Downsizing for Hydraulic Seeding Success
Erosion control contractor Mark Myrowich is ready for just about any hydraulic seeding project that comes his way-spraying a slurry of such materials as seed, fertilizer, tackifier, mulch, and bonded fiber matrix. In addition to his larger truck-mounted hydraulic seeder with a working capacity of 1,700 gal., a steel tank, and mechanical paddle agitation, he has a 500-gal. trailer-mounted hydraulic seeder also with a steel tank and mechanical agitation. He purchased the smaller unit first, when he started his business of Mid Canada Hydroseeding in Winnipeg, MB.Myrowich began with residential projects. “I looked at the average yard size in my area and bought a machine to match it,” he recalls. “One tank of mulch will cover the typical yard.” He pulls the smaller unit with a three-quarter-ton pickup truck, usually no farther than about 5 mi. when the tank is full of slurry. Designed for a one-person operation, the machine comes standard with a hose for maximum flexibility in tight quarters. An optional discharge tower allows one person to seed and mulch from the unit as a driver tows it around the job site.“The 1,700-gallon hydraulic seeder is more efficient on bigger jobs,” Myrowich notes. “If the job is 50 miles away and requires more than two or three loads with the smaller machine, I’ll take the larger one. Otherwise I’ll use the 500-gallon unit. I’ll also use that machine on smaller jobs up to about 200 to 300 miles away because it’s cheaper to haul that unit with the pickup than to take the large truck-mounted seeder.”Myrowich is one of a growing number of hydraulic seeding contractors who finds that the convenience, maneuverability, and economy of small to midsize hydraulic seeding machines – say, those with tank capacities of no more than about 1,200 gal. – make more sense than bigger, higher-production machines whose size and weight are limited by site and access conditions.As hydraulic seeding machines continue to evolve, they’ve become increasingly more sophisticated than the original, introduced in the United States in 1953: a two-piece unit consisting of a truck-mounted tank, agitator, engine, and pump, trailed by a separate discharge tower on wheels.Today’s models include the nimble BlueBird HS-15, a hand-pulled polyethylene unit that rolls on 8-in. wheels and holds up to 15 lb. of seed, fertilizer, and mulch. With electrically operated agitator and blower, one person can use the machine to seed 5,000 ft.2 in less than two hours, the manufacturer reports.Turbo Technologies Inc. in Beaver Falls, PA, offers what it calls the world’s first modular hydraulic seeding system. It features three components – a 50-gal. tank, a 4-hp engine and pump, and a 50-ft.-long hose. “This system can be transported by passenger elevator, pack mule, dogsled, or loader bucket; by hand; or in the trunk of a car,” describes Ray Badger of Turbo Technologies. “You can use it to seed a penthouse apartment, an enclosed courtyard, even a mountain top.”More commonly, the small and midsize units seed and mulch residential lawns, school yards, sports fields, parks, and cemeteries; overseed golf course greens and tee boxes; and control erosion on utility rights of way, in forests, and in other areas where the big rigs can’t go as easily or at all.Some of the models can be lifted onto and off pickup trucks. In fact, a growing number of contractors are placing these units on single-axle trucks with gross vehicle weight ratings of 26,000 lb. or less to eliminate the more stringent driver license requirements and higher insurance rates of the big hydraulic seeding rigs. Other contractors are placing the smaller machines on bumper-hitch or gooseneck trailers pulled by a pickup, a utility vehicle, or a tractor. At least one 100-gal. model can be towed by an all-terrain vehicle, the manufacturer claims.
Equipment dealer Chuck Austin with Revex in Hygiene, CO, tells of one 5,000-ft.2 revegetation project at a power-line construction site high up in the Colorado Rockies. “It would have been a real pain to clear the slope of debris and install erosion control blankets to protect the disturbed soil until vegetation was established. So the contractor used a four-wheel-drive pickup to haul a 300-gallon hydraulic seeder to the site and apply seed and mulch.”A 600-gal. machine played a key role in seeding and mulching small areas disturbed as part of a 15-mi. stream restoration project in Colorado. “Trying to reach those sites with a big machine would have been too costly,” Austin relates. “In this case, the contractor towed the hydraulic seeder behind a tractor-loader-backhoe. Whenever he had to cross the stream, he picked up the machine with the backhoe and carried it across to the other side.”Size, however, can be deceiving. Some manufacturers offer units designed to use an auxiliary tank for refilling. One or even two extra tanks of water can pay off by minimizing reload time or travel time to an offsite water source. For example, when using a 300- to 400-gal. machine to apply slurry with a hose, two garden hoses will often fill an auxiliary tank with water while the crew is pumping slurry from the machine. When the machine is empty, water is pumped from the auxiliary tank into the machine tank, filling it in just a few minutes. With ample water pressure on-site, a 425-gal. machine and an auxiliary water tank can rival the production of a much more expensive single-tank unit with at least twice the capacity.Another approach is to use a separate water truck to shuttle water to the hydraulic seeding rig when no water is readily available on or near the site. Depending on distance to the water source, a considerable savings in time can more than offset the cost of the extra truck and driver. “When teamed with a water truck, an 1,100-gallon unit can apply as much material in a day as a machine three times its size,” states Bob Jones of Bowie Industries in Bowie, TX. “The key to this performance is loading and mixing quickly. As many as 30 tankloads can be applied in a workday when using tower operations and an auxiliary water tank.”The strongest appeal of the small to midsize hydraulic seeders is the economics. One manufacturer, for example, lists one of its two smallest, 50-gal. units at $1,295. That compares to the $9,995 price of one of two 1,000-gal. models and the $27,995 price tag on its largest outfit, a 2,000-gal. machine.“In the past, small and midsize hydraulic seeders have tended to outnumber the large machines,” says Austin. “Now, that has even increased because there’s a real market out there. More guys are getting into residential application. Also the machines are getting more technologically advanced so that they can do more. Some small machines can even apply bonded fiber matrix products.”“Sales of entry-level machines, those under about 400 gallons, have picked up dramatically,” adds Jones. “There was probably a demand for this type of machine 20 years ago, but no one was addressing it then. The market for intermediate-size machines is more steady, with small annual growth as manufacturers continue to improve them.”More job versatility is also helping to boost demand for smaller machines. “Many contractors would rather have a piece of equipment they can use for both smaller and larger jobs, rather than being restricted to large projects by the big machines,” says George Braun of Reinco Inc. in Plainfield, NJ. “Also, because start-up contractors don’t usually forecast sales as far out as the large contractors, they would rather have a small to moderate-size machine, which they can use for whatever work is available.”Erosion control, hydraulic seeding, and landscape contractors aren’t the only ones buying small to midsize hydraulic seeding equipment. Wally Butman of Finn Corporation in Fairfield, OH, sees many other types of buyers entering the market. “Due to the tremendous amount of work derived from the robust economy over the past few years, grading contractors, golf courses, and landfills are buying the machines to do the work rather than subcontracting it out.“Based on average costs around the United States, it takes about 20 to 25 acres of work to pay back the initial investment in a 900-gallon hydraulic seeder,” Butman continues. “So if you’re a contractor with a lot of ground to cover, it’s a no-brainer. Buying the machine could pay back in the first job.”Whatever your reasons for buying a small to midsize hydraulic seeder, there are various features to consider.Size and PerformanceTypical job size is probably the most important factor. Butman suggests selecting a machine with enough capacity to cover a typical job site with a minimal number of tankloads to reduce fill time and build efficiencies. That in turn depends on the amount of seed, fertilizer, fiber mulch, and soil amendments to be applied. A standard turf application would include 6-10 lb. of seed (depending on variety) per 1,000 ft.2, 400 lb./ac. of fertilizer or an equivalent water-soluble fertilizer, and 1,500-2,000 lb./ac. of fiber mulch using the tower gun or extension hoses. “Depending on the agitation and mixing capabilities of the machine, a contractor should be able to mix around 50 pounds of mulch per 100 gallons of water,” Butman points out.“It is preferred to apply mulch with as much water as needed to mix the materials but with as little water as possible to prevent disturbing the site while applying the materials,” notes Braun. “Quality mulch mixing ratios vary from 30 to 35 pounds to 40 to 50 pounds per 100 gallons of water. Therefore, the capabilities of the equipment also depend on the material being introduced into the machine. Poor-quality materials or improper operation will limit the capabilities of that equipment.”As Jones sees it, the limiting factor, at least on larger jobs, isn’t coverage per load but availability of water. “The farther you have to go to reload water, the larger the machine you need to be efficient,” he says. “If water is right there on-site, an 800-gallon or 1,100-gallon unit can knock out a lot of work over a day’s time.”Jim Lincoln of TurfMaker in Rowlett, TX, argues that the amount of mulch that can be loaded and pumped in a single tankload is far more important than tank size or horsepower when comparing machines. Tank size, he says, is just one factor when measuring a machine’s capabilities, because the size of area covered per tank of slurry depends on the way it is applied. “If your objective is to spray a lot of water, a big tank helps. But if your objective is to spray a lot of mulch to help ensure the best seeding success, then a bigger tank with poor mulch-handling capacity doesn’t necessarily get you there.“With a small-enough nozzle opening, 425 gallons of slurry could cover as much as 1 acre [43,560 square feet]. You could easily mix in the appropriate amount of seed in 425 gallons of slurry to cover that acre. However, you couldn’t mix enough mulch in 425 gallons of slurry with any machine to adequately protect 10,000 square feet, much less an acre. Only so much mulch can be mixed in a given amount of water and still be pumpable. But, by using a large nozzle opening and adding the required amount of seed and 180 pounds of premium wood mulch, 425 gallons of slurry will cover from 2,000 to 3,000 square feet with a relatively heavy mulch application and provide an excellent probability of achieving sod-quality results.“Thus,” Lincoln concludes, “the best measure of a hydraulic seeder’s performance is its ability to quickly mix and then pump thick slurries through as much as 300 feet of hose.”Type of AgitationManufacturers who use mechanical paddle agitation say this approach is best for blending the higher-performing wood-fiber mulches, including bonded fiber matrices, with seed, fertilizer, and water because it is more thorough and faster than jet agitation, which uses pressurized flows of water to do the mixing.Jet agitation machines, on the other hand, have few moving parts, reducing maintenance needs and costs.Type of TankSteel tanks are stronger, heavier, and more durable than polyethylene tanks and feature paddle agitation. To prevent rust and corrosion, the interiors are usually covered with epoxy. Poly tanks, most of which have jet agitation, are less expensive and won’t rust or corrode. Also, they have no seams, which could spring a leak, and they are easier to clean. Equipt Manufacturing of Chaska, MN, offers a unique hybrid: a paddle-agitated poly tank.Type of PumpTwo basic types of pumps are used to move slurry out of the tank and through the tower gun or hose. The centrifugal pump is much more popular than positive displacement pumps, which include the double rotary gear pump and the progressing cavity pump. The centrifugal pump provides more volume than pressure. Everything else being equal, this type of pump will shoot slurry farther than a double rotary gear pump. The centrifugal pump also has a much longer life.The double rotary gear pump and the progressing cavity pump produce more pressure than volume. As a result they will pump thicker material through longer hoses and up steeper slopes using less horsepower. Double rotary gear pumps, for example, are used in the oil business to pump oil-field mud and in food processing plants to move material such as mayonnaise. Unlike centrifugal pumps, double rotary gear pumps can also be used to plant live Bermuda grass stolons and sprigs of other plants that don’t produce viable seeds.Other ConsiderationsDepending on make and model, hydraulic seeding equipment may include such features and options as a stainless steel tank, dual and electric hose reels, a hose extension, a clear water hose flushing system, remote hose shutoff, and cam-lock, quick-connect hose fittings.