QDMR Hydromulch Trials on Road Batters
in the Wet Tropics
Hydromulching road cuttings is an effective
way of reducing erosion and providing soil coverage to bind the
soil surface and retain organic matter and moisture. Organic matter,
fertiliser and soil ameliorants are combined with water, glue and
seed and then mechanically sprayed onto the bare soil surface. .
Cook Highway
.
The results of previous hydromulch trials on the Gillies Highway
in 2004, indicated the importance of addressing soil deficiencies
and increasing native species in the seed mixes.
. BIOTROPICA AUSTRALIA coordinated the
application of hydromulch works on the Gillies, Cook and Kuranda
highways in the 2005 wet season, comparing different fertilizer
types and the soil ameliorants, lime and Minplus™. In addition,
trials were established to examine plantings of fishbone fern
(Nephrolesis cordifolia) into rock gabion structures on
the Kuranda Range in early 2005. .
Monitoring after
the 2005 wet season, indicated a good ground cover response,
however sites were still very young and susceptible to weed
invasion. Monitoring at the beginning of the 2006 wet season,
indicated native grass establishment was well underway.
Kuranda Range
.
By autumn 2006, there were no discernible responses of sites to
fertilizer and soil ameliorant treatment. Further monitoring after
the 2005/2006 wet season, soil analysis and biomass production will
aim to provide solid baseline data and reflect treatment differences.
Small hydromulch works on slippage sites on the Kuranda Range
in the 2005 wet season, provide an example of research culminating
in very successful hydromulch application. After 12 months, there
is a 100% soil cover with contributions from all species present
in the hydromulch mix. This cover result provides evidence that
initial rehabilitation of road cuttings can be highly successful.
Biotropica Australia’s research into hydromulching techniques
provides valuable information for clients wishing to rehabilitate
large disturbed areas.
