Middlemarch farmers Gus and Tara helped split the Swanni into three pieces and buried each in the ground at their farm the Wandle. Photo: SUPPLIED/SWANNDRI
Outdoor apparell giant Swanndri says an experiment burying a 50-year-old bush shirt into the ground shows the ability of strong wool to return to nature at the end of its life.
New Zealand merino producers Gus Bar and Tara Dwyer first buried an old Swanndri of theirs on their farm in Otago's Middlemarch in 2022 to see how it would degrade over time.
Sandwiched in mesh wire and buried 30 centimetres deep, the final piece of the 31-micron strong wool shirt was dug up in October and showed a high degree of breakdown.
Swanndri head of marketing Jenny Drinkwater said while the project was more anecdotal than scientific, it showed how fast strong wool could break down in nature.
"It degraded really fast actually which is incredible for something that was so durable; it's been worn regularly for 50 years," she said.
"Within about nine months of the first burial, we saw some really significant degradation. We saw worms moving through the fabric and eating the fabric and returning those nutrients to the soil."
Photo: SUPPLIED/SWANNDRI
She said it had degraded even more since then.
"Now two years later, it's pretty much gone, apart from this bright red synthetic patch that's still as good as the day it was made, I guess."
Drinkwater said it showed how useful strong wool could be while also being gentle on the planet towards the end of its life.
"I think the results show that something made out of strong wool can have such a useful and hard-working life, but has a circularity about it and a limited impact at the end of its life."
Drinkwater said the original bushshirt was first designed in 1913, then re-designed in 1927 with a hood, a laced front and long sleeves.
She said the product was unchanged since 1927, though the manufacturing of most Swanndri products were moved offshore in 2005.