A project in the Queensland state of Australia is exploring the potential to turn old cotton clothing into nutrients for new cotton plants.
- The project partners comprise: the state government, Better Cotton strategic partners Cotton Australia and Sheridan, circularity expert Coreo, clothing charity Thread Together, and the Alcheringa cotton farm.
- The project has been outlined in a blog post on the Better Cotton website.
The Context: In Australia, much of the soil landscape has low soil carbon So, anything done to feed and keep the soil biology alive will benefit the cotton sector and the environment.
- The microorganisms that drive the nutrient cycles enable farmers to produce crops, including cotton.
- Any leftover cotton fibre from the harvest breaks down in the soil between seasons.
- Action is also needed to avoid clothing going to landfills.
- The project, therefore, decided to explore whether end-of-life cotton products (primarily sheets and towels) could have the same impact, becoming a natural fertiliser for cotton.
The Goondiwindi Project: It began in December 2019 when the Transition to Action (T2A) programme visited Goondiwindi (a rural town and locality in the Goondiwindi Region of Queensland state) to scope possible circularity projects.
- Transition to Action was a collaborative programme among circularity specialists Coreo, the Queensland Government’s Department of Environment and Science (DES) and the local people of Goondiwindi.
- The Goondiwindi Circular Cotton Project was, thus, born.
- The project became a collaboration between Coreo, the Queensland Government, local brand Goondiwindi Cotton, cotton farmer Sam Coulton, Sheridan, Cotton Australia, and Cotton Research and Development Corporation-supported soil scientist Oliver Knox of the University of New England (UNE).
- The mission was to test whether shredded cotton products at end of life could be returned to the cotton fields, offering both benefits to cotton soil health, and a scalable solution to textile waste.
The Trials: The project sourced waste textiles from various sources, assessed and removed certain components, shredded them, overcame transport logistics issues, launched and monitored the trial, collated and dispatched samples, and pulled together reports.
- Through the first trial, the scientists monitored the impact of around 2 tonnes of shredded cotton on soil microbes on just under half a hectare, considering benefits such as carbon and water retention in soils and microbial activity.
- It was also estimated that the trial offset 2,250kg of carbon emissions.
- The Goondiwindi Circular Cotton Project escalated to a field trial for the 2021/22 cotton season. This saw the application of 1.5, 3, 4 and 6 tonnes of cotton waste (prepared as shod) applied in demonstration plots to a cotton field at ‘Alcheringa’ in September 2021, ahead of cotton planting in October.
- Composted cotton gin trash was used as the carrier material to spread the cotton shod. The remaining material was also used to create a strip of approximately 50 tonnes per hectare in an adjacent cotton field as well as to a small patch of stock route. Although these were not the primary focus of the demonstration trial, monitoring these sites was also undertaken.
- Samples were taken in field at the time of spreading, post planting from most of the plots and in late January 2022 – as the crop was approaching cut out.
- The purpose of the demonstration plots were two-fold: (i) show proof of concept, that cotton waste can be successfully applied to the cropping system and, (ii) there was no impact on the crop. Part of the reason for this is that long term benefits from the application of bulky organic fertilisers is known to generally take five to ten years to result in measurable changes.
