Mineralisation of urban waste through composting in agriculture in a circular economy

Australians are looking to recycle organic streams by composting to keep these valuable materials away from landfill. Worldwide, communities are addressing recycling of solids and green organics as cities increase in size and landfill sites become less available. The alkaline nature of many recyclable organics makes them an alternative to lime application on agricultural land while increasing organic matter in the soil and increasing microbial activity (Goswami & Sarma, 2008). Cole (2021) demonstrated the positive impact of compost tea made from high quality thermal aerobic composted green material on improved soil structure, microbial balance and weed management showing it reduced disease pressure in vineyards which led to removal of herbicides and most fungicides from the annual management program both in the vineyards and the grazing property. Yan et al (2013) determined that the major compounds attributing to odour gases in food waste were trimethylamine and ethyl thioether. Ethylbenzene and citric acid were also present at the standard threshold as tested by gas chromatography-mass spectrometry and chemical methods. As the world transitions from coal and oil-based products, agricultural inputs based on organic raw materials become more in demand. This invites an ever-expanding market for trade in renewable, composted amendments for agriculture globally. Composting organics could provide a revenue stream for councils if they chose to compost on site. The large commercial operators have capacity to improve the quality of products coming from raw organics. Value-added products made specifically fit-for-purpose for different agricultural sectors would attract a premium in best practice agriculture.

Audience Take Away Notes:

• Composting is essential for the future of agriculture
• Demonstrates composting helps soil fertility
• Sustainable agriculture
• Cost saving and alternative income stream
• Cleaner food; fewer synthetic chemicals in the environment; better soil health