For brothers, Tim and Stuart Plant, of Manangatang, Victoria, the integration of GPS technology into their 3500ha cropping enterprise has been something of a journey.
Like many farmers they started with light bar guidance largely for boom spraying. It was easier and more accurate than using a foam marker, and served them well for two or three years. But it still required fairly intense concentration.
GPS steering offered to solve that problem and they stepped up to an EZ Steer unit that operated directly on the tractor’s steering wheel. Tim refers to it as the ‘shirt tearer’ for its tendency to catch and chew up the driver's sleeve.By this stage they had moved to continuous cropping and saw the advantages that two centimetre precision could provide, especially for inter-row sowing. This led to the purchase of a Farm Pro RTK system using two base stations to cover the 20km north south spread of their various holdings.
In 2008 they upgraded yet again coupling a Farm Pro 2cm unit to a new three bin Simplicity air seeder with linear actuators and variable rate technology.
Huge fertiliser savings
The results have been truly astounding. Fertiliser savings alone will pay for the new air seeder in two seasons. The Farm Pro both steers the tractor and continuously adjusts the seed and fertiliser application rates using a prescription map derived from their 2007 harvest yield map.
"We’d bought a Case 2388 header that came with yield monitoring as standard. It was a pretty basic way of coming up with a prescription map. In an ideal world we would’ve put the GPS unit on the ute and driven the paddocks, but we didn't want to get bogged down in the process – you could spend one year on it.
"And I reckon the yield monitor picked up stuff we wouldn't have seen anyway," Tim added.
The prescription programme was set to provide a 20 percent variation in seed application while fertiliser varied from 0-70kg/ha.
"That's where there the big savings came from," Stuart said. "There's places that haven't grown a crop for years in these dry conditions - we didn't think there was any point putting any fertiliser there. That allowed us to increase the rate where we know we can always get a decent crop.
"In this country you can go from the worst to the best in just 50 metres. It mightn't be the same where you have uniform soil types but in the Mallee there’s the opportunity for massive savings."
Tim said the brothers now realise how much fertiliser they have wasted over the years.
"Even with the dry year and especially the spring, we still averaged 2t/ha. Putting out more fertiliser wouldn't have made any difference."
Big difference with minimum tillage
“Minimum tillage has made a huge difference. We wouldn't be growing the crops we are on this sort of rainfall without the technology advances of the last 10 years. It's cost a lot of money getting there though."
The brothers use a 17m Flexicoil bar with knife points aiming for about 120mm penetration. They spent three or four years dabbling with minimum till but have now been using it across the whole farm for five years.
The last livestock left the property during February but they are trying to establish salt bush cover on 200ha of degraded land, and if successful, lambs might make a comeback.
Apart from the dollar savings as a result of the elimination of overlap and reduced fertiliser usage, both Tim and Stuart are both very enthusiastic about the stress reduction. 
"We do a lot spraying at night to beat the heat and that's where you really notice it. Driving is nowhere near as hard and I reckon that we can do maybe 10% more each day."