It is well documented that automatic guidance systems offer significant improvements in the accuracy of field operations. But less is known about the impact this efficiency will have on growers’ bottom line.
This was the problem facing James Evans, farm manager at Lowley’s Farm, Great Leighs, Essex and Strutt and Parker’s Richard Means.
Several people had told them an auto-steer system would improve efficiency, but they weren’t willing to take the plunge until they had some accurate figures to go by.
So they approached John Deere and, after securing two demonstrator units, embarked on a two-year trial to see if auto-steering systems were worth the investment.
One year in the system has reduced fuel consumption by 10% and reduced time spent on field operations by 11%. “Over the farm’s 860ha this works out to be a saving of £5000 a year,” says Mr Means. “It has also reduced the farm’s working area by 1-2%.”
The initial investment can be high, but the study is showing that it can pay for itself quickly, he adds. “It would only take two to three years to recoup the £13,000 investment.”
The farm was split into two similar blocks with one half farmed using GreenStar and the other without. To improve accuracy, fields were matched according to size, soil type and number of obstacles. “We tried to make it as accurate as was practically possible, but it had to fit around existing farm operations” says Mr Evans. “Next year fields will be reversed to remove the field factor from the results.”
The quantity of diesel used and the time taken to complete each task was recorded, he says. “We would start each operation with a full tank of fuel and fill up as soon as the job was completed. “It was a bit of a pain but meant we could keep an accurate record of fuel used.”
Results show that the GreenStar SF2 system cut field operation times for all for the processes tested and reduced diesel consumption for most.
These benefits were most noticeable on the 30ft cut Lexion 580 combine, says Mr Evans. “The header was always full which reduced the number of passes saving time and fuel.”
It also made a considerable difference when pulling a 3.2m Gregoire Besson Discordon behind the farm’s John Deere 8330, he says. “On average we saved 3.48l/ha of diesel and 2.64min/ha.”
Third most conclusive was pressing, where auto-steer saved 0.84 litres of diesel/ha and 1.70min/ha.
But once tramlines were established, the benefit of using GPS was significantly reduced, he says. “As your path is already marked out there is no benefit from using guidance and in some cases it can pull you off line.” As a result we found GPS offers no fuel saving on spraying and fertiliser applications, he says.
Surprisingly, there was also little to be gained when drilling with the 6m Horsch Sprinter. “Before we started we measured our tramline centres and they were bang on 24m,” he says. “Therefore there wasn’t much margin for improvement.”
But unlike diesel consumption, operation times were reduced for all tasks when using GreeenStar. “The tractor would automatically snap onto the right path saving time on headlands,” he says. “This was very quick with the fully integrated system, but took a bit longer with the universal system,” says Mr Means.
This time saving allows us to concentrate on other jobs,” he says.
There were also “soft benefits” associated with the system, but these were more difficult to quantify, says Mr Evans.
First, he reckoned operators were less fatigued when using the system. “People who have used the system say they are less tired at the end of the day,” says Mr Evans. “It’s ultimately a money saving exercise, but it is great that you can get these additional benefits too.”
The reduction in working area would also reduce the wear on metal parts, says Mr Means. “The distance-wearing metal parts such as cultivator tines travel through the soil is reduced so this is bound to offer a cost saving.”
Both agree that the results are conclusive. The two to three-year payback is attractive, says Mr Evans. “And from a farm management point of view it has shown us the real price of the system per ha.”
It gives us the confidence to recommend the system to other farmers, says Mr Means.