BIG gear is used to plant accurately at Ungarie in NSW, reports MARK SAUNDERS

Graham Barron refers to his farming system at Ungarie in NSW as "demand agriculture".

Sowing about 20,000ha of grain a year on properties around West Wyalong, Graham wants to participate as much as possible in what he calls the food-value chain.

"I aim to keep as much control as possible of the grain by storing it on-farm and staying in touch with the end users of the product," Graham said.

The value chain for Graham starts each autumn when the grain crop is sown using large-scale broadacre machinery such as three Vaderstad SeedHawk air seeders and three tracked John Deere tractors.

"Importantly, our key contractors which assist in the farming operations, have adopted similar technology," Graham said.

The biggest of the Vaderstad air seeders has a sowing width of 24.4m while the biggest tractor is a John Deere 9630T.

The 24.4m Vaderstad is used for direct drilling crops where tillage is kept to a minimum.

The huge air seeder, with triple bins, can carry about 21 tonnes of grain and fertiliser when full.

Despite some of the machinery's large size, Graham said sowing is all about accuracy.

"We are sowing at three plant rows to a metre and at depth variations of 10mm so the gear has to be very accurate as well as large scale," Graham said.

"At times when planting, we are really only just covering the seed with soil.

"It's a minimal approach to tillage as we have to conserve soil moisture and organic matter so we are usually sowing into stubbles."

Graham said simplicity was also a key feature of the air seeder.

"We looked at many models of air seeders and the Vaderstad SeedHawk has what I believe is one of the simplest parallelogram designs around.

"That's a big factor when it comes to maintenance, especially on a machine that's more than 20m wide. Plus the Vaderstad has a press wheel depth setting design so it's very accurate."

Graham said the accuracy of the machinery is further enhanced with John Deere's GreenStar global positioning satellite technology.

"The business also runs four other John Deere tractors that haul trailed sprayers, including a 9000-litre capacity Hardi with a 36.6m boom. Having the GPS compatibility across the tractor and harvesting fleet is a real bonus as we can use it on pretty much any of the machines."

Graham is a fourth generation farmer in the Ungarie district and he has seen plenty of change in the way the land is farmed.

"There has been enormous change in farming practices, from the machinery and the way the ground is worked or more importantly not worked, to participating in marketing and talking to end users."

Another change to Graham's cropping is the introduction of variable rate technology, where inputs such as fertiliser are applied at different rates on the go, according to crop yield data gathered at harvest.

"The crops were yield mapped for the last two harvests and this year we will be sowing using the variable rate application technology for the first time," Graham said.

"We combine the harvest information with soil tests and we utilise an agronomist to make sure our applications are accurate."

Organic fertiliser has been experimented with but mostly the fertiliser of choice is mono ammonium phosphate.

"The country has a history of higher fertiliser application rates of about 80kg/ha but as it's been so dry in recent years, it is getting less and less.

"Last year we applied no fertiliser at all to some paddocks and you could not tell the difference in the crops at harvest," Graham said.

"I suppose it's a reflection of the changes implemented that we can grow a reasonable crop on less rainfall."

Graham said last year's crop yields varied from 2.5t/ha to zero with an annual rainfall of 283mm and a growing season rainfall of 189mm from April to the end of October.

The property's average rainfall is 450-500mm but Graham said six of the past eight years had been well below average in terms of rain and crop yields.

Graham said being able to harvest a crop at all last year was testimony of improved cropping practices.

"We inter row sow crops and direct drill them into stubbles to retain as much soil moisture as possible.

"All we need is a decent year of rainfall to take advantage of the system."