Joining the global race for plastic alternatives, the CSIRO has developed a sprayable biodegradable membrane called TranspiratiONal-SBM. It’s a ‘spray and walk away’ solution to mimicing the benefits of plastic – controlling weeds, increasing crop yields, conserving water – without the massive environmental impact.

There are many benefits to using mulch, including soil temperature modulation, enhanced produce quality, improved soil water management by reduced evaporation, reduced fertiliser leaching, earlier crop production, higher yields, reduced soil erosion, better management of certain insect pests and fewer weed problems. Plastics have been widely used because they are quite inexpensive and there are well-developed crop management systems, including tractors and other machinery, specifically designed to work with and through plastic mulch.

However, due to the fact plastic is made from petro-chemicals, releases toxins from manufacture to field, is non-newable and is not biodegradable, it’s placing a huge toll on the environment. Of course, there are other issues around disposal: it can’t be disposed of through burning due to off-gassing, it can’t be put into landfill due to the length of time it takes to break down and recycling is difficult due to organic, moisture and chemical residues. So, an alternative will be a huge win for the environment and the grower.

The new TranspiratiONal-SBM product is currently being trialled by the Department of Primary Industries and Regional Development (DPIRD). It’s classified as a novel, semi-commercialised Sprayable Biodegradable Polymer Membrane (SBPM). Designed by the CSIRO, DPIRD is supporting its use as a tool for sustainable farming.

Currently there are two demonstration sites on butternut pumpkin and tomato crops in Carnarvon, two table grape demonstration sites in the Swan Valley and two wine grape vineyards in the Margaret River and Frankland River regions. There is also a trial to assess the suitability of SBMM for topsoil stabilisation during the establishment of carrot seedlings cultivated in sandy soils.

DPIRD has been collecting final crop data to incorporate with additional measurements, such as soil moisture, soil temperature and soil EC, taken during growing seasons to understand the full impacts of the biodegradable mulch as compared to plastic mulch and other conventional practices.

With irrigated crops in the South West of Western Australia, including wine and table grapes, citrus and vegetables, vulnerable to climate change and representing $900m to WA’s economy, we have our hopes pinned on positive results.

Initial trials have been positive, with biodegradation rates of the membrane ‘tuneable’ with the polymer substrate dispersing and breaking down naturally after a crop cycle with the help of a soil microbiome.

DPIRD supports the adoption of biodegradable mulch technology in vegetable and perennial fruit enterprises, and is happy to talk with interested growers on the results that have been attained in on-farm trials.