Timing boosts irrigation gains

TASMANIAN farmers are often guilty of starting irrigation too late.

That was the yield-boosting message from Ag Logic consultant Marek Matuszek, who leads the company’s soils and ag monitoring services.

Mr Matuszek was one of seven speakers at the Grains Research and Development Corporation’s Grains Research Update at Campbell Town on Wednesday, which attracted more than 60 farmers from across the state.

 “If you want that record bean crop, or the best from any cereal crop, there could be just a couple of weeks in it to get irrigation started at the right time,” he said.

“It doesn’t matter if it’s rained or what you see on the surface – you need to understand what’s going on more than 30cm below.”

While many farmers use technology to monitor soil moisture, Mr Matuszek encouraged those who don’t to “at the very least dig a bigger hole”.

“Take a shovel and have a look deep. Dig more holes to see what’s going on in different areas,” he said.

“From my experience, this kind of information is underutilised in cereal crops because they’re seen as low-value compared to spuds, poppies and dairy.”

In a Southern Farming Systems trial at North Motton, 25mm of irrigation during grain fill delivered a 1.5 tonne-per hectare yield increase.

“Irrigating at the right time allows the soil to hold water more easily. As the soil dries out, it becomes more hydrophobic and loses that ability,” he said.

“Some of the sandy, loamy soils in the Midlands, if they dry out too far, get poor infiltration.

The water bypasses the top 30cm – right where it’s needed.”

Mr Matuszek also discussed when it’s appropriate to allow soil to dry and crack open.

“Careful irrigation management can minimise yield loss by encouraging deeper root exploration while still pro viding enough moisture for growth,” he said.

“The key is to apply irrigations small enough that they only refill the shallow soil layers.”

Other presentations at the conference covered the impacts of waterlogging on barley, canola and faba bean; the use of crop flowering calculators to optimise sowing dates for wheat, barley and canola; and effective grazing without compromising grain yield.