The Jackson family is using green manure and an inter-row cultivator in its organic cropping enterprise; herbicides and windrow-burning in its conventional cropping system; and technology and crop rotations in both farming systems to keep on top of weeds.
The Jackson family is tackling weeds on two different cropping fronts with their willingness to adopt and adapt methods of control bringing hard-won success but leaving no room for complacency.
Brad Jackson says weeds are the biggest problem for both their conventional home properties and their organic venture. Brad operates the conventional properties at Gurley, NSW, 30 kilometres south-east of Moree, in a family partnership with brother Phil and their parents, Peter and Janice.
At Westmar, Queensland, 100km north of Goondiwindi, Brad and Phil and their wives, Jenna and Ashlee, are farming organically, and have adapted a Garford inter-row cultivator from the horticulture industry for broadacre use.
Last year, Brad and his father travelled to a WeedSmart workshop at Wagga Wagga, NSW, and Brad says the practices discussed at the event are encouraging them to incorporate the use of pre-emergent herbicides to control ryegrass and wild oats in winter crops.
Here at home at Gurley, we are getting more winter weed problems, and learning how to deal with ryegrass is probably our biggest challenge, Brad says.
The time will come when we get glyphosate-resistant ryegrass, so we want to use different chemicals and different combinations as much as we can now.
What we learnt from our trip down south was that they are using pre-emergents and mixing up the groups of chemicals they are using so as not to encourage herbicide resistance in ryegrass.
As a contract sprayer, Brad is seeing pockets of ryegrass appear in some of the districts paddocks, including their own.
He suggests it points to the need for harvest weed-seed control, as well as thorough cleaning of machinery before it moves between farms and out of weedy paddocks, as a tactic to include in management options.
Weve got into windrow burning to control harvest weed seeds, and we think we can see a weed-seed impact mill being incorporated into our system in the next five years.
The Jacksons bought a WEEDit optical sprayer in 2016 as a resistance-management tool and Brad says it is delivering savings on chemicals and reducing reliance on glyphosate.
Weve got low numbers of weeds and theyre not seeding, so as we continue to use the WEEDit were hoping the seedbank goes down.
We can use a high rate (still on-label) and spray 10 per cent of the paddock for less than what it costs us to spray the whole paddock at a lower concentration.
Summer grasses controlled in fallow by the WEEDit include barnyard grass, button grass, feathertop Rhodes grass and the occasional pocket of ryegrass, which is adapting its winter habit and appearing more in summer fallows.
The Jacksons grow barley, canola, chickpeas, linseed and wheat as their winter crops and will grow back-to-back broadleaf crops if grassweeds look like they will be hard to control in winter cereals.
We might go linseed and then chickpeas, and use Select®, Verdict®, Treflan® and Avadex® to control winter grasses, with the aim of leaving no survivors, Brad says.
The Jacksons aim for a wheat yield of 3.5 to 4 tonnes per hectare and, depending on the season, usually deliver wheat of 10.5 to 13 per cent protein.
We havent grown a summer crop for 15 years because we risk losing sorghum yield in heatwaves and because we like to hang on to our winter-crop stubble over the summer fallow.
Wheat and linseed are the only two cash crops Brad and Phil grow at Westmar in their organic system, which they have share-farmed since 2014.
Before we started, Phil and I did a tour of organic farming in Sweden, France and the UK to get our heads around what was involved, Brad says.
Their challenge has been to produce high-protein wheat in a cropping system where soil nitrogen is slow to accumulate. With LongReach Spitfire and LongReach Lancer, they are achieving a protein average of 12.5 to 13 per cent and a yield of 1.2t/ha, which they would like to build to 2t as their soil nutrients increase.
Whats important with organic wheat is consistently producing high-protein grain for which we are paid a premium. We dont want really high yields because its too hard to get enough nitrogen back into the soil, quickly, with the system we have for nutrition.
This involves a mix of legumes and grasses grown as a green-manure crop over summer and winter legumes (with a positive impact also on the weed seedbank), as well as compost applied once every four years.
With herbicides out of the equation, and with moisture important to conserve for wheat and the thirsty linseed, the Jacksons have bought a Garford inter-row cultivator to control weeds in their Westmar operation, where turnip and wild oats are the main problem.
Brad and Phil identified the Garford unit as a fit for their operation, even though its only Australian use was in horticulture in Tasmania.
They made us a special unit that can cultivate the 250 to 500-millimetre row spacing needed for cereals.
That said, Brad and Phil have doubled their row spacings at Westmar from 250 to 500mm.
That lower plant population will help us pull through in dry years, Brad says.
The Garford unit also includes a camera, which directs accuracy to within 10mm and leaves 30 to 50mm either side of the row uncultivated.
It is used when the crop height is from 100mm to early head emergence at 400mm.
In the organic system youve got to get weeds under control. Second to that is nutrition.
- More Information: Brad Jackson 0427 544 446, firstname.lastname@example.org
GRDC Research Code: UWA00172