From monoculture to masters of plenty
GroundCover™ Issue: 26
There's been a farming revolution on the central southwest slopes of the Riverina in NSW, and few would want to go back to the old days.
Six years ago most farmers in the region followed a simple rotation and a single fixed regime to produce a single grain product, mainly ASW wheat.
Today, having come together as the Tidd and Horan IAMA TOPCROP groups, they are manipulating a wide range of cereal and pulse crops. These include canola, barley, oats, lupins, field peas and faba beans. Growers are now tailoring them with assurance to meet both human and feed market requirements.
In wheat alone, south-west slope graingrowers are producing six different crops, from soft milling wheat to prime, and are investigating export markets for durum, gluten and noodle wheats.
What has made the difference?
In one word, TOPCROP. "Six years ago they were working with totally new crops and flying blind," said the national manager of TOPCROP Ross Cutler. "But since they started working together and applying TOPCROP principles, these groups can plan for a wide range of crops with confidence and predict target yields with scientific precision."
Tidd and Horan coordinate 180 graingrowers in eight TOPCROP groups that lie within a 100 km radius of New South Wales' central south-west slopes. The chief adviser is Terry Horan, whose company Tidd and Horan IAMA has been involved with TOPCROP from the start. He is assisted by AGWEST District Agronomist Peter Mathews.
Enter water-use efficiency
Mr Horan said historically it's been hard to find a unifying factor between those farmers with lower rainfall in the west (450 mm) compared with those at higher elevations in the east (525 mm rainfall). The equaliser has been the groups' discovery of water-use efficiency (WUE) targets and hand-held moisture probes to accurately determine the moisture available to crops at any given time.
Mr Horan said the impetus for investigating water-use efficiency arose out of disappointment.
"In 1997, using TOPCROP formulas for predicting target crop yields we came unstuck because we didn't know the available soil moisture. Our targets proved too high and we ended up applying too much nitrogen for the actual yields."
The groups approached CSIRO for information on the soil moisture profiles from three sites where CSIRO had fixed water probes. The response was "that the variations would be too great across paddocks and soil types for any meaningful use," Mr Horan remembered.
Soil moisture can differ not only based on whether a pasture is annual or perennial, but on such fine details as whether a crop is removed early or late.
A strategy of their own
This started group members thinking. If the measurements needed were so precise, why not use hand-held moisture probes to provide accurate, on-the-spot data?
In 1998, with the aid of WUE targets and handheld probes, one-third of Tidd and Horan group members were able to fill the missing link in TOPCROP yield formulas for their region with amazing accuracy.
TOPCROP recording and monitoring along with rapid advances in technology are revolutionising management practices, says Mr Horan. He cites NIR (near infrared) testing as one of the big success stories in targeting outcomes.
"Growers can now determine with reasonable confidence where grain protein will end up," he said. "It means they can achieve a target such as growing high protein gluten."
Making the most of herbicide rotations is another key area that becomes much easier with regular recording and monitoring. Mr Horan says TOPCROP growers are picking up insect predation as well as herbicide resistance far earlier than in the past as a result of regular, close scrutiny of paddocks.
Contact: Mr Terry Horan 02 6977 2956