Support for Queensland’s organics recycling
Granulated compost (left) and mineral fertiliser (right).
The Centre for Recycling of Organic Waste and Nutrients (CROWN) was established five years ago to support organics recycling supply chains. Johannes Biala, Director, looks back at what has been achieved, current projects, and what the future holds.
The Centre for Recycling of Organic Waste and Nutrients (CROWN) was established in 2017 with seed funding from the Queensland Government.
At the time, the government knew that organics recycling activities would have to increase significantly to meet future waste reduction and recycling targets. Hence, the overarching task for CROWN was, and still is, to support and facilitate all organics recycling supply chains and supply chain partners, including generators and processors of organic residues, and users of recycled organic products.
As product quality and the development of agricultural markets was a key focus of this work, it was only logical to establish CROWN as part of the University of Queensland’s School of Agriculture in Gatton, locating it amid Lockyer Valley vegetable growers, close to the diverse agricultural industries on the Darling Downs and at a handy distance to urban and agricultural composting facilities.
Johannes Biala, Director CROWN at the School of Agriculture and Food Sciences, The University of Queensland, says that by the time government seed funding ceased in 2019, CROWN was established as a self-funding unit within the university. This has been enabled primarily by winning grant funding from the Commonwealth Department of Agriculture to develop a Nutrient Calculator for Users of Organic Soil Amendments, and to find an economically viable way of reducing nitrogen losses via ammonia emissions during composting of layer manure.
Johannes says CROWN is still working on both projects, with the prototype of the Nutrient Calculator currently being evaluated by potential users.
He says that as large-scale granulation and pelletisation of recycled organic products for use with air-seeders in broadacre agriculture became a hot topic in the organics recycling industry, CROWN started to characterise and evaluate these products.
“We assessed not only potential phytotoxic effects these products can have on seed germination and early plant growth, as they are placed near crop seeds, but we investigated also their capacity to replace base mineral fertiliser in pot and field trials,” Johannes says.
“Initial results show that compost granules / pellets can have detrimental effects on germination and early plant growth if placed in close proximity to seeds, but also that these products have the capacity to partially replace base fertiliser.”
Aided by two student projects, CROWN recently measured a steady increase of humic acid during the commercial composting of urban organics and a layer of chicken manure over 15 weeks. The amount of carbon in humic acid compounds found in the generated compost represented between 15 per cent and 20 per cent of total carbon.
Johannes says that knowledge of the humic acid content in compost provides not only an indicator for compost maturity and stability, but offers a means of ‘value adding’ by allocating a monetary value to the humic acid, which can be determined by relating it to the price (and quality) of humic acid products currently being sold to farmers. He says that determining the monetary value of humic acid in compost is one of the next tasks for CROWN.
CROWN co-operates with partners in large and small-scale organics recycling activities.
It has worked with Redland City Council to look for options of recovering, processing and using organic residues on Moreton Bay Islands, and subsequently, with help from the Goodman Foundation, has established and assessed a solar-powered, aerated composting system for a community-based food organics recycling project on Karragarra Island.
Through a student project, CROWN is also currently assessing the efficacy and viability of food organics recycling via Community Composting Hubs in Brisbane.
“As organics recycling activities in Queensland are set to advance and significantly expand over the next decade, CROWN stands ready to provide support wherever required along the organics recycling supply chain,” Johannes says.
In March 2023, CROWN will run the Great Aussie Regional Composting Roadshow throughout Victoria, New South Wales and Queensland and the Composting Technology and Innovation Conference in Brisbane.
CROWN is also involved in developing a sensor-aided source-separation system for high-rise buildings; aims to determine the true agronomic and economic value of organic amendments for farmers, and establish parameters for a Circular Economy for Organics; and assess the effects and efficacy of organic amendments when used in minimum till farming systems.
Other projects include expanding the evaluation of various granulated / pelletised recycled organic product applications; continued work on macro (N, P, K) and micronutrient supply from organic amendments and their fertiliser replacement capacity and investigating the cycling and fate of organics amendment derived carbon and nutrients in soil environments.
“Last but not least, we also want to help promote Dry Anaerobic Digestion as a FOGO processing technology with a promising future” Johannes says.