The Forestry and Land Rehabilitation market for recycled organics is a rapidly growing sector of Bio-Recycle’s land application programme. Tremendous increases in tree growth and trunk diameter have been noted following an application of biosolids.Flourishing, sustainable pastures have been established on rocky, denuded areas such as open–cut mines, closed landfills, and embankments.
Biosolids represent 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. Research conducted 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. Swanbank Environmental Recycling Park at Ipswich (QLD) demonstrates the company’s 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. Bio-Recycle believes the recycling of waste residuals is vital to the establishment of viable pasture and forestry industries upon impoverished soils. |
