BREAKTHROUGH research by CSIRO and “tin hats” could be the
next big gains in broadacre agriculture to boost yield potential.
Experimental work by a Department of Agriculture and Food
WA (DAFWA) research team is comparing a CSIRO developed, aqueous based, biodegradable sprayable polymer product to "tin hats" to move water from the top of row mounds and into furrows to increase water availability for broadacre crops.
As reported in the Farm Weekly (Spray on membrane retains soil moisture, Nov 10), CSIRO could be less than two years away from commercially releasing a spray-on, biodegradable polymer product which is currently being commercially evaluated, in horticulture crops in New South Wales and Victoria.
It is hoped the product will provide a temporary barrier to improve soil water availability until the dense leaf canopy shades the ground to naturally reduce evaporation and competition from weeds.
However, DAFWA principal research officer Dr Ed Barrett-Lenard
said it was also investigating its use in the eastern Wheatbelt alongside angled lengths of tin that look like tin hats - to improve water availability at plant emergence, with the aim of
improving water availability throughout the season.
“We are dealing with an incredibly water constrained environment and if we could increase the availability of
water to growing plants and decrease the proportion of that water that evaporates, we would potentially be able to improve yields,” Dr Barrett-Lenard said.
“There is genuine concern about the long-term future of agriculture in a drying environment – we have to learn to do more with less and the kinds of techniques that we are examining are focusing on the critical issue on how to do that.”
The team testing the polymer product, which was applied via a handheld spray pack, at seeding alongside the tin hats at two properties at Bonnie Rock and Kalannie.
The trial also included the “Wesley Wheel” concept, which was designed by Southern Cross grower Callum Wesley, which uses a custom designed seeding bar to create steep inclines in the furrow to harvest water and reduce moisture loss through evaporation.
While the team waits on final results that will follow harvest, Dr
Barrett-Lenard said results taken through the season were “very promising”.
“By increasing the runoff from each side into the furrow, there has been a 40 per cent increase in total biomass production of the plants, with the tin hats giving us the big gains,” he said.
He expected to see not only a change in yields but also a change in the ratio of grain to screenings, with a lot less screenings with better water retention in the plant.
While the trial showed the polymer product was not yet “fit for purpose” for broadacre situations, as it broke down too quickly, he said there was great promise in where the research
That included using the polymer or tin hat application later in the season to promote water availability during grain fill, capturing summer rain into the furrow and reducing evaporation and potential weed control.
There was also the possibility of changing the colour or pigment of both the tin hats and polymer to reduce frost susceptibility if used later in the season.
“There’s a lot of stuff coming out of this and it is very exploratory but the work has great promise and I don’t see
other technologies really on the horizon that gives us this chance of improving yields by 50pc or more if we get it right,” he said.
“If agriculture is going to continue in drying landscapes and is affected by declining terms of trade and climate change we need to be looking for much more innovative solutions.”
CSIRO research scientist Dr Keith Bristow said as part of the research, CSIRO interviewed more than 200 growers to gain an understanding of exactly what the product could be used for and it had been trialled in cotton, melon and sorghum crops.
“The overwhelming feedback from growers is if you make the product, we’ll tell you what it can be used for – they will incorporate it into what they wanted to use it for,” he said.
Dr Bristow said while the product would initially be geared towards higher margin horticultural crops at commercialisation, such as tomatoes and melons, long term he wanted to see its use extend to broadacre crops.
“The problem is that what might necessarily work well in dryland areas won’t work in irrigation, so I envisage that we will see various versions of the polymer for different situations,” he said.
“The ultimate goal is to see it used in broadacre crops and it has been really interesting to see the work by Ed and his team and to see it add value as part of a system to increase water use efficiency.”