Autonomous tractor helps lift IWM efficiency

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Image of Beefwood staff Tyson Hunt (left) and manager Glenn Coughran (right).

Beefwood staff Tyson Hunt (left) and manager Glenn Coughran with the Fendt tractor, which can operate autonomously. Here it is being used conventionally to control volunteer barley with a boom spray.

PHOTO: Liz Wells

The use of autonomous tractors and more targeted herbicide applications are allowing a double-knock strategy to displace blanket spraying in summer fallow at Beefwood in north-west NSW

Snapshot

Grower: Gerrit Kurstjens
Property: Beefwood Farms
Farm size: 11,000 hectares
Location: 50 kilometres north of Moree, NSW
Average annual rainfall: 550 millimetres
Soil types: self-mulching grey clays

A camera-controlled spray unit pulled by a driverless tractor has enabled Beefwood Farms in north-west
New South Wales to more economically incorporate double-knock herbicide applications into its integrated weed management (IWM) strategy.

Employed across Beefwood’s 11,000 hectares, the weed-control strategy starts post-harvest with one or two knockdown herbicide applications from one of the operation’s two 48-metre boom sprays.

The autonomous tractor, coupled with the 24m Hayes WeedSeeker®, follows. When timeliness is everything, the autonomous unit can be put to work the moment weeds are tall enough to be detected by the sensors on the unit. With between one and three breaks in 24 hours, it can get on with killing summer weeds in a targeted operation while Beefwood’s staff get on with other jobs.

“It has reduced our chemical costs by allowing us to only spray between two and seven per cent of the paddock,” Beefwood manager Glenn Coughran says.

“While we are using chemical at a more robust rate, we are doing a much smaller area and using double-knock.”

When coupled with the driverless tractor, Glenn says the WeedSeeker® has been able to operate for up to 12 hours between refills, compared with 60 to 90 minutes for the boom sprays.

Resistance concerns

The Beefwood business employs a no-till and controlled-traffic farming system, and produces barley, chickpeas, sorghum and wheat.

“Since it was bought 11 years ago, it hasn’t had a plough on it,” Glenn says.

In its early years, some chemicals with plant-back windows that restricted winter-crop choices were used in summer fallows.

“Through crop rotations, and by rotating our chemicals, we are on top of the weed problem now, but resistance is something we are wary of.”

Species of concern include fleabane, feathertop Rhodes grass and barnyard grass. Glenn says the WeedSeeker® has been effective in controlling these and other species, with high rates of targeted herbicide often followed by a spray with a different preparation as part of a double-knock strategy.

Drier summers

Glenn says a drop in rainfall received over recent summers has been a factor in Beefwood redeveloping its herbicide strategy.

“Using the WeedSeeker® makes us less reliant on residual fallow herbicides, and using those is of concern when we have a low summer rainfall.

“We’ve been through a couple of very dry summers, and haven’t used residual herbicides for that reason; the WeedSeeker® has been doing the heavy work instead.”

Beefwood’s double-knock strategy involves using a selective herbicide to target specific weeds, and then a non-selective spray.

“It’s not that we won’t use residual herbicides, but moving away from them over dry summers leaves your options more open.”

Better for bottom line

He says it also fits with Beefwood’s switch to using as little chemical as possible.

“Blanket spraying dramatically affects our bottom line; the less we have to do of that, the better for us and for the industry.”

The WeedSeeker® was purchased in 2007, and was recently replaced with a WEEDit unit. The autonomous element was added in 2015, when Dutch firm Precision Makers and Beefwood’s owner, Gerrit Kurstjens, got talking.

“Three years ago we were looking at ways to use our current machinery more efficiently, and looking at the possibility of driverless machinery,” Glenn says.

“Gerrit knew about Precision Makers, which was putting autonomous equipment onto golf-course mowers, and that led them to modifying their technology to suit our needs.”

The Precision Makers software is fitted to a Fendt 936 Vario tractor, which pulls the spray unit at a speed of about 16 kilometres per hour.

Weeds that are about the same size as a cup have sufficient chlorophyll to be visible to the unit’s cameras, and are sprayed accordingly.

Track work

Beefwood has recently taken delivery of a John Deere 8345 tractor to be fitted with Precision Maker equipment.

It will be used to pull Beefwood’s 24m WEEDit spray rig and a tram-track renovator at a speed of about 7 to 10km/h.

“After a time, those tracks get very deep, and every few years we need to fill them in; that’s a good job for the driverless tractors.”

Autonomous eyes

When used with the modified tractors, the Precision Makers software will stop the tractor if its laser detects an unmapped object such as a parked vehicle in its path.

“It will attempt to restart twice, and if its laser sees that object is still in its path, it sends me an SMS that lets me know the tractor has shut itself down and needs human intervention to restart.”

Glenn says the use of autonomous machinery is not about reducing staff.

“It’s about reducing chemical inputs, and allowing staff to perform other tasks that have traditionally taken a lower priority than tractor work.”

More information:

Glenn Coughran
gmcoughran@bigpond.com