When it comes to helping farmers win the battle against weeds while reducing reliance on chemicals, you might say one South Australian company is crushing it. Kangaroo Island-based Seed Terminator produces a mechanical device of the same name which pulverises weed seeds at the harvesting stage, before they get the chance to grow up and run riot among crops.
The brainchild of the company’s co-founder, farmer/inventor Dr Nick Berry, the Seed Terminator tackles a problem inherent to crop farming: the fact the harvesting process is the weed’s best friend. Because when the crop is cut, once the chaff and grain have been separated, the harvester flings the chaff back onto the ground. This includes the seeds of weeds that have escaped or resisted the various stages of herbicide spraying – in other words, the toughest customers of all. When these survivors are redistributed, the whole harvesting process has simply set farmers up for problems the following year.
‘Problems’ may be an understatement. In 2016 Australia’s Grain Research Development Council estimated that weeds cost Australian grain growers about $3.3 billion annually, and – because weeds deprive crops of sunlight, water and important nutrients - yield losses of 2.76 million tonnes. They also put the cost of herbicide resistance at $187 million a year, for herbicide treatment and other weed control practices.
Nick’s invention is a smart and cost-effective solution. The Seed Terminator is an attachment that retro-fits to most combine harvester brands, and it uses multi-stage hammer mills to pulverize weed seeds along with the chaff so they can’t sprout. What's left is a fine sawdust-like mulch that actually puts nutrients into any soil that it’s spread upon. Installed on a typical harvester, the system can distribute that mulch up to 14 metres. It’s a one stop weed killer and mulcher as well as grain harvester.
“What tillage does, by its motion, is it rips the ground open and dries out the soil. If you are in a moisture limiting scenario like most of Australia, then that reduces your yield,” says Nick. Then along came a significant change. “All of a sudden we started to get some really effective chemicals come out, like glyphosate, which facilitated a whole change in agricultural practice. We moved away from tillage altogether, particularly in Australia.”
Still the world’s most used herbicide, glyphosate saw yields go up, and a lot of area that wasn’t suitable for cropping suddenly became viable. Then come the 90s things shifted again. “After 30 years, herbicides start to become an issue,” says Nick. Repeated use of the same herbicides led to herbicide resistance. A small minority of weeds of one particular species, thanks to a slight genetic variation, would be resistant to the herbicide. Over years of using the same herbicide, these survivor weeds would flourish and eventually dominate. The herbicides needed to be used more often and in stronger doses.
So the focus shifted back to the machinery itself, with a wholesale change in harvester design. Phil Zani of Harvestair had the Rotomill Cage Mill working by 2001 but between 1995 and 2005 there was a doubling in capacity of machines and the design couldn't handle the throughput. There was a lot of investment in making these mobile factories more efficient, but the central problem remained; combine harvesters weren’t killing the weeds, merely redistributing them.
Enter Nick. The farmer’s son and mechanical engineer had been paying close attention to developments in the field, and knew there must be a better solution.
From 2010, the GRDC had stepped in, with money. They began to fund the work of farmer Ray Harrington, who had the idea of attaching to a trailer a heavy-duty mill originally designed to turn coal into briquettes but which could also crush weed seeds. But the Harrington prototype came with a few problems. First, weighing in at one tonne, the mill was a colossus. Second, it had to be trailed behind the harvester (class 9 or larger mind you). And then the biggie: the price tag. It was going to cost some $250,000 – out of reach for most farmers.
“GRDC started to put money into it, and to realise that they needed some engineering.”says Nick The GRDC had engaged a consultant, Graeme Quick, to look at the prototype of the Harrington Seed Destructor (HSD). Quick concluded it would never be accepted by the American market unless it was integrated into the harvester. He proposed that a parallel project look into an ‘integrated weed seed terminator’ – (“The name Seed Terminator is my tribute to the great man,” says Nick).
The project was to be run at the University of South Australia (UniSA) and, largely funded by grain growers’ levies through the GRDC, Nick was granted a scholarship for the work. His PhD research was to explore ways to kill weed seeds on board a harvester. This started with a prototype – which failed. Then it was back to the drawing board, looking at how much energy was needed to kill weed seeds. Then creating some computer modelling process to evaluate how to evaluate energy input into seeds in a mill.
“We’ve got farmers who are anywhere from 600ha to 20,000ha and they all run different brand harvesters and different size ones, but they all have sustainability issues with herbicides. They need an integrated approach, to be using herbicides but to protect them from resistance, and drive down the weed population with something mechanical. Our vision is to reach as many farmers as possible, as quickly as possible and as economically as possible. Affordability is really important. While we develop the tech, we also need to reinvest in making it better.
And so Nick set about developing his own machine. The first pilot Seed Terminators were introduced in 2016, and now there are some 250 machines in operation worldwide, each retailing for around $110,000.
The design is constantly being refined but essentially it’s a mechanical system that uses the harvester’s drive to transfer power to two multi stage hammer mills. These grind, shear and pulverise the chaff once it has been been separated out from the grain – ensuring even the toughest weed seeds won’t be back.
“With chemicals you have ‘pre-emergent’ herbicides, that you put down at the time of sowing,” explains Kelly Ingram, marketing director of Seed Terminator. “Then you have in-season herbicide spraying while the crop is growing. We come in at the end. We tidy up all the weeds that have been missed. Potentially they are herbicide resistant, or perhaps they grown later and managed to dodge the herbicides.”
After working closely with farmer research partners over some 296 harvests, the Seed Terminator technology is paddock proven and farmer focused, says Nick. While they’ve increased the number of weed seeds killed by the mill, that’s not the only measure of achievement. They’ve also evolved the mill technology over the past four years to drive down the cost of the wearing parts and how long they last, and to increasingly decrease the amount of power used in the process.
Seed Terminator also conducts ongoing trials in a number of universities in both Australia and overseas to test the ability to kill weeds. The University of Adelaide testing found the device able to kill 99% of notoriously tough rye grass seeds. “Seeds come in different shapes and sizes so you need to apply different amounts of energy to kill them. How we set the mill up in different parts of the world varies slightly. We also do field trials on how many seeds we can capture with the harvester.”
Explains Kelly: “We have designed our technology so it can be pretty much used anywhere. The standard technology will go out to 98% of our farmers and will work fine and the other is the high capacity for when you have tricky conditions. The standard one works well in most situations."
While the Seed Terminator is getting uptake in Europe, Canada and the USA, it’s all still a learning curve, says Nick. “We’re just trying to understand how it fits into other people’s farming systems. One of the biggest learning things is mindset differences and attitudes. Farmers in Australia are very innovative and happy to modify their machines and do something a little different in order to give them a long-term benefit. We hear words repeated like ‘I want to be able to leave my farm in a better state than I found it’. It’s a generational thing – they want to hand down the farm to their kids and grandkids.”
He believes the public perception of farmers is often skewed, but Australian farmers’ ready adoption of technology that protects the land is tangible proof of how invested they are in longevity. “To go and spend $100,000 on a Seed Terminator is amazing.”
“Farmers care deeply about their land and its ability to produce food for the world. That long-term attitude isn’t only in Australia but it is pretty unique. People come here and are gobsmacked that a farmer would spend more money on something that’s not necessarily going to deliver him a return this year but over the next four years.”
Farmers are out there, day in day out, closely observing the life cycle of the plants and the soil. “They see the issue. They see it doesn’t make any sense to spread weeds with their harvester,” says Nick. “With Seed Terminator, they are getting revenge on their weeds."
Quick to adopt new technology, farmers recognise innovation as their friend, says Kelly. “Farmers always have their finger on the pulse about the latest developments. People are coming to us; it’s farmers talking to other farmers, it’s word of mouth,” she smiles. “People are really excited about it. And it’s nice that it’s ag tech – it’s not an app. It’s a mechanical solution.”
Meanwhile, Nick sees it as Seed Terminator’s mission to stimulate change, through commitment to R&D and developing further mechanical solutions to help farmers protect their crops. “We’re not only looking at how we can smash seeds but the whole system - how can we mechanically intervene to make farming more sustainable. We want to look at this as a holistic thing.”
And from here, who knows where this journey of innovation will lead, but thank you to all grain growers who played a part thus far.
MY18 Multi-stage Hammer Mill
Mechanical Drive - 31% Less Power
We designed a mill that can handle drops in engine RPM without significantly effecting capacity or kill, which enabled us to harness the efficiency and simplicity of the mechanical drive without being tethered by fluctuations in engine rpm. Our drive is driven off the harvester’s engine with minimal moving parts, incorporating only shafts, belts and gearboxes. This is to maintain a lower power draw and fit to class 7-10 harvesters. We use precision machined custom bearing spindles and a custom, German made spiral bevel gearbox.
The War on Wear
We have attacked wear on multiple angles this year with
We created the Aero-IMPACT 2.0 system that efficiently creates high air flow for maximum capture of weed seeds, minimum disruption of the harvester sieve and minimise infeed blockages. Uniquely able to maintain high air flow under highly loaded conditions even at reduced rpm. We have optimised the residence time that material is in the mill, to improve capacity, reduce wear and reduce over processing. We have also improved the aerodynamics of our impact elements which has meant less turbulence and therefore less wasted energy.
The diagram above shows the movement of straw, chaff, grain and air in the harvester. The baffle-beater gap let's air escape unrestricted, too much air escaping above baffle = risk losing seeds. Seed Terminator's huge air flow means less air escaping above baffle = no cleaning shoe air restriction and maximum capture of weed seeds.
As you can see in the video material is sucked into Multi-Stage Hammer Mill even with the side covers off.
South Australian Grains Industry Trust funded research conducted by Trengove Consulting in 2017 found ryegrass weed seed kill was 93% at 2250 rpm and increased to 98% or greater at normal operating speeds (2500–3000 rpm). Results also showed than 99% control of several other species including wild radish, brome grass,wild oat, bifora, bedstraw and tares and increasing chaff flow rate (harvest rate) did not reduce control of these species
96% Kill Performance
The Weed Science Research Group, a part of the University of Adelaide confirmed that Seed Terminator could consistently reduce germination of Annual Ryegrass by 96% compared to a control sample.
Associate Professor Chris Preston, Geoff Philips, Dr Nick Berry, Associate Professor Gurjeet Gill, PhD Candidate David Brunton, Graduate engineer Keagan Grant
[ August 2018 ]
After a few late nights fitting up the Seed Terminator, Nick spent two weeks operating the harvester, trying different Seed Terminator configurations, different harvesters setups, measuring grain loss, living and breathing harvest. There are a huge number of design changes for the MY2018 Seed Terminators. If it is one thing we have learnt, it is that what works in theory and what works in the field can be miles apart. There is nothing like proof in the paddock; being able to test the machine in Canada prior to our Aussie harvest is a great opportunity to get a jump start on 2018 lessons. Header (nee Combine) Uptime is a big focus for us, the most important thing we can do is not interrupt your harvest operation. We have already implemented a few tweaks to the design based on the early results in the field.
We are gathering information on how to operate our new blockage sensors and a bushel of knowledge (excuse the pun) on how to drive the machine. One of the things we had to deal with in the early Canadian harvest was an abundance of green weeds at harvest, mostly Kochia; driving to conditions the Seed Terminator 'ate her greens' without a fuss. Others include high harvest moisture (15-18% Canola, 20% Wheat, 18% Peas), cold temperatures (haven't had a day above 20 degrees yet), moist conditions including harvesting during drizzling rain and working through tough canola straw, so far she hasn't missed a beat!
AeroIMPACT 2.0 = Capacity, capacity, capacity
Early reports confirm the new AeroIMPACT 2.0 technology is able to replicate the increased capacity we saw in the lab, in the paddock; bring on Harvest 2018!
A Kangaroo Island purpose built facility will provide direct access to farmland, harvest machinery and collection of crop materials, while combining science, engineering, feedback in a confidential space enabling us to create next generation technology.
"The indications so far are that the major cause of wear is any soil that reaches the mill. When harvesting crops with the front right on the ground or if the ground is undulating, soil can enter the harvester fronts. For high silica soil types wear rates are highest. Outer screens are the first component to wear (because of maximum material speed). The middle and inner screens last proportionally longer (reduced tip speeds) than outer screens. Rotor and flails are similar to middle screen life. We have learnt that there is another compromise that needs our focus; cutting height to capture weeds and wear rates because of soil entering the front." Nick Berry
First set of tests in January 2018 show that 15-20% power reduction is looking very achievable within our current design framework.
[ October 2017 ]
The South Australian Grains Industry Trust is using one of the three test stands to trial the Seed Terminator against a range of crops including Wheat, Canola, Lentils, Beans, Chaff laced with Ryegrass, Broom Grass, Turnip, Prickly Lettuce, Medic, Tares, Wild Radish, Bifora, Bedstraw, Marshmallow and Wild Oats. Early results show Seed Terminator is over performing.
July 2017 Image above is of one of the three test stands: Pitot tube with hot wire anemometer to measure the air flow, torque transducer to measure torque, dustpan and broom to measure kill!
During 2017 harvest there were many learnings and on balance, it was a successful one and a massive leap forward from 2016. The Seed Terminator's beat the living daylights out of billions of weed seeds across the country; 32 machines running successfully across 4 Australian states. Our Farmer Research Partners not only made a real difference to the sustainability of their farms, but they have played a huge part in developing our technology to assist the whole industry.
Our upgraded drive system worked really well, farmers noted that they didn’t notice power draw in canola and barley if the conditions were good. Long green canola straw presented an issue in some areas, if at times too much straw ended up in the mill hoppers. Harvester setup has a role in this, for example an internal chopper on a CASE machine throws straw better than an internal beater. We were able to implement a blockage sensor on one machine which proved quite effective. As the season progressed and the crops dried out, blockage issues disappeared. In the wheat and lupins, engine load was increased over barley and canola. Cutting wheat low to the ground to collect weeds requires a lot of power to thresh. Additionally, wheat produces a lot of chaff on the sieve and can contain a lot of short straw for the mill to process. 35 tonne/hour of wheat produces around 10 tonne/hour of chaff. Lupin pods on the other hand are just tough to process! Our farmers did note that the material coming out of the mill was highly pulverised and volunteer and weed seeds exiting the mill were like flour. This amount of pulverising ensures that there are no escapees in tougher conditions when the moisture is up, or the seeds are smaller, however it comes at a cost of additional load. Lesson 1 from harvest was that there is an opportunity to reduce the amount of pulverisation and the load on harvester.
In the middle stages of harvest, we started to notice that some machines had more mill wear than expected, particularly in sandy soil types. Low cut heights and undulating ground can result in sand entering the harvester and into the mill. Also rain can splash sand onto the lower part of the plant. This effect is so profound that we found nearby farmers cutting the 7-10cm height have twice as much wear as 15-20cm height. Clearly there is another compromise between cut height (and collection of seeds) and mill wear. On some machines, sand also gets sucked through the harvester fan, particularly machines with tracks.
"I have been asked, if the sand is entering the harvester then why isn’t my harvester wearing out? And the answer is all around tip speed. Nothing on the harvester has any where near the tip speed of the rotor which is around 330 km/h. At these speeds sand acts like a sandblaster, biting into the steel."
Lesson 2 from harvest was we need a resistant wear package for sandy regions. At harvest we managed to trial 3 different surface treating options with some good success but a lot to work on.
The harvest finished up and the team went straight to work on reducing power and increasing wear life. A lot of brain storming, some fundamental modelling, and lots (and lots) of prototype testing. In addition to these goals we have continued to develop our drive system. One season of testing is not enough to test long term reliability, so we are using accelerated life testing of components in the off season.