The Forestry and Land Rehabilitation
market for recycled organics is a rapidly growing sector of Bio-Recycles
land application programme. Tremendous increases in tree growth and
trunk diameter have been noted following an application of biosolids.
pastures have been established on rocky, denuded areas such as opencut
mines, closed landfills, and embankments.
the greatest component of these recycled organics, with over 1,000,000
tonnes being marketed by the company since its inception.
Biosolids may be
described as the residual component of wastewater treatment. Sometimes
referred to as Black Gold, biosolids are gaining increasing
respect worldwide as natural soil conditioners and fertilisers. The
trend for this valuable growing media may be in part attributed to extensive
and long running research, which has proven biosolids to be an excellent
source of organic matter and plant nutrients.
in the Southern Highlands region (NSW) has shown that stem diameter
of Pinus radiata may be increased by up to 50% following an application
of biosolids to forests. It has been estimated that around 15-20% of
the total nutrients supplied are released each year. This contributes
directly to an increase in merchantable timber. Commercial and private
research is now being turned towards growth studies involving Eucalyptus
spp., given the increasing market interest in hardwood timbers, alternative
power station fuels and carbon sinks. Agroforestry is another growing
market area, with processed organics being applied both prior to plantation
establishment, and between the rows of existing trees.
Within the land
rehabilitation market, organic residuals are recognised for returning
nutrients to the soil. Degraded soils are often unable to support sustainable
pasture or timber growth because of poor soil structure, nutrient depletion,
or perhaps salinity or acidity. Disturbed and degraded land, such as
overburden stockpiles, filled and capped voids and tailings and evaporation
dams, respond to the organic matter and nutrients within processed organics.
Within the Narellan,
Hawkesbury and Hunter regions of NSW, together with the Ipswich area
of Queensland, Bio-Recycle has been a market leader in utilising waste
materials for land restoration projects. In Queensland, Bio-Recycle
has utilised food sludges and biosolids to manufacture bulk composts
for vital topsoil replacement projects. In NSW, Bio-Recycle has been
able to utilise waste materials from coal-fired power stations in conjunction
with organics to develop sustainable pastures.
In the Hunter region,
green waste, fly ash, bottom ash, lime and gypsum have all been blended
with biosolids to improve pasture growth around disused open-cut mining
sites. Studies conducted in this region have revealed a 30% increase
in soil Cation Exchange Capacity (CEC) following the application of
processed organics, with a corresponding positive change in saturation
of individual cations. In addition, the carbon: nitrogen ratio of organics,
especially within biosolids, is close to the 12:1 ratio considered optimal
for healthy soils.
Pasture dry matter
yields from these sites have been up to 100 times greater than on those
areas left untreated. In addition, those areas receiving processed organics
sustained pastures with a much greater legume content, thereby establishing
a much more viable soil-plant ecosystem.
Recycling Park at Ipswich (QLD) demonstrates the companys innovative
approach to recycling. Managed by Bio-Recycle, the former open cut mining
complex utilised many organic waste streams and converted them into
valuable soil amelioration products. These were used for vast land rejuvenation
projects both on and off the 340 acre site.
In many instances,
processing incorporates the natural resources left behind following
mining as natural ingredients. The processed organic wastes have turned
a denuded mining landscape into park-like surrounds. This Recycling
Park project was named by Clean Up Australia Foundation Chairman, Mr.
Ian Kiernan, as the first Clean Up Australia 2001 Project in Queensland.
the recycling of waste residuals is vital to the establishment of
viable pasture and forestry industries upon impoverished soils.