Grains Murray Scholz
Good afternoon, ladies and gentlemen. I want to talk to you today about how we're using
technology and management techniques to make our farming system resilient, and how we can
manage through difficult and trying times.
So our farm is in southern New South Wales. We're about halfway between Albury and Wagga.
We're dryland grain growers. A quarter of our country is nonarable, so we run cattle on that,
because I don't like sheep, and the rest of it we continuous-crop.
My father's quite an innovative man, and he got into no-till in the late 1970s, so I've never
actually cultivated paddock in my life. So today, I could talk about a lot of things that we doing
that are making a difference, but there's two I really want to talk about-- how we're using
integrated wind management to deal with herbicide resistance, and how we're trying to maximise
the most grain we can get some from the amount of water we have.
So why is integrated weed management important? Well, herbicides have let Australian growers
develop farming systems that are actually suited to Australian environment. With herbicides,
we've been able to take up no-till. We've been able to retain our stubbles.
Our forbears brought European farming systems to Australia, and they weren't always that
successful. Cultivation, with our fragile, old, shallow soils, isn't such a wonderful thing.
Herbicides have been a great asset to Australian grain farmers. They're cheap, they're safe, and
they're effective, and because of all those reasons, we've tended to overuse them.
Herbicide resistance develops when you only use one form of weed management. Weeds are a
very clever thing. You wouldn't think so, but they adapt to whatever a farmer's doing, and so
when we're totally relying on herbicides, the weeds have adapted, and made resistant weeds.
Resistance isn't solely a problem for conventional farmers. On my Nuffield scholarship, I had the
opportunity to visit some organic growers, and that's a paddock of wheat in Denmark-- organic
wheat.
And you'll probably notice there's quite a lot of weeds in there, and they're actually perennial
thistles. They're quite deep-rooted, and being organic farmers, the only form of weed control
they were using is cultivation. These weeds have deep enough root systems that they got resistant
to cultivation.
So the moral of the story being that if you're only using one form of weed management, it's going
to fall over. And so for us, because we were early uptakers on no-till, and early people that went
into continuous cropping, we were also early victims of herbicide resistance, and so about 2000,
we actually had total crop failure from herbicide resistance.
And at the time, we were really quite stressed about it. Did it mean that we were going to have to
totally change our farming system? Were we going to have to go back to cultivation, and all the
horrible things that happened with that, or were we going to have to bring in sheep into the
system? And that just wasn't something I was really willing to consider.
But what we actually had to change was our mindset. We had the change the way we were
thinking about how we were dealing with weeds. And so the thing that really we had to do was
stop preventing weed seeds getting into the seedbank-- getting onto the ground, staying there so
that they could grow, because every weed seed that's on the ground is one more weed that I need
to kill with a herbicide.
So we've been doing things like brown manure, where we grow a legume, which is, in our case,
is lupins. We sow it quite thickly-- almost no inputs-- and then we come back in the spring, and
use glyphosate to take out everything that's growing there, and just let the whole lot rot down.
It's a costly measure, because you're getting no income from that year. But we are finding that
we're getting a lot of benefits in added nitrogen, so we're being able to grow a crop the next
following two years with a lot less nitrogen. And it's been a major way of hitting that seedbank
down, because if you can get two years of seed control-- if you prevent weed seed set for two
years continuously-- you will beat weeds.
Another tool that we've been using quite a bit of is the old-fashioned just cutting the weed
patches into hay and silage. Herbicide resistance doesn't develop over the whole paddock
instantaneously. It usually starts in a small area, and then the harvester picks up those seeds, and
spreads them.
So if we go in and minimise that spread by cutting the weeds-- and we're fortunate. We can use
that hay in our cattle operation, but we prevent the seed set, and it just keeps the overall seedbank
numbers a lot lower. I'd just like to say, that photo-- I don't normally cut an area that big, but that
was actually a frosted wheat crop last year.
Something else that's been very successful for us, and we've been using for about 10 years now,
is narrow windrow burning. We put a simple shoot on the back of our harvester, which
condenses all the residue into a narrow row. We only do this in canola, because we've got far too
much residue in wheat, and then we come back in the autumn, and we slow-burn it.
Our aim is to get that windrow to burn at 400 degrees Celsius for a minimum of 10 seconds, and
so that length of time and heat makes most seeds unviable. And if you don't believe me, there's a
photo of a row that not all of it got burnt. You can quite clearly see the amount of weeds are
coming up. You can also see further up the road, where the road did burn. There's a few small
amounts of weeds.
The thing with all of these techniques is, none of them kill 100% of seeds, and that's why farmers
traditionally have tended not to use them, because they're not 100% effective, but in
combination, using them all together with herbicides, we've been able to knock out weed seed
numbers right back, and really get on top of the problem.
So for us, not only are we looking for just things that give us weed control. We're also trying to
use agronomic best practise that, while we're trying to get maximum yield, we're also trying to
get some weed-control benefits.
So using high seeding rates when we sow, so the crop's thicker and out-competes the weeds.
Using varieties that have early vigour, so when they're seedlings, so they grow quicker so that we
get the ground covered, so they're just much harder for weeds to germinate in the shade.
We're using precision machinery that strategically places the fertilisers so the crop's got the
advantage. There's not much future in fertilising weeds. We want our fertiliser all where the crop
can get it, and it's much harder for the weeds to get.
We're using a 2-centimetre, accurate GPS system, which lets us go back. We've got 12-inch row
spacings. We can shift that over by 6 inches, or 150 millimetres each year, and plant this year's
crop between the rows of last year's crop's residue. So that's giving us the advantage of where the
weeds-- not only do they have to deal with crop competition, they're having to deal with the crop
residue.
And we're using press wheels. Press wheels give us good soil-seed contact, which, again, gives
us better germinations, which gets the crops out of the ground quicker, again, to out-compete the
weeds.
We got into variable-rate lime a few years ago, after the drought. During the drought, lime's one
of the easiest things to knock off the budget when you haven't got any money. And so we only
had a limited budget, and we wanted to make our lime go as far as we possibly could, so we
started doing pH testing, and on the right, you can see a map of a paddock that's been pH-tested.
Traditionally, in our area, you would look at putting a blanket application of two tonne of lime to
the hectare. When we mapped that paddock, you can see the red area. That paddock's a 45hectares, and the red area is about 4 hectares.
So we were able to go in-- it needed three tonne of lime to the hectare, so we went in and,
actually, we only need to put 15 tonne of lime on that paddock. So it was a major cost-saving,
and in the last three years, we've probably saved between $70,000 and $80,000 in lime savings,
while actually getting the lime where we need it most.
But the thing that really stuck out very quickly, when we started seeing all those maps, was,
guess where the weed patch was? It was that low-pH area-- that red area-- and whether it was
because the crop isn't competing as well, or the weeds are more tolerant to lower pHs, we're not
sure. But at the end of the day, with a bit of variable lime, we're actually getting more
competitive crops, more even crops, and it's much harder for the weeds.
So the message on herbicide resistance is, it is beatable. It just needs a change in strategy. It's a
bit more work. You don't go to town to buy a solution anymore. We still use lots of herbicides,
but we need to be far more strategic and farm as if there's going to never be any more new
herbicides.
The other thing I wanted to talk about is how we're trying to maximise our water-use efficiency.
And the obvious question is, what is water-use efficiency? Well, it's taking the grain yield we
get, and dividing that by the plant-available water, and measuring it in kilogrammes per
millimetre of plant-available water.
So what's plant-available water? Well, we take the rainfall that falls from the time the crop is
sown to the time it starts ripening, less the evaporation and transpiration, less run-off, plus stored
soil moisture.
And of all those things, we can deal with-- I can effect evaporation. Retaining my stubbles
prevents a revaporation. I can try and minimise run-off. So no till makes the soil more porous, so
we get more infiltration, and stubble, again, slows the run-off.
We can gain more stored soil moisture, because if we control summer weeds, but the one thing I
can't change is the amount of rainfall. And so once we realised that that was our constraint, we
realised that we needed to work-- I can change almost anything else in my business. I can bring
in more capital. I can bring in more labour. I can buy fancy machines, but I can't make it rain any
more.
So our change in management strategy was that we made to maximise the amount of grain to
maximise our profitability from the rainfall we've got, and our goal is to average 20 kilogrammes
per millimetre of plant-available water in wheat.
So conserving summer moisture-- traditionally, in southern farming systems, conserving some of
the moisture has never been done. We've tended to graze anything that grows in the crop, with
our livestock side of the farm, but we're finding that it's really making a huge impact. When
we've got that stored summer moisture, we're now no longer dependent on getting an autumn
break to be able to plant our crops.
Every crop, every variety has an optimum sowing window. If you go past that optimum sowing
window, your maximum potential yield starts dropping away, and there is nothing you can do
about it. So we now no longer need rain, and in 2013, we were actually able to plant our entire
crop on less than 10 mm of rain during the planting window, because we had that stored summer
moisture.
Because we've got summer moisture, it means we can sow our crops earlier. We can use now
longer-season varieties that tend to yield higher. Traditionally, in our area, you'd never start
sowing before ANZAC Day. Today we're looking at starting sowing from about the 5th to the
10th of April.
And for every dollar we spend on summer weed control, we're getting about $8 back, which in
my book's a pretty good return on investment. I wish the banks would do just as well.
So this is some data from the Climate app, which is an app that's partially funded by JRDC.
They've got climate data for all over Australia, and this is from my nearest weather-recording
point. And we are asking it, how often do we get 50 millimetres of rain, which is what you would
ideally like to plant your crop on during April and May, in the optimum sowing window.
And when we look at it, it says we're only getting that 34% of the time. And the really interesting
point, if you look at the bottom bar, is that it hasn't happened since 1999. So possibly, if the
autumns are getting drier, we're more and more dependent on that stored soil moisture to be able
to plant our crops in the optimum window.
This is some work from James Hunt and John Kirkegaard from CSIRO. They were the two
gentlemen that had the idea of, what would happen to our farming system if we started
controlling summer weeds?
And if you ever look at the data from Yarrawonga, and you look at the plant-available water with
no summer weed control, you're looking at 19 millimetres. With summer weed control, it's 49. 30
millimetres doesn't sound like a lot of stored soil moisture, but when you look at the difference in
yield, 2.1 to 3.6, it's quite significant.
And that's what we're finding in our district, as well. Paddocks that have got no summer weed
control in 2000 were yielding between 2, 2 and 1/2 tonnes to the hectare. The ones that had
summer weed control were yielding 4.
So what's this mean for the bottom line? With CSIRO's figures, the cost of doing that summer
weed control is about $34-- an extra return of $300, which is a profit of $270. It's extra profit. It's
almost money for nothing. And in 2012, when wheat was $250 a tonne on farm, for that $30
extra, we were getting nearly $500 extra income. That made a huge impact to our bottom line.
For a lot of people, it makes the difference of whether they're making a profit or not.
So summing up, farming systems are complex, and we're really looking for new ideas that give
us multiple benefits. We're not just chasing yield. We want to be able to get higher yields, better
water-use efficiency, and less weeds.
We are getting productivity growth. Earlier I said that our goal was to average 20 kilogrammes
per millimetre. In 2004, when we weren't doing summer weed control, our average was 12. 2012
it was 19.5. I didn't quite crack the 20. 2013 we had a frost, and it stuffed it up, but we were still
able to get 12 and 1/2 kilogrammes. And in the paddocks that weren't frost-affected, we were
able to get between 20 and 25 kilogrammes, and that was on a spring that was 75 millimetres
below average.
I think there's an urban myth out there that we farmers don't tend to change. Farmers do. We are
constantly evolving our systems, and I think when we see something that works for us, we're
quite happy to grab it, and run with it.
I think the other thing that's quite important-- and I've been quite pleased to hear it today-- is that
research is crucial. All of these things that I've implemented in my farming system have all been
ideas from researchers that researchers have then quantified, and farmers have put into practise
and qualified. And without organisations like CSIRO, JRDC that are adequately funded, I think
Australian grain production can't continue to grow, and can't continue to be resilient. Thank you.
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