The Glenvar Bale Direct System developed by the Shields family at Wongan Hills (WA) consists of a large square baler directly attached to the harvester that constructs bales from the chaff and straw residues during harvest.
This system serves to both capture weed seeds and bale harvest residues for livestock feed. AHRI studies have determined that 95% of annual ryegrass seeds that enter the front of the harvester are collected and removed from fields using this system.
It’s a great system for those who have access to a market for the bales close to their farm.
What can I do at harvest to reduce my future weed burden?
As crops mature and harvesters begin reaping, consider the potential fate of seeds ripening on weeds that escaped in-crop control measures.
Peter Newman, WeedSmart’s western extension agronomist, says harvest time is an important opportunity to assess weed burden across the farm and be proactive about driving down the weed seed bank.
“Harvest can either be a super-spreader or a weed suppressing event,” he says. “Small patches of weeds can quickly expand when seed is blown out the back of the harvester. On the other hand, the harvester can be a powerful weed management tool if any one of the harvest weed seed control options are implemented.”
WeedSmart’s western extension agronomist, Peter Newman says efforts made to reduce the spread of weed seed at harvest will soon pay off for growers.
Australian growers have led the world in inventing and adopting harvest weed seed control tools such as impact mills, chaff carts, chaff decks and chaff lining, all of which can reliably destroy over 90 per cent of the weed seed that enters the front of the harvester.
“In addition to harvest weed seed control there are several other actions in the WeedSmart Big 6 that growers can implement just prior to, during and immediately after harvest that will make a measurable difference to the weed burden in future growing seasons,” says Peter. “The WeedSmart Big 6 tactics are scientifically-proven to reduce the risk of herbicide resistance through diverse herbicide use and cultural control to prevent weed seed set.”
What can I do before harvest to manage late emerged weeds?
In brief: Scout for and map weedy patches. Consider sacrificing small areas of high density weeds. Swathing can be a very effective way to stop seed set of late emerged or resistant weeds. Collect weed seeds for herbicide susceptibility testing.
The details: Growers across Australia use a variety of methods to map weeds – from the simple to the sublime. ‘Dropping a pin’ using the tractor’s GPS mapping system as you travel through a weedy section when spraying or harvesting is easy and provides useful information about the distribution of weeds in the paddock. Many growers have their own drones and use them the collect images or video footage of the crop that can be viewed or analysed to identify high density weed patches.
Collect seed for herbicide susceptibility testing – knowing what still works is vital information for planning next season’s herbicide program. There are three herbicide testing facilities in Australia that are equipped to test weed seed samples – Plant Science Consulting, CSU Herbicide Resistance Testing and UWA Herbicide Resistance Testing.
Collecting weed seed before or at harvest is the most common method used. The collected seed must be mature, from green to when the seed changes colour. Before harvest, collect 30 to 40 ryegrass seedheads or several handfuls of wild oats seed. After harvest, it is common to find seedheads still in the paddock or samples of contaminated grain can be sent for analysis.
Keep samples from different locations separate and details noted on the bag. Only use paper bags (double layer) to collect and send seed samples. Ensure bags are sealed so that the samples don’t mix during transit.
Which harvest weed seed control tool is best for my situation?
In brief: There are six harvest weed seed control tools used in Australia – impact mills, chaff decks, chaff lining, chaff carts, bale direct and narrow windrow burning. Choose the one that best suits your system and budget.
The details: Impact mills are best suited to continuous cropping situations. Residues are retained and evenly spread. Chaff decks have lower capital cost and are well-suited to controlled traffic situations. Chaff carts are popular with grain producers who also run livestock. Bale direct is also expensive but has a good fit in locations where there is access to straw markets. Chaff lining is currently the best ‘entry level’ system and can be used in CTF or non-CTF systems, with best results where the harvester runs on the same track each year. Chaff lining has essentially superseded narrow windrow burning, overcoming the time required and risks involved in burning and reducing the loss of nutrients from the system.
If you haven’t used harvest weed seed control tools before, it doesn’t take long to build and fit a chaff lining chute ready for use this harvest season.
What should I be ready to do straight after harvest?
In brief: Spraying weeds immediately after harvest is fairly common practice. Weeds present may be close to maturity or fresh germinations of summer-active weed species.
The details: Some growers get in early with knockdown herbicide applied under the cutter bar when swathing barley or canola. Consider using the double knock strategy, heavy grazing pressure and possibly a soil residual herbicide that is compatible with your planned crop rotation. Pay particular attention to any weedy patches identified before or during harvest. Stopping seed set at every opportunity is the crux of an effective weed management program.
Give some thought to what might be the underlying cause of weedy patches – fixing problems such as pH and soil nutrition imbalances, waterlogging and spray practices that routinely deliver low doses of herbicide.
Harvest weed seed control in a nutshell
*Note: In Australia we call the whole machine a harvester, not just the cutting front.
At harvest time many weeds that have grown in the crop still have seed held in the seed head. These seeds enter the harvester along with the grain and most exit the harvester and are spread across the paddock in the chaff and straw.
Collecting these weed seeds at harvest and either destroying them or depositing them in a known location where they can be monitored and controlled later, is an excellent way to stop weeds in their tracks.
Brome grass is the most costly weed for Mallee farmers to manage, even though herbicide resistance in brome grass is currently low in the region.
If you are considering adding harvest weed seed control (HWSC) to your weed control program there are excellent resources on the WeedSmart website to help guide you through the initial decisions and the implementation of this important weed control tool.
Decide on which system fits your farm best.
Get maximum weed seed into the header.
Know how to manage the collected weed seed.
Which system is best?
HWSC is being rapidly adopted in Australia and other countries around the world. There are six systems currently being used on Australian farms and they have all been developed by farmers. Research has demonstrated that all are very effective weed control tactics, achieving over 80 per cent control and for some nearly 100 per cent.
There are six systems currently used to collect and manage weed seed at harvest:
chaff decks (chaff tramlining)
narrow windrow burning
While they are all effective, they vary considerably in capital and ownership cost, nutrient removal costs, operational costs and labour costs. Some HWSC tactics involve the purchase of substantial machinery – such as an impact mill, chaff cart or chaff deck – but the operational and labour costs might be lower than methods such as narrow windrow burning, which involves low set-up costs but higher nutrient losses and labour costs associated with burning. Invariably narrow windrow burning is the most expensive option in the long-run due to the high nutrient removal cost.
To calculate the cost of each method for your farm you can use a calculator developed by AHRI’s Peter Newman. https://www.weedsmart.org.au/calculating-the-cost-of-hwsc-for-your-farm/
The HWSC tools all involve some modification to the harvester. The simplest modification is for chaff lining and narrow windrow burning, where a simple chute is attached to the rear of the harvester to direct the residue into a band on the ground, running the same direction as the harvester has travelled. These chutes are often constructed and fitted on-farm.
All the other systems are commercial modifications that are fitted to the harvester – chaff decks and impact mills – or trail behind the harvester – chaff cart and Bale Direct.
Videos from the HWSC course outline the science and practice of HWSC https://www.weedsmart.org.au/resources/hwsc/
Calculating the cost of HWSC https://www.weedsmart.org.au/calculating-the-cost-of-hwsc-for-your-farm/
Stepping into chaff lining https://www.weedsmart.org.au/stepping-into-chaff-lining/
Using your harvester to destroy weed seeds https://www.weedsmart.org.au/using-your-harvester-to-destroy-weed-seeds/
Get the weed seeds into the header
Harvest weed seed control only works on weed seed that enters the header. Getting the weed seed into the header relies on the seed being held in the seed head at the time of harvest. The seed head must also be at harvestable height.
Consider the weed spectrum and the likelihood of seed capture. Even if some seed has shed, chances are there will be other seed heads that have not yet shed and even this will assist with reducing the amount of seed entering the seed bank.
There are four chaff-only systems and two all-residue systems.
The chaff-only systems – chaff carts, chaff lining, chaff decks and impact mills – require the harvester to be set up to separate chaff and straw, and to keep the weed seed in the chaff stream. This may require modifications to the harvester rotor and sieves and the installation of a baffle to keep the weed seed in the chaff stream.
If you choose the Bale Direct system or narrow windrow burning, all the straw and chaff ends up in the same place, so no other modification to the harvester is needed.
Harvester setup for HWSC https://www.weedsmart.org.au/webinars/harvester-set-up-for-harvest-weed-seed-control-hwsc-for-all-header-colours/
Getting weed seed into the chaff stream https://www.weedsmart.org.au/setting-up-harvesters-to-capture-weed-seed-in-the-chaff/
Using HWSC in different weed spectrums https://www.weedsmart.org.au/is-harvest-weed-seed-control-a-real-option-for-managing-northern-region-weeds/
Manage the weed seed after harvest
If you choose an impact mill as your HWSC tool then the tactic is completed in one pass at harvest, with nothing extra to do. All the residue is spread in the field and the weed seeds are rendered unviable.
All the other HWSC tools involve some action after harvest to remove or destroy the weed seed collected at harvest.
Chaff decks deposit the weed seed-laden chaff in one or both harvester tramlines or wheeltracks. Some growers find that the chaff rots and the weed seeds die, but in other environments growers find that it is necessary to control weeds that germinate in the tramlines using herbicide or non-herbicide tactics applied just to the tramlines.
Chaff carts can be emptied as they fill in the paddock or emptied at a central point. Many growers use chaff piles as a high nutrient value stockfeed, others burn the piles and others leave them unburned in the paddock and sow through them the following season.
Chaff lines are usually left unmanaged with the expectation that the following crop will provide adequate competition to the weeds to minimise weed growth and seed production.
The Bale Direct system results in large bales of crop residue that can be sold into suitable markets. Distance to market is usually an important factor in the success of this system for HWSC.
Narrow windrow burning uses fire to destroy the weed seed in the Autumn following harvest. There are significant labour costs and safety risks to consider along with the loss nutrients and ground cover.
Key resources to learn more:
Diversity Era online course – Harvest weed seed control 101 https://www.diversityera.com/courses/harvest-weed-seed-control-101
Kondinin Group Residue Management at Harvest – Weed Seed Options research report https://www.weedsmart.org.au/app/uploads/2018/06/RR_1802_weedsmart.pdf
Kondinin Group Harvest Weed Seed Warriors research report https://www.weedsmart.org.au/app/uploads/2020/05/RR_February_2020_Weedsmart.WS_.2020.pdf
Chaff decks and chaff lining in a high rainfall zone https://www.weedsmart.org.au/case-studies/esperance-growers-using-chaff-decks-and-chaff-lining/
Keeping pressure on brome grass with HWSC https://www.weedsmart.org.au/case-studies/bruce-family-alford-sa/
Which harvest weed seed control tool is right for you?
“To win the war you must win the battles. Harvest weed seed control is an important battle” – Ray Harrington, WA grower & inventor of the Harrington Seed Destructor
Our harvest weed seed control special edition e-news was included in a recent GRDC Weed Alerts email. We felt that it’s a handy resource that was worth including on our Bulletin Board. Read on for more info and our “which HWSC tool is right for you” checklist!
WeedSmart enews #8
Welcome to our harvest weed seed control (HWSC) special edition (we like to get in nice and early).
We’ve included links to further info on the five main HWSC tools, plus a quick little checklist to work out which tool is right for you.
Remember, if you have any questions, feel free to contact us on Twitter, Facebook or via the contact form on this website.
Which HWSC tool is right for you?
Follow the links below for more info on the HWSC tools relevant to your farming operation:
Do you have sheep? Chaff cart / grazing dumps
Are you a CTF grower? Chaff deck
Are you a low cost, low rainfall grower? Windrow burning or chaff cart
Are you hell bent on residue retention (are you a stubble hugger?)? HSD
Are you CTF with a disc seeder? Chaff line / windrow rotting (early stages – stay tuned!)
Do you have a market for straw near your farm? Bale Direct
Narrow windrow burning
By mounting a chute to your grain harvester, all of the exiting chaff and straw residues are concentrated into a narrow windrow about 500-600mm wide which is later burnt. There’s a 6 step intro vid, chute CAD drawings, plus tonnes of other handy resources over at the website.
Chaff carts are towed behind harvesters to collect the chaff fraction as it exits. The dumps are later burnt or grazed. Super quick video, handy financial factsheets and more are available for you here.
Harrington Seed Destructor (HSD)
A unique system developed by the awesome Ray Harrington that processes the chaff fraction to destroy any weeds before returning the material to the paddock. There is no need for any post-harvest operations and all harvest residues are retained (win/win!). More info? Here you go.
The Shields family in WA developed the Bale Direct System. The large square baler is attached directly to the harvester and constructs bales from the chaff and straw residues. For more info plus resources click here.
Funnel seed onto tramlines
In controlled traffic farming systems, weeds are funnelled onto an inhospitable environment – compacted by soil and run over by machinery (weeds deserve it). Find out more
Miss or want to review our harvest-themed webinars?
Recordings are available here.
Bale Direct System
An alternative to the in-situ burning or grazing of chaff is to bale all chaff and straw material as it exits the harvester
The Bale Direct System developed by the Shields family at Wongan Hills (WA) consists of a large square baler directly attached to the harvester that constructs bales from the chaff and straw residues during harvest.
This system serves to both capture weed seeds and bale harvest residues for livestock feed. AHRI studies have determined that 95 per cent of annual ryegrass seeds are collected and removed from fields using this system. It’s a great system for those who have access to a market for the bales close to their farm.
Below are a number of videos and materials to help get you started. Remember to keep an eye on this page – we’ll be keeping you up to date with everything related to the Bale Direct System.
Bale Direct financials factsheet
Sensitivity analysis – grain yield factsheet
Glenvar Bale Direct website
AHRI insight: Rules of thumb (weed seed retention at harvest)
AHRI insight: Spoiled rotten (all HWSC)
AHRI insight: To win the war you must win the battles (all HWSC)
GRDC IWM hub: managing weeds at harvest
Bale direct cost effective in the right circumstances
The Bale Direct system is an effective harvest weed seed control method that has also turned a quid for David Heinjus on his family’s mixed farm, Pareta Farms, near Freeling on the edge of the Barossa Valley, SA.
David Heinjus is well into a seven year campaign against herbicide resistant weeds using the Bale Direct technology.
Herbicide resistant ryegrass has been a challenge on their 3500 ha farm for several years and wild radish is also showing signs of developing resistance. For around 20 years oaten hay production has been part of the rotation on the farms and this has helped manage the annual ryegrass problem.
In 2007 the family leased a farm at Kapunda and reintroduced livestock to their farming operation. They are currently running 2000 ewes for wool and prime lamb production and have included a vetch and balansa clover pasture phase to the rotation of bread and durum wheat, faba bean, canola and oaten hay.
Mr Heinjus invested in the Bale Direct system in 2009, when he saw the opportunity to reliably collect weed seed at harvest and produce a salable commodity in the process.
“Livestock and hay production helped contain the problem we had with annual ryegrass but we could see that it was not going to be the whole answer,” said Mr Heinjus. “We didn’t want to burn chaff rows or heaps because our farms are surrounded by many neighbours. The Bale Direct system is a great way to collect and remove weed seed from all our crops and we have been very pleased with the results.”
To operate efficiently the Bale Direct system requires a large harvester but once the adaption is made the baling operation does not slow harvesting down. Since having the unit installed Mr Heinjus has modified it slightly, adding a small water tank and pump to spray water into the baling chamber to help maximise bale weight in hot conditions.
The bales are sold to a livestock feed pellet mill less than 10 km from the Heinjus’ farms, making the sale of 8000 plus bales a year a profitable income stream for the business. Mr Heinjus identifies availability of markets and freight as the greatest barriers to the adoption of the Bale Direct technology.
He also employs some additional casual labour at harvest time to stack the bales but overall the system has provided a good return on investment. Mr Heinjus has a professional background in financial management and planning and so was in a good position to thoroughly test the profitability as well as the practical benefit of his investment in this harvest weed seed control method.
“We have the advantage of a nearby market and we take care of the delivery ourselves,” he said. “We also sell directly to some customers who use the straw for bedding in piggeries and chicken sheds. Once the straw has been used for bedding it is generally composted and that is the final step in destroying the weed seeds.”
To maximise profitability with the Bale Direct system Mr Heinjus has kept their harvester a few years longer than he would normally keep a new harvester. He plans to sell the harvester, complete with the Bale Direct module, in 2015–16 at the conclusion of a seven-year dedicated campaign to drive down the weed seed bank.
The Direct Bale system captures over 95 per cent of weed seeds present at harvest at a cost of just under $50/ha over 1000 ha.
The only downside to the system in Mr Heinjus’ view is the continual removal of the crop residue from their paddocks. Now that the baling program has removed a significant amount of weed seed from the farms Mr Heinjus is planning to revert back to weed control methods that retain more crop residue in the paddocks.
He is confident that the hay production and livestock and pasture phase will be able to provide reliable control once the weed seed bank has been significantly run down during the seven year harvest weed seed control plan using the Bale Direct system.
“The pasture phase is a low risk break crop and weed control option for us,” he said. “We can sow vetch and balansa clover early and not be concerned about frost-prone paddocks. The high bulk pasture competes well with weeds and the sheep clean up any rogues that do appear.”
Mr Heinjus uses the ewes and lambs in a controlled grazing program to take advantage of the high bulk of feed. At weaning the ewes are removed, leaving the lambs to finish on the pasture and to clean up any weeds before they set seed.
“In addition to the weed control advantages, the pasture also provides additional soil nitrogen and is a disease break for the cereal crops,” he said. “Once the Bale Direct phase is complete we will reintroduce stubble grazing to clean up cropping paddocks after harvest.”
After some initial testing to establish that herbicide resistant weeds were present on the farms, Mr Heinjus now treats all weeds as if they were resistant and has built as much diversity as possible into his weed management plan.
“There are weeds resistant to group A and B herbicides and I expect there would be some glyphosate resistant weeds too,” he said. “We have found that we are still using similar amounts of herbicide but the sprays are more effective than they were before we started our campaign to bring crop weeds under control.”
The large bales produced have many uses in intensive agriculture, construction and energy industries, making the system economically attractive when the farm has buyers nearby.
Costing it out
Wongan Hills grower, Graham Shields, developed the Glenvar Bale Direct system, which captures all of the residue leaving the harvester, including 95 to 98 per cent of weed seeds.
Peter Newman from the AHRI communications team, said the end uses for the bales include stockfeed pellets, animal bedding, ethanol fuel and straw logs for power generation or the manufacture of strawboard.
“Overall the Bale Direct system is a great way to remove weed seeds at harvest while increasing profitability,” he said.
“However, this is a costly option if you don’t have a suitable market for the bales nearby because the system has high finance, fuel, maintenance, bale handling and residue removal costs.”
The estimated cost, based on one harvester and including nutrient removal costs for a 2 t/ha wheat crop, is $49.38 per hectare for 1000 ha, down to $32.47 per ha for 4000 ha. With access to a suitable market these costs can easily be recovered through the additional income, as David Heinjus has found.
Research supported by AHRI and the Grains Research and Development Corporation (GRDC) shows seedbanks of annual weeds can be rapidly depleted when harvest weed seed control systems are used to capture and destroy weed seeds at harvest.