without amendments. When the soil has lost its nutrients, its structure, or its ability to retain moisture, however, plants grow more successfully when amendments are added, according to the National Parks Service. Soil remediation may involve incorporating large amounts of organic material such as lime, or a temporary cover crop such as rye or wheat grass.
Aerial view of Northstar Resort
In the case of Northstar Resort in Truckee, CA, a popular skiing, snowboarding, and mountain biking destination, a fertilizer such as Biosol, which also builds humus, is very useful for enhancing revegetation on slopes with little or no topsoil.
Northstar, located at the headwaters of tributaries to the Truckee River in the Sierra Nevada mountains, opened more than 40 years ago, in 1972. In 2011, it constructed a 56-acre skier improvement project that included a new chairlift, three new ski trails, and snowmaking lines.
Northstar staff and Kelley Erosion Control Inc. revegetated the exposed areas, says Kym Kelley, owner of the company. Kelley serves both Nevada and California and revegetates soils disturbed after construction, including highways, airports, and mines. The company has won numerous awards from the Tahoe Regional Planning Association, and one from the Nevada Recreation and Park Society.
Northstar employs an erosion control and revegetation crew each summer and was an active participant in the California Alpine Resort Environmental Cooperative and the development of the Sediment Source Control Handbook, which provides guidelines for erosion control and revegetation at California ski resorts.
The project was designed and constructed with the guidance of the Northstar Habitat Management Plan, which provides the framework for the management and protection of natural resources at the resort while providing for resort operations and construction.
Northstar specified native seed from Comstock Seed in Gardnerville, NV, and Biosol, a soil amendment from Bowman Construction in Denver, CO, because of the product’s successful track record in the area.
“They are really happy with Biosol, and Bowman is good to work with,” Kelley says.
Biosol is the byproduct of the manufacture of penicillin, according to Bowman Construction. Raw materials that produce penicillin are fermented, and the penicillin is removed. The remainder is a fungal mycelium. Biosol contains some 96% dry mycelium and 4% water.
A natural organic fertilizer that releases nutrients continuously throughout the growing cycle, Biosol contains nitrogen, phosphoric acid, and potash. Because it builds humus and feeds soil microbes and mycorrhizae, it is especially useful in harsh conditions with little or no topsoil.
The growing season on the mountain is short because of the high elevation. Crews used a wide variety of native seeds, including mountain brome, blue wildrye, squirreltail, bitterbrush, a native species of ribes, and a Sierra wildflower mix.
Due to the high elevations and the heavy snowfall the previous winter, the project start was delayed until the second week of July 2011. All revegetation was completed by mid-October.
The trees were removed with equipment that minimized compaction and soil disturbance.
Merchantable material was hauled offsite. Non-merchantable material was chipped in a tub grinder at various sites or masticated within the project to create stockpiles of woodchips for use on the project.
There were a number of challenges, but the time constraint was the biggest, Kelley says. “The work was done in the fall, and we were following behind the clearing and snowmaking operations. There was a lot to get done before the snow flew. It was pretty intense.”
Northstar had a 12-person crew and contracted with Kelley, which had a six-person crew, to help complete the job. The crews worked section by section as the clearing, grading, and snowmaking operations were completed, finishing the project in three months before the first snowfall.
The site itself was daunting. The altitude at the base of the mountain is 6,330 feet, and the elevations for this project ranged from 6,740 to 8,300 feet. The slopes ranged from 25% to 50%. Some were rocky and others were covered with a slippery layer of litter left over from the tree removal. “The majority had to be hand-worked,” Kelley says. “It was very time consuming.”
Access was another challenge. The ski run alone was more than 2,000 feet long and up to 300 feet wide, Kelley says. “Access roads cut across the ski runs. They’re spaced pretty far apart, at least 700 feet to maybe 1,000 feet apart, depending on the slope, and you have to access from that point.”
Some of the slopes were almost dangerous to walk on because of the debris. On these slopes, crews dragged a 1,000-foot hose downhill and sprayed the seed, at 100 pounds per acre, together with Biosol.
On the other slopes, they used a Marouka, a tracked dump truck, to drop piles of wood chips onto the newly cleared ground. They spread them about 1 inch thick, often by hand, then tilled them in 12 inches deep where possible, along with Biosol, using an excavator bucket. This process incorporated organic material into the soil as well as loosened the soil and created surface roughness to promote infiltration of water during a runoff event, thereby preventing soil erosion.
Crews spread the seed by hand at 75 pounds per acre, from an ATV when it was possible. The final step was to spread a layer of wood chips by pitchfork on top of the seed.
More than 7,000 cubic yards of wood chips were used for the project; some were from the trees that were removed and some from an adjacent fuels management project at Northstar, which were hauled to the project site. “The materials were there,” Kelley says. “Instead of buying something, they used the wood chips from the pine trees that had been removed for the ski run.”
Northstar has been recognized for its environmental efforts; it has received California’s Waste Reduction Awards Program (WRAP) award for the past 13 years. Through recycling and reuse programs, as well as using technology instead of paper, the resort has diverted approximately 255 tons of material from the landfill.“We had good success with that project,” Kelley says. “Everybody’s happy with the results.”