Mechanical weeders fell out of use when targeted herbicides arrived, but with the build-up of undesirable ground chemicals, the robots are set to make a comeback.
Mechanical weeding has obvious appeal for organic farmers, they deliver a safer weed control method.
But in addition, as herbicides are becoming less effective, mainstream growers are also looking for alternatives.
And there are many additional benefits mechanical weeders can offer such as an improved water infiltration and better rooting.
These next generation weeders aren’t the labour intensive machines of days gone by, they are autonomous systems that promise to revolutionise the way growers manage weeds.
One company with a successful product already on the market is French weeding and cultivation specialist Carré, with its Anatis autonomous weeder.
Powered by three batteries with a charge life of around four hours, the Anatis machine can be controlled via a smartphone or tablet computer.
Either of these links will provide live camera views from the machine and real-time GPS data.
Its wheels are guided via Trimble RTK GPS technology, with accuracy down to sub-2cm levels, while camera vision for weeding is provided by a system that also works to stop the machine instantly should an obstacle be detected.
The machine has 90 degree-rotating wheels for headland manoeuvrability with minimal crop damage.
Three-point linkage-mounted tools can include a comb harrow or an inter-row hoe for up to four rows. Travel speed is approximately 4kph.
As the Anatis robot is connected via smartphone technology to the farm office, it can help with decision-making through monitoring crops and processing of key indicators.
Anatis collects data on the presence of weeds, density and progress of the crop, luminosity, hygrometry and the temperature of the soil and the air.
By working the ground mechanically to weed the soil, the Anatis provides better water infiltration at the foot of the crop and optimises inputs.
Anatis weighs in at 1,000 kg and is 2.2 metres long by 2 metres wide and 1.9 metres high.
Bernoit Carré, who helped develop the robot, said the Anatis was cost effective at its eu$80,000 price, but the return depends on the farm, crop and soil.
However, he said, it is not just paying cost – the main benefit automation brings to farmers is the added value.
Spending 8 hours in a tractor cab, reading a newspaper as the tractor steers by itself using GPS has no real value. Value is spending more time managing crops.
“I see the same with robots in paddocks, enabling growers to do the more important tasks,” he said.
“Robots can also collect data. For example, if you have the system running for 10 years and have seen 2 to 3 wet springs, then you will have the data to help you manage crops when it occurs again.
“Currently, Anatis measures weed percentage and if for example, a farmer wants less than 7% weeds in the crop, it will map those areas that are above the 7% threshold and produce colour maps. In the future, sensors will also collect other information.”
Carré said the Anatis was initially being marketed to vegetable growers, but it can also work in broadacre crops.
One grower has already used it in barley drilled with 19cm rows and a another planned to use it in sugar beet.