Bingham Agriculture, Mingay, Vic
Keeping ahead of weeds in the Vic HRZ
Dan and Jill Bingham run a diversified farming operation based at Mingay, in the high rainfall zone of southwest Victoria. They also operate a large-scale contract sowing and harvesting business across farms in southern Queensland, through NSW and Victoria.
Farm manager Sam Sedgwick and cropping manager Tim Dunne are responsible for the day-to-day management of the Bingham’s 5500 ha mixed farming aggregation of owned and leased country.
Crop rotation
The primary crop rotation is 60 per cent wheat, 30 per cent canola and 10 per cent faba beans. The rotation provides flexibility with wheat-on-wheat where possible, otherwise the wheat in the rotation has a break crop of canola or beans. Where required, the system also allows for a double break of faba beans followed by canola.
The long-season red wheats that comprise 60 to 70 per cent of their crop rotation drive the profit for the 5000 ha broadacre cropping program.
“Equally important is the faba bean and canola double-break component of our rotation, particularly for our weed management program,” says Sam. “Canola is a great way to clean grass weeds out of a paddock, and the double-break effect can drive the next three years of wheat production.”
Canola varieties with herbicide-tolerance traits have been critical to the weed control strategy for many years. Starting with triazine-tolerant (TT) canola, then Clearfield canola with imidazoline-tolerance and RoundUp-Ready (RR) glyphosate-tolerant canola varieties were added. The blackleg disease rating of the canola varieties is a key factor when planning the crop rotation for individual paddocks.
In recent years, they have introduced summer cover cropping on a portion of the farm, adding another dimension to the summer weed control program.
“After harvesting our RR canola crops, we spray for weeds and allow the volunteer canola to grow over summer,”says Sam. “The resulting cover crop provides additional high-quality grazing for the sheep, uses up any excess water and keeps the soil microbe populations active.”
Faba bean stubbles provide supplementary grazing for the sheep, and the Bingham’s retain a small amount of grain for finishing the lambs.
Sam says the beans are more difficult to grow successfully in their environment, but as the team gains experience, they are getting better results.
Weed status
Annual ryegrass and wild radish are the main problem weeds on the farm, and they are keeping a watchful eye on brome grass and bedstraw.
Tim says they will actively manage new weed incursions if numbers increase. They are proactive in adopting the WeedSmart Big 6 tactics within their farming system to keep weed numbers low and to extend the useful life of various herbicide modes of action.
“Our independent agronomist, Ben Dumnesy, oversees our annual herbicide resistance and soil testing program and has a key role in our crop rotation planning to ensure we are optimising crop performance and keeping the weed seed bank low across the farm.”
Farm design, drainage and VRT
Bingham Ag’s contracting arm provides sowing, tillage (land preparation and bed forming) and harvesting services to many large and progressive farming operations in eastern Australia. Over many years, this side of the business has allowed Dan to observe and adopt various broadacre cropping practices from other farming regions.
As their cropping enterprise has expanded, they have adopted several innovations in farm layout, variable rate technology, and raised-bed controlled traffic systems. The sheep grazing enterprise is confined mainly to 500 ha of pastures, while the internal fencing on the cropping area delineates management units of around 200 ha each. Bringing together paddocks with different cropping histories has presented several challenges to crop performance and weed pressure that the agronomy team continues to work through.
About half of the cropping area has been developed for improved drainage on heavy clay soils. The raised bed system has overcome issues with poor crop growth and the associated proliferation of weeds, particularly annual ryegrass. The rest of the cropping area is well drained but has benefitted from deep ripping to address soil compaction constraints.
“In 2021, Bingham Ag purchased a new farm, and we soon discovered a 30 ha area with low pH,” says Tim. “We had sown faba beans, and the crop died in that patch while the ryegrass thrived.”
“We have adopted variable rate applications for lime, gypsum and urea, based on soil core samples taken at 10 cm and 60 cm depth on a grid pattern,” says Tim. “When preparing the VR maps, we also consider the yield mapping data and NDVI data from that paddock. We also adjust our seeding rate according to soil type.”
The philosophy behind their adoption of VRT is to ‘spend money in the best way, not to save money’.
“Our aim is to address constraints for each soil type so we can achieve optimal yield,” he says. “Sometimes it is better to take some country out of crop production and invest time and money to maximise the performance of our better paddocks.”
Clean paddocks after HWSC
The first of the Bingham’s three iHSD impact mills arrived in 2018 for use on their own farms and within their contract business. The three headers fitted with the impact mills are part of the Bingham Ag fleet of 25 headers.
Sam says that other growers appreciate the harvest weed seed control concept but generally find it hard to see past the initial outlay and reduction in harvest productivity.
“Headers fitted with the iHSD impact mills use one-third more fuel, and the harvesting ground speed is slower,” he says. “For our farm, HWSC has limited value in the long season red wheat crops because most of the weed seed has shed before the crop is ready to harvest.
However, it is a very effective tactic to deploy in canola and barley when combined with windrowing.”
The real value of HWSC was seen when two of the Bingham’s dirtiest paddocks were as clean as their best paddocks after two consecutive seasons using the iHSD impact mills.
“The two trails of chaff from the mills are visible in the paddock, but no weed seeds germinate,” says Sam. “It is important to have as many weed control tactics as possible in place, and HWSC adds a non-herbicide tool to help control weeds that have evaded herbicide applications during the season.”
Efficacy is small spray windows
In the high rainfall zone, there are very few days during the growing season when the weather conditions are considered optimal for spraying.
To counteract this constraint, Bingham Ag uses their large spray capacity to take advantage of small spray windows with good weather conditions.
“We have three staff members who specialise in spray operations,” says Sam. “We always target small weeds, use high water rates (80 to 100 L/ha) to ensure adequate coverage of the target, and choose nozzles that produce coarse droplets.”
Tim says they are working hard to reduce their overall herbicide use across their operation and have moved away from relying on ‘out-of-the-drum’ solutions to pests and weeds.
“If a broadacre application is not justified, we will patch manage a problem area instead,” he says. “This has worked well with our pest management, and almost no insecticide is being applied these days. We only spray the borders of our canola crops – about 10 per cent of the canola area – and the beneficials have responded. Of our 1400 ha canola program last year, only 120 ha had insect damage.”
From a weed management perspective, this means investing in soil health and growing the best crop possible, so there is less reliance on herbicides.
Each farm has its own water source and mixing station to maximise spray efficiency. Chemicals are delivered to the paddock from a central farm store, negating any need for a fill truck.
“Most of the water used is rainwater to safeguard our tank mixing, and we are fortunate to have ample sprayer capacity, so we operate at optimal ground speed,” says Tim.
Mix and rotate herbicide modes of action
Currently, herbicide resistance is not calling the shots in the Bingham’s crop rotation, but the team considers the resistance testing results when preparing the herbicide program.
“We certainly have some resistance to herbicides, so our focus is on keeping weed numbers low,” says Tim. “The pre-emergent herbicide application is the most important one of the season. We rotate modes of action within the suite of pre-ems to keep our options open. For instance, we save all our Group 1 [A] herbicides for use only in canola.”
A double-knock is applied before planting wheat, but only sometimes ahead of canola.
Crop competition
To suppress weeds and maximise yield, the Bingham Ag team puts great emphasis on their seeding operation.
“We aim for a plant density of 200 plants per m2 in wheat and 50 plants per m2 in canola,” says Sam. “This plant population gives us a dense crop and rapid canopy closure on 250 mm (10-inch) row spacing. We also aim to get the crop in on time and up out of the ground quickly.”
Although row direction is dictated by topography, they prefer north-south sowing where possible, as this helps the soil surface to dry out.
The Seed Hawk precision seeder is excellent on raised beds, where it sows the sides and drains evenly. The tined, parallelogram seeder separates the seed and fertiliser, plus press-wheels and depth control to promote even germination.
Their crops have responded well to variable-rate applications of lime and gypsum to address soil constraints, and they use a variety of nutrient sources to meet their crop requirements.
Livestock, stubble management and stopping seed set
The Binghams run about 5000 sheep on 500 ha of pasture with strategic access to crop stubbles and fodder crops. The merino flock produces wool, first cross-ewes and prime lambs.
Sheep are a cultural part of the Bingham’s business and have a long history in the region. Keeping the livestock infrastructure in use and in good working order means they can quickly ramp up livestock numbers if desired. The infrastructure also adds to the property’s value.
Wheat stubble is burnt after grazing. Every effort is made to ensure the stubble fires are hot to maximise weed seed kill. Removing all crop residue maximises the efficacy of pre-emergent herbicides and promotes even seed placement and crop germination.
“Our wheat crops generate 5 to 6 t/ha of straw,” says Tim. “After three consecutive wet years from 2021 to 2023, the stubble layer was very thick and kept the soil wet and cold, so we burnt most of the farm those years.”
Windrowing, crop-topping, hot stubble burning and grazing all help run down the weed seed bank.
