Conventional plastic mats not only render soil lifeless but hang around long after they have stopped doing their weed-suppressing job. In contrast, a new weed mat designed at the CSIRO not only biodegrades, but helps the soil by allowing water in and worms to flourish.
Made using high-pressure water jets that turn linseed straw into a compact fibre, the mat (pictured) biodegrades over a few months, trials have shown.
"Other benefits of the weed mat were that it effectively retains moisture, allows rainfall to soak into the soil, reduces evaporation, and boosts beneficial worm activity," research program leader Dr Stuart Lucas said.
"We believe the CSIRO mat will encourage much healthier soil. Unlike other black polyethylene weed mats, which can remain underground for years, the CSIRO mat is made from plant material and will disintegrate and compost into the soil at the end of its life.” The CSIRO also hopes the fibre might be used to make shopping bags.
About 60 million square metres of plastic weed mats are used in Australia each year and most will never completely decompose, says environmental consulting group AgEconPlus, a partner in the research program.
The new mat is due to undergo further trials on broadscale crops and is not yet commercially available.
In the meantime, for a DIY biodegradable weed mat, try a few layers of newspaper covered in mulch.
Or check out the following biodegradable and degradable weed mats already on the market:
By: Simon Webster
First published: December 2012