Different systems share a common challenge
GroundCover™ Issue: 105 | Author: Rebecca Leigh
Farm owners: Ian and Marilyn Carter
Location: Pine Ridge, New South Wales
Farm size: 2500 hectares
Rainfall: 650 millimetres (summer and winter)
Soil type: black soil
Soil pH: 8 to 8.5
Crop rotations: (winter) wheat, barley, chickpeas, some canola; (summer) sorghum, sunflowers, mungbeans, cotton
Livestock: 300 trade steers
Grower group membership: AgVance Farming group
Ian Carter draws on 35 years’ experience of farming at Pine Ridge, near Quirindi, New South Wales, when he describes current and recent seasons as “erratic”.
“In 2012, we had a wet summer, a wet start to winter, no rain from July to December, floods in February 2013 followed by a very dry autumn,” Ian says. “This is when our zero-till, controlled-traffic system comes into its own to conserve soil moisture. Last year, despite being dry from July to harvest, we achieved 6 tonnes per hectare on subsoil moisture.”
Research by the NSW Department of Primary Industries into volatilisation of nitrogen (N) has given Ian greater confidence about the efficacy of inputs, so he now puts a strong emphasis on late-season application. He applies 40 kilograms/ha of N at planting, putting urea between seed rows with a zero-till double-disc planter, followed by 50 to 80kg of N as the season progresses in a liquid form, using a John Deere self-propelled boom spray with streamer nozzles.
Ten years of yield mapping, crosschecked with soil test sites, allows Ian to target N to zones.
“Instead of a blanket rate, we target areas we know will perform. As well as improving yield in these areas, we save $20,000 a year in inputs.”
His goal is to boost wheat yields to be comparable to sorghum.“We need wheat in our rotation, but yields tend to remain stable while inputs increase. We can achieve yields as high as 7.5t/ha, so strategic nitrogen lets us target higher yields more consistently.”
Farm owner: Ray Harrington
Farm manager: Tim Harrington
Location: Darkan, Western Australia
Farm size: 2000 hectares
Rainfall: 480 millimetres (winter dominant)
Soil type: quick draining gravel
Soil pH: 4.6 to 5.6
Crop rotations: 760ha of Scope canola, 400ha noodle wheat, 600ha Bass barley
Livestock: 2000 DSE of trade wether lambs
Grower group membership: Darkan Farm Management Advisory Service
In Western Australia, Tim Harrington factors a different set of conditions into his nitrogen strategy.
Tim manages 2000ha at Darkan, about 200km south of Perth, as part of a family-run enterprise. The farm is fenced to soil type. He crops 1750ha and grazes livestock on areas that do not return on inputs.
Tim runs a multi-spreader behind an 80-foot Beverly Hydraboom, modified with a second tank for 5800-litre capacity, and a “beefed-up chassis”. This efficient system reduces passes, allows simultaneous application of non-compatible products and can be operated by a self-described “ageing workforce”, saving labour and diesel.
With little summer rain and well-draining soils, Tim relies on 410 millimetres of the annual 480mm rainfall during the growing season. He capitalises on summer moisture by controlling weeds prior to seeding.
The Harringtons previously waited for rain before seeding, but now embrace dryland farming techniques and start dry-seeding from 1 May.
“Poor seasons educated us to put the crop in early, to insulate it against the dry spring,” Tim says. “As long as we receive some rain for grain filling, we see the results. Last year, we achieved our best dry season result – rain was down 100mm, but we averaged 1.8t/ha canola and 4.1t/ha barley.”
Tim now applies N at strategic times to manage dry seasons and minimise leaching in winter.
“The first application is in-furrow. We band 15kg on top, using a compound fertiliser with potassium and nitrogen blended with triple superphosphate for our high-phosphorous-fixing soils. This is followed by 34kg of N five weeks after seeding, and a similar amount again after rain in July or August.”
This meets canopy management targets for malt barley of 800 to 900 heads per square metre, to deliver 4t/ha, 11 per cent protein and minimal screenings, working on the basis that every 1 per cent of screenings is an extra 100kg of unrealised potential.
“If we apply too much N at the start, we waste energy and soil moisture on biomass. We target optimum head numbers, not maximum.”
Tim plans to incorporate results of canopy management field trials conducted by ConsultAg to improve wheat performance.
Farm owners: Graeme and Rowan Moyle
Location: Hamilton, Victoria
Farm size: 2500 hectares (500ha owned, full contract on 2000ha)
Rainfall: 700 millimetres (winter dominant)
Soil type: heavy clay
Soil pH: 5.4 to 5.5
Crop rotations: wheat, canola
Grower group membership: Southern Farming Systems
At Hamilton, Victoria, father and son team Graeme and Rowan Moyle factor in high rainfall and heavy soils on their 500ha farm and the 2000ha they contract crop.
Most of their 700mm annual rain falls in winter, so they rely on laser drains, raised beds and 100mm agricultural pipe with six half-inch pumps to remove water from paddocks. Deep ripping, stone removal and levelling penalises yields the first year, but the investment pays off in following years.
“With a no-till approach after the first year, we achieve good returns in wet years,” Graeme says. “In the 2012-13 season, milling grade wheat averaged 6t/ha and canola averaged 2.8t/ha. Our yield maps show 7 to 9t/ha crops are possible in places, so we aim to lift yields and achieve a consistent 6 to 7t/ha for wheat and 3 to 3.5t/ha for canola.”
Rowan and Graeme have worked with James Stewart of Vickery Bros., Coleraine, for 10 years to conduct deep nitrogen soil tests to assess what each crop removes from the soil and calculate yield potential and fertiliser requirements for the next season.
Their previous approach of applying 100kg/ha of urea before sowing produced too much biomass, so they now split N application, targeting 30 to 50 plants/m2 of canola and 180 to 220 plants/m2 of wheat.
Their strategy is:
- 40kg/ha urea and 100kg/ha monoammonium phosphate, zinc and copper placed below the seed, using a Seed Hawk seeder with Simplicity 6000L triple bin cart and a small seed box;
- 40kg/ha at GS20 to GS28 if more tillers are needed;
- 100 to 140kg/ha of urea at GS30 to GS32 for maximum yield; and
- 40 to 50kg/ha of urea at GS42 to GS48 (depending on ground moisture and potential rain) to increase protein.
After a dry spring in 2012, the Moyles did not apply the final urea in order to avoid pinched grain and high screenings. This year’s dry start also saw a gap in undersowing until 58mm rain fell on 18 May.
Ian and Marilyn Carter,
0428 668 905,
Graeme and Rowan Moyle,
0417 840 230,
Region West, South, North