Hydromulching

Hydromulching is the application of mulches, glues, seeds, stabilizers and soil amendments to the surface of the soil for the primary objective of revegetation. This treatment is applicable on domestic lawns, sports and recreation fields, parks, steep embankments, quarries and mines. The combination of monitor and extension hoses in one unit, allows us the flexibility to carry out work over a range of landscapes efficiently.

Hydromulching Equipment

Aquaseeding has trucks with a tank capacity of either 8000l or 2000l. The larger tank increases the speed and efficiency of application on large sites, but the smaller tank allows for ease of access in restricted height/access areas. This means we can undertake any scale of work in a safe and efficient manner, while meeting project deadlines.

Site Preparation

Hydromulching should take place after the final slope shaping and topsoil placement has been completed and the prepared surface should be free of weeds and large stone.

Standard Application Rate

  • Cellulose mulch @ 1500kg/ha. This is the industry standard rate for cellulose mulch as it ensures uniform coverage and optimum seed germination due to soil moisture being maintained longer around the seed. A rate higher than this will result in the seed being suspended in the mulch and not making contact with the soil. When using rates above the 1500kg/ha a Bonded Fibre Matrix is recommended which is a combination of straw and paper.
  • Seed as per the supplier's recommendation. Typical seeding rates are 100-400kg/ha of exotic species and 5-20kg per ha native grasses.
  • The seed mix will vary according to the season, soil condition and location.
  • The longer the seeds are mixed in the slurry tank, the greater the potential for breakage and for this reason the seeds are added immediately before application.
  • Fertilisers dependent upon soil analysis with typical requirements of 5-10l per ha of a pre starter fertiliser. Adding a fertiliser can reduce the germination of certain native species due to the effects of fertiliser salt on seed imbibition. Therefore a humic acid is used to promote microbial soil activity when using native species @ 5l/ha
  • Dye is used as an indicator to the operator to ensure a uniform coverage
  • Tackifiers@ between 4-7 kg per ha depending upon the degree of slope. Tackifiers are sticking agents that bind soil particles together and protect the surface from wind and water erosion. When applied with hydraulic mulch, Tackifiers increase the effectiveness of the mulch as a soil cover by binding the hydraulic mulch fibres and the surface soil particles together. Tackifiers create water stable surfaces, which means they are capable of repeated wetting and drying and do not lose strength after a series of rain events.

Main Advantages of Hydromulching

  • Conventional Hydromulching is suitable for low rainfall erosive environments, such as NSW, Victoria, South Australia or where slopes are shallow or intensive erosion protection is not required.
  • Increased water retention. At rates of 1500kg/ha mulch thickness is over 0.25 inch with all the seeds covered. Hydromulch has a high water capacity maintaining two and a half times its dried weight in water
  • Creates a uniform coverage with seed at the correct depth of the seed/soil matrix
  • Hydromulching can be undertaken on steep or inaccessible slopes where conventional seeding equipment cannot operate.
  • Creates a protective barrier over the exposed soil reducing the soil loss as the soils are no longer exposed to rainfall and wind erosion
  • Holds seed within matrix preventing the seed from being washed, blown or eaten and therefore guaranteeing a uniform coverage after germination.
  • Improves the speed of germination especially in drier areas as the seed is in contact with moisture for longer periods than conventional seeding methods.
  • Soil ameliorates may be added including fertiliser, lime etc.