Bill Gordon: Ok we're looking at a multi-step, multi-tier boom here, sometimes known as a jewel boom and basically this system operates like having two or three single booms to change between each other. You'll notice in the foreground here there's 2 nozzle bodies, and the way this system operators is it'll run the first novel typically a smaller one after a certain speed and then it will change to the second nozzle, and then when you get up to a particular speed it will operate both.

The advantage of this particular system is it'll actually allow you to have a much greater speed range than a standard boom which would have just single nozzles on it. Typically one of these nozzles by itself on a boom would only give you 5 to 8 km/h, with this you can get up to maybe 10 to 15 depending on the voluem you're choosing. For guys in sandhills or undulating countries or lots of areas where they slow down that can be really good. Now these two particular novels, the one in front and one at the rear are low-pressure air inductions, which means they have a minimum pressure requirement probably about 2 bar or 13 psi in the old speak, so we need to be able to ensure that we have enough pressure running in these particular nozzles to get them to operate quickly.

That presents a bit of a challenge for the guys that operate them because one you gotta work out when to switch them or you determine the transition between this one to this one, but also when you're operating in your comfortable speed and operating volume you want to make sure when they are running together the pressure is not too low and you need to select nozzle types that don't get to coarse or the droplet size too large for what you're trying to do down here, so this particular system is very versatile but it requires the operator think just a little bit more about the speed and volume they're setting at and make sure that the pressure on these is not running too low, particularly that 2 to 3 bar, ideally you'd run these particular nozzles at 3 to 4 bar somewhere around there.

Bill Gordon: When considering what sort of sprayer you actually need, if we start with the baseline or basic entry-level—a single spray line on the standard trailing rig—we can then talk about its functions and build on those when we look at other systems.

So as a starting point, we're considering the boom. This one is a 36-metre boom, and the tank size relates to the number of hectares per hour and the machine's capacity, which is a really important consideration. I'll be looking at boom stability, but also plumbing. The number of sections that this sprayer is plumbed into is really important, particularly if you're going to use auto-section control. The more sections you have, the more even the job will be, and the more chemical you’ll save in turns.

The other functions on this sprayer we should be really interested in include the tank capacity—this one has quite a large tank, 6,500 litres—so you're looking at how many hectares per load you can get out of it. If you look at your comfortable travel speeds, you can calculate hectares per hour.

Apart from tank capacity and boom width, I’m also interested in some of the control functions. This particular sprayer has proportional valves on the back, meaning I can tune the pressure in each section and return the excess to the tank. It’s a really nice feature, but not available on all sprayers. Again, it’s worth looking at what systems are available to make your machine run really well.

When we're looking at a single spray line like this—so we’re talking about just one line with standard hydraulic nozzles—whether I’m running air inductions, low-drift nozzles, or even extended-range fans in a larger size, all these nozzles will have a certain operating range in terms of pressure. That range really limits us to about a five- to eight-kilometre speed range in the paddock.

So, when you look at your farming operation, ask yourself very carefully: how big is my real speed range? Look at your maximum speed, your comfortable averages, and how much you slow down for obstacles like washouts, contour banks, or even going up and down hills. If you have a bigger speed range than that, with a single line, you’ll tend to under- or overdose, which will cost you money. In that case, it might be worth looking at a different type of spray system.

Bill Gordon: I'm here with David Gooden, a grower from Lockhart, and we're just going to have a quick chat about some of the decisions he went through when purchasing a new spray rig. So, David, with this machine, what are some of the things you considered when you were buying it, and what were some of the most important factors for you?

David Gooden: Well, the key decision was trying to buy something for the future. We wanted something with a bit of ground clearance so we could do something later in-crop. We wanted something that would give us the ability to apply high water rates, have different rates over a range of speeds, and over a range of droplet sizes, and finally, good service and backup. We wanted to make sure we had someone who was able to do that.

Bill Gordon: So the spray system that you went with on this machine, what's it fitted with?

David Gooden: It's fitted with 3TS rapid-fire recirculation. We spaced our nozzles at 25 centimeters spacing to allow better coverage. The important thing with rapid-fire recirculation is that it allows us to apply chemicals over a large spread range and with different water rates. It also allows us to recirculate our chemical before we get to the field, so we're not having to charge up the lines before we start operating, before we start a paddock.

Bill Gordon: Any other functions or features on it that, when you were weighing up your decisions, you thought, "Oh, that's a good idea, I like that"?

David Gooden: Fuel use was a consideration, overall fuel use. So the machine we've got is a two-wheel drive, direct-drive machine, automatic, so the fuel use is quite low. The consumption is low. We wanted good service and good backup, so we wanted to deal with someone who knows about the whole system and can fix the problems when they occur.

Bill Gordon: When you purchased this machine, how wide did you end up going with the boom?

David Gooden: It's a 41-meter boom, and it matches with our controlled traffic system, so in multiples of 13.5 meters. We have a little bit of overlap.

Bill Gordon: Do you think that's an important thing for other people to consider when they're buying machines, how that sort of fits into the farming system and all the other equipment?

David Gooden: Absolutely. When going to controlled traffic, matching the sprayer is an important part of matching machinery.

Bill Gordon: So with this machine, how long do you reckon you'll keep it before you change it?

David Gooden: Maybe six years, say three or four thousand hours roughly.

Bill Gordon: So it seems to me that you spent a lot of time doing research and doing a bit of homework before you actually bought this machine, David.

David Gooden: That's right, yeah. We put a lot of work into trying to come up with the system that suited our operation and our needs and requirements to make it more efficient and effective when we go out and spray.

Bill Gordon: I think the take-home message for all growers is to do your homework and a bit of research about what sort of machine is going to suit your farming system. Think about the factors, some of the things that David talked about, and obviously service, speed range, volume, and how it fits into the future—into the farming system. They're really important. So it means that the machine that suits David may not be the same machine that's suitable for your farm.

GPS systems for positioning and machine guidance are steadily being adopted in agriculture, with New South Wales farmers using this technology to reduce costs and increase crop yields. GPS systems enable modern farming techniques such as controlled traffic farming, inter-row sowing, and variable rate application of inputs like fertilisers and pesticides.

CORSnet New South Wales is a network of continuously operating reference stations (CORS) that provide the correctional data needed for accurate use of GPS and other global navigation satellite systems. This network provides a positioning framework that makes GPS systems more accurate, reliable, and easier to use.

Satellite positioning with a single GPS receiver is typically accurate to within a few metres. However, by accessing correctional data from a reference receiver, accuracy can be improved to within 2 cm.

Wagga Wagga farmer Andrew Elmer, a leading innovator in the Riverina region, has been using CORSnet New South Wales for some time.
""We mainly use the CORSnet to run our equipment, particularly our sprayer, which we use 12 months a year. We also use it on our harvester during harvest and for seeding. We do a bit of inter-row sowing, and we appreciate its high accuracy. It's simple, and since it's a base station, we don't have to maintain it. As technology advances, the network will handle those updates.""

Elmer uses a 262 receiver mounted on the sprayer, connected to a modem that runs off the CORS network. He notes, ""We plug it in each morning, and it takes two or three minutes to boot up and fix the position, and it's good for the day.""

CORS networks differ from other correction services because their corrections are based on all surrounding reference sites rather than just one. This improves accuracy, reliability, and continuity of service, reducing the burden on farmers.

Studies show that adopting improved farming techniques using GPS systems helps to reduce fuel use, minimise soil runoff, decrease fertiliser and pesticide use, and reduce overlaps. It also lessens driver fatigue, leading to better safety, higher productivity, and overall efficiency.

CORSnet New South Wales is rapidly expanding across the state to provide accurate, reliable, and easy positioning solutions to regional areas. For the latest coverage information, visit www.cnet.com.au.

Graham Betts: ""I know this is a header tyre, but it relates exactly the same to a sprayer tyre.

The tyre information is a VF 620/70 R26. The VF stands for 'very flexion,' which means the tyre can carry 40% greater load at the same pressure, or, with an increased tyre pressure, it can carry even more load.

The 620 refers to the width of the tread in millimetres. The 70 is the aspect ratio, meaning the tyre's sidewall height is 70% of the tread width. The R indicates it's a radial tyre, and 26 is the rim diameter in inches.

One more tip: with today's auto-steer systems being accurate to within 2 centimetres, it's a good idea to line up the centre of the tyres, not the outside. For instance, you might have 800mm tyres on the front and 620mm tyres on the back. In the past, aligning the outside edges was fine, but with the precision of modern auto-steer, it's critical to align the centre of the tyres for optimal performance.