Jan. 14, 2013 04:05

Hydroseeding or Mulching?

Dealing with natural disasters like fires, floods, hurricanes and tornadoes is an inevitable part of life on earth. When we aren’t battling these often unpredictable occurrences, we’ve got everyday, “normal weather” phenomena, like wind, rain and snow to deal with.

The part that people tend to forget is that all of these events have a profound impact on one of the most important elements of our planet: soil. So whether our concerns are based on erosion, stormwater runoff control, or clearing land for new developments, protecting the soil is a major priority in our industry.

Take fires, as an example. Sure, they’re devastating to families and individuals, but what about the effect that fires have on the environment? When fires sweep through hillsides, they leave behind large, barren areas of land. As the soil becomes oversaturated with rain, these grounds become problematic. With no plant material to hold the soil in place, it slides down the slopes and oozes onto highways, waterways, and homes.

When Mother Nature goes on the attack, the impact it has on the environment is something we cannot control. The damage it brings can be overwhelming. For example, that massive fire in Colorado last year left hundreds of thousands of acres denuded. Fortunately, most of that acreage was in the forests. However, where it infringed on the urban and suburban areas, properties and homes were lost.

Unfortunately, when Hurricane Sandy hit, those living on the East Coast—especially along the beach areas from Florida to Maine—were not so lucky. Along with hundreds of homes and properties, hundreds of miles of beaches were left eroded.

Now it’s up to us, the professionals, to try to put together what was damaged. Although this will be a massive job, there are methods and equipment that allow us to help restore some of the earth’s elements, like the soil.

One such method is hydroseeding. Hydroseeding is the application of water, wood fiber mulch, seed and fertilizer, to prevent soil erosion and provide an environment that is conducive to plant growth.

“The machine does most of the work, ”says Ron Dietz, owner of Dietz Hydroseeding in Sylmar, California. “It’s simple, quick, and very effective. First, you add your materials to the tank and mix it with water. Agitation blades mix the materials together to form a slurry, which is pumped out and sprayed onto the landscape. With a big enough tank, you can do an acre an hour. It usually takes two or three of my guys to operate the hydroseeder. The benefits, as far as time and energy goes, can’t be matched.”

Also known as hydraulic mulch seeders, they are typically used for applications on large surfaces, slopes, and other hard-to-reach areas. They’re often used to apply plant material on commercial projects such as parks, schools, golf courses, and along the sides of highways and interstates.

These machines come in a variety of sizes, ranging from 100- to 3,000-gallon tanks, and beyond. They can be mounted on a truck or pulled by a trailer; smaller units can even be placed in the bed of a pickup truck.

“With hydroseeding, you have three different types of applications,” says Dietz. “You can plant seed, apply amendments like fertilizer, or install erosion control measures with binding agents. You can choose to do one of these applications, two of them, or even all three in one step.”

When mulch is added to the slurry and applied with the seed, erosion issues are almost history.

Hydroseeders use a pump to propel the slurry through a hose (often 100 to 200 feet in length), and across the landscape.

As the slurry dries and the seed germinates, the wood or paper mulch keeps the seed covered, and tackifiers bind the material to the soil. If a Bonded Fiber Matrix (BFM) is added to the mix, when it rains the water simply runs down the slope.

Hydroseeding is less costly than installing sod, and depending on the quality and amount of seed you use, it can produce a terrific stand of turf. The process is fast, very cost-effective, and invaluable when it comes to keeping erosion at bay—especially following a natural disaster.

Another viable method of controlling erosion is mulch blowing.

The sentiments here are very similar to those regarding hydroseeding: blowing mulch requires less time and manpower to rapidly cover large areas of land.

“Mulch blowing is a totally different animal. When you’re hydroseeding, it’s only for seeding and controlling erosion,” says Victor Acevedo, regional sales manager at Peterson Pacific Industries in Eugene Oregon. “A mulch blower is able to move several different types of materials—from a compost seed mix all the way up to wood products.”

Just like hydroseeders, mulch blowers are available in a variety of shapes and sizes. Tractor/trailer configurations have the capacity to carry large amounts of material, while smaller units can be towed behind a pickup truck.

Mulch is piled into the top or rear of the machine and fed through a rotary airlock conveyor. The material is then propelled through a specially engineered blower system and onto the landscape through blower hoses.

With hoses extending hundreds of feet, crews can efficiently blow material onto inaccessible spaces up to 200 feet from the operator. Because the average hose weighs only one pound per foot, the equipment offers exceptional maneuverability and portability. This makes mulch blowing ideal for hard-to-reach areas like hillsides.

The operation is quick, too. Imagine the time it would take, using a wheelbarrow, to lay down mulch on hundreds of yards of land…with a blower truck, it can be done in one load.

“You can get in and get out quickly, and it’s very versatile,” says Jeff Johnson, vice president of Power Mulch Systems Inc., in Smithfield, North Carolina. “That’s one of the benefits of what a mulch blower can really do. As long as the material can fit through the hose, you can blow it out.”

Although you can use a variety of materials, there are certain kinds of mulch that are typically run through the blowers. They include wood fiber, paper, straw and reclaimed cotton. There are also combinations of these options, some of which include polyacrylamides (PAMs) that keep the pores of the soil open, and allow water to seep inside.

If you need to do seeding, there is an attachment available. Some manufacturers offer a computerized seed injector that is attached to the machine. As the material is sent through the blower, a computer measures the amount of compost being processed, and injects the seed directly into the airstream at a constant rate. It’s an easy option for blending seed into soil enhancements and compost.

When the mulch is blown over the soil, it covers the ground like an ‘environmental carpet.’ First, the mulch locks in moisture and shuts out environmental hazards. That protective cover allows the soil to retain its moisture by reducing the potential for evaporation.

This minimizes the need for watering. Keeping the seed moist encourages germination. It also reduces weed growth, and provides a layer of nutrients to fight off decay. The mulch serves as an insulator for the root structure of your plants, keeping them warmer in the winter and cooler in the summer.

As an environmental carpet, it also prevents soil-borne diseases from splashing onto plants or infiltrating stormwater. Creating berms of mulch is another effective method of reducing hillside runoff.

Lastly, mulch is aesthetically pleasing. It improves the appearance of front or back yards and roadsides, by giving it a complete, attractive, and finished appeal that enhances the beauty, uniformity, color and texture of a landscape.

“If you’re using wood chips, mulches compliment and accent an area based on the color of the landscape. The wood chips are dyed, and the color you use depends on whether you want light mulch, dark mulch, amber red mulch, black mulch etc.,” says Johnson.

These are the basic uses and differences between hydroseeding and mulch blowing. An investment in either one of these pieces of equipment requires some careful thought and consideration. However, if you can justify the cost, both machines could wind up saving your business a significant amount of time, and in turn, money.

You may want to consider factors like cost versus benefit. Some mulch blowing machines can cost between $100,000 and $500,000. This is a pretty hefty investment to make. You want to make sure you can keep that piece of equipment working to make it worth your while.

“Very few contractors have the amount of work to warrant this type of investment,” says Sohelia Sturm of Landscape Support Services, Inc., in Santa Clarita, California. “That’s the reason why we’re here. Because we have this equipment, we can offer to be the subcontractor; the contractor does not have to turn the job away. What’s even more exciting is that if he goes to our website, he can fill in the details of what kind of material he wants for the job—the size of the property, and the amount of material—and he can get an instant quote. ” In comparison, hydroseeders are less expensive. For example, if you’re looking to buy a hydroseeder with a small, 100- to 200-gallon tank, you’ll find them for about $1,000 to $2,000. But if you’re in the market for a big one, with maybe a 3,000-gallon tank, you’ll be looking at prices somewhere around $75,000 to $90,000. However, this also includes the vehicle.

Again, it all depends on the workload and the kind of jobs that your company takes on.

Before you toss your file of research into the recycle bin, know that there are huge benefits awaiting you. If all the pieces come together, you’ll be able to accomplish more with either one of these pieces of equipment, in less time, than ever before. We all know what that means in the long run: saving money—which means making money.

Also in Soil Erosion News


In many ways, we are fortunate that, in our chosen profession, we are able to help people when certain disasters occur: the tornadoes in Missouri, Oklahoma, Louisiana and Georgia, the flooding in Louisiana, the snows in the northeastern part of the country, the rain in California, and the snow in Colorado....

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