
Chris Evans, agronomy/irrigation worker at “Daisy Lodge”, Carrathool, pictured foreground with fellow employee Neil Chessor.
FURTHER trials on a cotton plastic film have sparked interest among cotton growers looking to save water and time during the season.
DC Enviroplas founder David McGrath, originally from Ireland, used his film of plastic for growing forage in cool conditions overseas.
He then brought his product to Australia to assist regions in germinating cotton at the start of the season when it was cooler.
Basically, a thick sheet of plastic is laid over a normally planted cotton seed with slits in it, so the cotton can grow through the sheet.
The plastic film then acts as a greenhouse, warming up the soil and storing moisture, which could otherwise be lost to evaporation and drift.
For southern cotton growing regions, the plastic allows them to plant cotton earlier, despite the cooler conditions they can experience during the normal sowing window.
Since further trials have been conducted on the plastic, Mr McGrath said the product could benefit the whole cotton industry with its water-saving and yield potential.
“We have data to suggest we can eliminate 0.8 of a megalitre in water use per season,” Mr McGrath said.
Trials have been expanded in the past year, testing the plastic in different regions, soils and row spacings.
Currently, there were trials in most cotton growing regions including Warren, Spring Ridge, Hay, Whitton and Cecil Plains, Queensland.
The benefits of the plastic film have also been consistent across all areas, with cotton covered by the plastic showing early vigour.
“Cotton that’s had the plastic film is showing four to five nodes, whereas the open cotton is showing about two,” he said.
“ThatΆs consistent across the board.”
ThereΆs also been a machine developed by Norseman, Edgeroi, which Mr McGrath hopes will make the application of the plastic easier.
The new machine was used on some of the plastic trials in cotton this season and is currently being altered based on grower feedback.
Elders agronomist Heath McWhirter, Griffith, said there was about 20 hectares of trial plastic in the area and growers had started to look into it.
“You get extra vigour and a longer period to let the crops flower,” he said.
“It also contains water on the surface and can cancel out an early irrigation.”
The faster maturity of the crop also has benefits as growers are able to make their final irrigation 10 days earlier.
The benefits of being able to plant earlier had also been a benefit to the Spring Ridge region, said Agromax Consulting agronomist, Sam Simons, Gunnedah.
Mr Simons said with the Liverpool Plains having a short season, even with adequate water to plant, it was not often the areaΆs temperatures were ideal to plant dryland cotton.
“Anything we can do to extend the growing season should enable us to reach our maximum environmental yield potential,” he said.
Because the film provides the soil with a three-degree buffer during the day and six degrees at night, Mr Simons said it effectively insulated the emerging seedlingΆs temperature and moisture.
“This could also have a role in irrigated cotton, as it would enable earlier sowing to make use of planting moisture and potentially save an irrigation to get the crop established,” he said.
Mr McGrath said growers hadnΆt been concerned with the price of the plastic as the costs were equal to about 0.75 per cent of a bale.
“If youΆre picking up two to three bales a hectare, the cost is absorbed,” he said.
Carrathool coming around
IMPROVEMENTS to a good theory would keep Chris Evans, agronomy/irrigation worker at “Daisy Lodge”, Carrathool, on board with the plastic cotton trials.
Under assistance from his agronomist, Heath McWhirter of Elders Griffith, the paddocks at “Daisy Lodge” have been undergoing trials with founder of DC Enviroplas, David McGrath.
Mr McGrath has been trialling his plastic film, which is put over the top of newly planted cotton to heat up soil and store moisture.
Mr Evans has the trial across six paddocks and has noticed good early vigour.
However, he said there were some challenges.
“The theory is good, the application is getting there,” he said.
“The new machine is a lot better than the original concept.”
Because the plastic film stores water in the top part of the soil, Mr Evans said there could be a fit for the film on “Daisy Lodge”, owned by Peter and Caroline Tuohey, if it was to save water.
Mr Evans has been able to avoid doing a flush on the cotton, which has been positive.