Trial unearths benefits of wetting agents

Claire TyrrellCountryman

Solutions to non-wetting soils in the northern agricultural region are on the horizon, as a trial puts numerous methods to the test.

Growers travelled from as far as Three Springs to Northern Agri Group’s (NAG) non-wetting soils field in Balla this month, an event that attracted more than 40 people.

Balla farmer Rohan Ford worked with the Department of Agriculture and Food (DAFWA) to sow a 15 hectare trial plot to test 18 ways of improving water infiltration in sandy soils.

The trial explored soil surfactants or wetting agents, as well as spading, claying and mouldboard ploughing techniques.

DAFWA senior research officer Paul Blackwell said preliminary results indicated that soil surfactants could be beneficial.

“We have seen some benefits from banded surfactants when lupins were sown between wheat rows, ” he said.

Mr Ford has used soil surfactants for the past three seasons with some success.

He said a main driver of the trial was to test unconventional techniques.

“The purpose is to see the good, the bad and the ugly of claying, spading and mouldboard ploughing, ” he said. “It’s an expensive process and one you can’t turn back from.”

Mr Ford said soil surfactants had worked particularly well in his dry-sown lupin crop.

“Using a wetting agent we can get our lupins established, so we will stay with that until we get some results from the trial, ” he said.

Mr Ford said he was also interested to see the impact of soil surfactants in wheat. “We’ve only used wetting agents in our lupins, but we might use them on wheat if we see better fertility and higher yield from the trial, ” he said.

Mr Ford used a 30-foot Ausplow DBS to apply soil surfactants to his lupins at seeding.

He said the design of his seeding bar had caused some furrow fill, but that was something he could overcome.

Mr Blackwell said zero-tillage farming coupled with dry seasons had compounded non-wetting soil issues in recent years.

“In sandy soils, non-wetting surface layers form from build-up of organic matter, ” he said.

“This has become more complicated in recent years because of no-till farming. The seasons have become drier and farmers have had to dry sow their crops. Non-wetting soils are more of a problem with dry sown crops.”

The research is led by DAFWA research officer Steve Davies and funded by the Grains Research and Development Corporation.

NAG will hold further field days throughout the season as the trial progresses.

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