Tacking Hay & Straw
Hay or straw (long fiber mulches) are applied over newly seeded areas to provide temporary erosion control, moisture retention and a protective "blanket" that protects the seedbed, thereby creating a 'micro-climate' promoting seed germination and seedling growth. Application rates range from a minimum of 2000 lbs. per acre to as much as 4 tons per acre. Application of these mulches is performed after the initial seeding. This seeding and mulching process is commonly referred to as the 'Two Step Method' (TSM). To protect the seedbed and materials placed, some method of anchoring is often recommended. As the long strand hay or straw mulches were prone to blowing off the site, 'tacking' or sticking the mulch is required to prevent movement of the placed materials. Tacking is most often the most economical means.
Using Fiber Mulch
Hydraulic fiber mulch is utilized as a hay or straw alternative that readily mixes in a Hydrograsser along with seed, fertilizer, lime, and tackifier, allowing all amendments to be applied simultaneously. This application is commonly referred to as the "One Step Method" (OSM). Fiber Mulch is made primarily from processed wood fibers or recycled paper (or combinations of the two) and is normally packaged in bags or bales weighing 30 to 60 pounds. Most contain a green dye which helps traceability and improves the appearance of the sprayed area. It's use eliminates the need for a separate mulch application. Popularity of hydraulic fiber mulches increased over the years as a clean alternative to hay or straw mulches. This is the most common hydrograssing process today and is often what is considered when hydraulic seeding is called for.
Large scale seeding operations (such as highway reclamation) usually prefer the 'Two Step Method' (TSM) as labor, time and water requirements are significantly reduced, compared with the 'One Step Method'(OSM). For example, with fiber mulch, 3000-3500 gallons of water are required to seed, fertilize and mulch one acre of prepared seedbed. With even the largest machine and the most experienced crew, this is a time and labor consuming practice. Without the fiber mulch, a single acre can be seeded and fertilized with 500-750 gallons of water. To then apply a hay or straw mulch, would require as little as 10 minutes, up to one hour per acre with a Power Mulcher, depending on equipment selection.
Application of hay or straw mulch utilizing a Power Mulcher greatly reduces labor costs and results in a more uniform and effective cover. There is much evidence, also, that these mulches perform better than fiber mulch alone. Compared to other hay or straw application methods, as much as 30 % less material is required when a Power Mulcher is used. For more information on these productivity and cost factors, download a copy of the 'Cost Analysis'.
A 'Tackifier' is a bonding or adhesive agent that is used for hydraulic seeding and hay or straw mulch tacking. As discussed earlier, wind will often blow hay and straw away, while the impact of rain will often cause breakdown of the surface topsoil allowing fines to seal and promote ponding, encouraging the possibility of erosion. Usually tacking was done by spraying an emulsified asphalt emulsion directly with or over the mulch. Because of the environmental and logistical problems associated with petroleum based tackifiers, fiber mulch used either as a tackifier over the long strand mulch or applied using the One Step Method became more common. Fiber mulch alone or as a tackifier is acceptable as long as the mulch retained moisture. If the mulch dried out the tacking becomes ineffective.
In search of a solution, the Reinco research and development team introduced the first biodegradable powdered tackifier in 1968. This multi purpose product called 'Terra Tack™' (which became the industry benchmark for performance), could be used to effectively keep hay and straw mulch in place. Reinco Mulch Binder (RMBplus) was an improved formulation of the earlier products. Through 2007, Reinco offered TRACER™ TACKIFIER which was an improved formulation, applied at 6 lbs per acre verses the earlier 100 lb rate. Today, Reinco offers Terra Tack™ SC packaged in convienent 6 lb jugs. Readily mixed with water in a hydrograsser or similiar mixing/spraying apparatus, the tackifier slurry is then oversprayed onto the long fiber mulch and when cured becomes a permeable linked mat. This method of seeding is now aptly referred to as the 'Three Step Method' (3SM).
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