Auto steer systems pay dividends for two Scottish growers
Two Scottish growers are appreciating the accuracy and cost savings available from using auto-steer systems. Peter Hill reports
Seeing an operator demonstrating auto steer by driving along with his hands clear of the wheel is becoming a bit of a cliché. But it is a good way of illustrating a technology that promises a whole bunch of benefits – from reduced input costs to drivers being able to step off their machines feeling less tired at the end of a busy day.
For Stuart Davidson, who grows about 930ha of arable crops from Knockothie House at Ellon, 16 miles north of Aberdeen, investing in high-definition auto-steering is a natural progression from other precision farming technologies he employs.
Stuart Davidson (left), with former tractor operator Lee Chapman, reckons having Auto-Guide high-definition GPS-guided steering on his tractors and combines will pay dividends through more accurate tramline spacing and reduced inputs wastage.
But it is also part of a package of investments intended to give the arable business an efficiency boost for the next few years.
“We need operators prepared to use this sort of technology and there are now people who’ve grown up with it and are enthusiastic about using it to do the job right,” he says. “So we’ve adopted auto-steer at the same time as buying new tractors and shifting up from 24m to 36m tramlines to improve our efficiency.”
Mr Davidson is no stranger to precision farming technologies; he already uses yield mapping on the combine, has applied P&K at variable rates for some years and is now trying the same with nitrogen dressings.
Having the Case IH AFS600 terminal installed on the three Puma tractors and Axial-Flow 9010 combine bought last summer has brought improved levels of job recording to help with input costings.
Moreover, Mr Davidson and Craig Hamilton, his business partner in Knockothie Farms, decided to go the whole hog when it came to choosing a dGPS-guided auto-steer system to improve fieldwork efficiency in the production of 560ha of winter barley, 180ha of winter oilseed rape and some wheat sown on heavy ground.
The Accu-Guide system fitted to the three Puma tractors still on the farm and the Quadtrac that becomes the main power unit this autumn, is guided by a high-definition RTK set-up.
“We’ve never used steering guidance and I’ve been put off buying a non-RTK system by the variability you can get relying on remote correction signals,” says Mr Davidson. “Besides, costing the RTK set-up over four years and four vehicles – three tractors and a combine – the figures break down to a quite sensible cost.”
 Using high-definition auto-steer to accurately match cultivation bouts with minimal “safety margin” overlap improves work rates, allows operations to continue in poor visibility and makes life easier for the operator. |
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The Trimble-based Case IH RTK system uses a transmitter to provide extra correction data from a fixed point for a claimed ±2cm accuracy.
Case IH engineers set up the base station on an elevated part of the farm, gaining signal coverage over 480ha of the operation, with a repeater unit picking up the signal and re-transmitting it to cover another 650ha of lower-lying land.
“The coverage is a lot better than I expected and the accuracy every bit as good as I’d hoped for,” says Mr Davidson. “When we subsoiled using it for the first time, the spot-on spacing looked like someone had been in with a tape measure.”
The system has also been used for drilling, which has the double benefit of effortlessly ensuring accurate bout matching, but also establishing accurately-spaced tramlines for all subsequent operations.
“By moving to 36m tramlines we’ve already gained 12ha of ground that we previously put inputs on, but grew no crop on,” notes Mr Davidson. “We’re making the most of that gain by using the high-definition auto-steer to avoid misses and excessive overlaps, savings inputs, including fuel, gaining output and easing the driver’s tiring workload.”
Further south, at Gilston Mains near St Andrews, East Fife, Edward Baxter hopes to use accurate auto-steer to eliminate tramlines altogether, along with the soil erosion problems associated with them.
The first unit he bought from Soilessentials last summer improved drilling accuracy; and the on the strength of that, a second MojoRTK system was bought for ploughing and spraying.
Gilston Mains, a LEAF integrated farm management demonstration unit, is taking part in a LINK-funded research project with the Scottish Crop Research Institute to combat the erosion caused by tramlines.
“The easiest way to avoid the erosion they cause is to eliminate tramlines altogether,” says Mr Baxter. “But to do that, we needed an accurate steering system.”
While minimum tillage establishment systems are used for some crops, the plough still has an important role to play and a move to on-land ploughing to cut compaction has been helped by the auto-steer system.
The simplicity and relatively low cost of the MojoRTK package, produced by Leica Geosystems, made it an attractive option at less than £10,000, despite being an RTK system with a claimed ±5cm accuracy with 99% reliability.
“Accuracy is important to us; we’re hoping to capitalise on it by reducing inputs over time,” says Mr Baxter. “The auto-steer systems proved reliable in the first season, when we used it for all of our autumn establishment work.”
Another attraction is the way the MojoRTK is designed to minimise cab clutter – the guidance screen and controls are packaged in a neat console that fits into a standard radio slot.
It is also straightforward to install and operate, says Mr Baxter: “You drive into the field, set up the base station, pick up the signal and off you go.”