Mark and Andrea Hannemann
Region: Cleve, central Eyre Peninsula, South Australia
Commodity: Wheat, barley, canola, peas, vetch, fat lambs
Farming area: 1700 hectares
Annual rainfall: 400–425 mm, most of it in the growing season
Email: mahannemann@activ8.net.au
Phone: 08 8628 4036
Our two main concerns are a lack of water on our property and learning how to manage the variability of the climate going forward.
With our new water-harvesting scheme, our water security is guaranteed for the next 25 years.
See what Mark and Andrea have to say about:
- More extremes of heat, cold, storms
- Keeping the water on the hills
- Harvesting water – from 40 dams to 1 dam
- Lining and covering the dam and catchment
- Counting the cost of a purpose-built catchment
- Storing moisture in the soil to combat rainfall variability
- Keeping stock when there’s feed on hand
- Managing frost risk with different crops/varieties
- Heat stress – more to come?
- Checking forecasts on a satellite internet connection
More extremes of heat, cold, storms
Our weather patterns are definitely changing.
We get quite bad frosts and over the last couple of years they seem more severe.
And our rain events – that’s interesting in itself – we call them rain events now when we used to just call it rain.
We have catastrophic fire days now, and we’ve had some horrific bushfires here. The hot north winds are more harsh and frequent.
In 2009 we had quite rigorous thunderstorms, with a lot of hail damage. I guess they’ve always happened but they are more concentrated and have caused more damage than they did in the past.
Everything seems to be a little bit more concentrated.
Keeping the water on the hills
Our country here is very undulating, loam over clay.
Historically the farming rotation used to be 2 years of pasture/sheep and then the third year crop. During those 2 years where you had sheep running over your country, it would pack down like cement. As soon as you got a rain event it’d all run off and form gutters and cause substantial soil erosion.
Our next step was to contour all our country. The contour banks gathered the water from the gullies into the dams. And they controlled the erosion, so we didn’t get gutters forming in our paddocks.
But it was not the answer. The contours created small lands, over-sowing and inefficiencies. They also hindered the introduction of auto steer and GPS technologies.
Over the last 13 years we have adopted minimum-till practices and, with the stubble retention, we’re not getting the runoff we used to. The moisture is staying in the improved soil profile. We direct drill straight into last year’s stubble.
Adopting minimum-till practices has enabled us to grow good crops on less rainfall, because of improved soil moisture retention.
We find we don’t need the contour banks anymore because we’re keeping the water up on the side of the hills where it should be. So we’ve taken them all out.
Historically we’ve relied on 40 dams on the property for our water as we have no available mains water connection. We relied on those dams for our stock, our garden water and for spraying our crops.
But we can’t rely on them anymore for stock. We’re just not getting the water into the dams.
Over the last 3 or 4 years we’ve had some fairly dry years and we couldn’t rely on any of the dams. When summer came and we really needed the water, they were usually just full of mud in the bottom, which also created a hazard to the stock as they came in and tried to drink.
Our house dam has been there 100 years and it’s only ever been empty 4 times. And 3 of those were in about the last 5 years.
Is that climate change or the way we are farming now? A bit of both, possibly.
Harvesting water – from 40 dams to 1 dam
We are on the far western end of the River Murray pipe system, which is already an over-allocated and depleted water source and is in very poor health. We felt we had little chance of securing an SA Water supply connection to our area.
The Eyre Peninsula is a huge area and we think it’s up to us as individual farmers to be self sufficient and create our own renewable, reliable and sustainable water supply.
We were carting water from 14 kilometres in a little truck all summer for stock. It was time consuming and expensive. We thought the best way forward was for us to be self sufficient.
We have now developed a water-harvesting scheme which is, hopefully, going to satisfy our water needs for stock, for spraying and for domestic use.
We selected a site which is the highest point on our farm and we had some major earthworks done to prepare the catchment area, which is 80 X 40 metres.
The catchment area gravitates down into a 3-metre deep holding dam which is 30 X 30 metres.
Both the catchment and the dam are lined with 1-mm high-density polyethylene plastic.
It’s 98% efficient in catching water. For every millimetre of rain, we collect a litre of water per square metre. Even with a heavy dew, we’re collecting water.
On our average rainfall, which is a bit over 400 mm a year, we should get 1.6 million litres of water, which is enough to run our property for a year.
We’d probably be ok with even 300 mm. We’re still going to get 1.2 million litres of water because we’re not losing any through evaporation and soakage.
From the dam, water gravitates down to the house and throughout the entire property. On the way, we’ve got feeder troughs going off into every paddock. We’ve got a tank at the house into which we collect and use water for spraying, for our domestic use, for gardens, and for stock.
From the house, we feed water to another block, which already had poly pipes on it. We just had to put troughs on them. Now our whole farm is fed by these feeder troughs.
So this one dam has the potential to service our whole property, whereas before we were using 40 open dams.
We’re hoping that this is going to be the end of our water-shortage problems.
Lining and covering the catchment and dam
The catchment area has to be lined if you want to get close to 100% runoff.
The 1-mm polyethylene is reasonably stiff. We had to get FABTECH from Adelaide to weld it onsite. There’s $50,000 worth of plastic invested in the catchment and dam area.
The reason we lined the dam is mainly for quality of water and to minimise soakage. We use the water for spraying so we don’t want suspended clay particles in it. We don’t use it for drinking water, but the quality would be up to doing that if we wanted to.
When the dam was full we installed a floating cover on the top at a cost of $10,000. That cut our evaporation losses by 100% making it a hugely efficient system.
The 40 old dams lose 2 metres of water through evaporation each year, coupled with soakage and seepage loss.
With the cover now on the dam, the quality has improved even more. When you keep the sunlight off, you get no algae. And there’s no chemical seepage into it. It’s good quality water. Better than what we had before.
If it sounds exciting, it looks really ordinary. It’s a lot of black plastic and tyres!
Counting the cost of a purpose-built catchment
Carting water was costing us about $11,000 a year.
And it’s really unsustainable to cart water in a truck up a hill on a 30-km round trip. It was leaving a huge environmental footprint. We hated that. It was very inefficient and very time consuming.
This harvesting scheme is going to cost us about $100,000 so the payback period is 10 years. We feel we can’t afford not to do it.
Our water security is good for the next 25 years; that’s how long the plastic lasts.
Because the water scheme is based on gravitation, there are no pumps involved. No working parts. It’s minimal maintenance. You go to a paddock and switch a trough on if you’ve got sheep in there. It’s so simple.
Storing moisture in the soil to combat rainfall variability
Along with water availability, learning how to manage the variability of the climate going forward is a major concern for us. Historically, the property’s rainfall can vary from 220 mm to 720 mm.
The last 6 years have been pretty ordinary.
In 2006 and 2007 it just stopped raining from about the middle of August. Things were looking quite good or average until August but we didn’t get a finish at all. 2009 was a little bit better finish. So we have to learn how to manage the variation. Accurate long-term seasonal forecasts will certainly help with the decision-making process.
We would like to go into the area of further improving our soil and improving our soil carbon.
For every percent that you increase your soil carbon, per square metre, you can hold an extra 8 litres of water. That stored moisture is productivity and profitability. It’s also sustainability. So that’s something that we’d like to work on. Although to increase your soil carbon by 1% is really hard. So we’ve just got to take it a step at a time.
Keeping stock when there’s feed on hand
Stock are a great opportunist tool we use here.
This year [2010], for example, we had a 3.5-inch rain event in March and we sowed some feed on that and the sheep are doing terrific now. We’ve got plenty of feed and we actually brought some more sheep in. So we’ll be dropping more cross-bred lambs and hopefully we can feed them off through our stubbles later this year.
We do hay when the season’s good. If we have a lot of feed, we’ll cut that down for hay and store it. We also store oats and barley seed for feed. We just do it year by year as to what the year’s looking like.
We haven’t used our feedlot much yet but we’re hoping to get more and more into that if we get caught short on feed.
We’d feedlot sheep if we got the opportunity, if we’ve got hay on hand.
We’ve a good supply of feed now because the price of feed’s down so we’ve kept a lot of feed over. So our sheep numbers are up at the present moment because with the early opening rain we brought more sheep in. We know we can carry them, even if we have to lock them up later on and feedlot them.
Managing frost risk with different crops/varieties
Frost is a major issue, but it’s pretty hard to plan to. Different crops are flowering at different times and it depends on when you get hit.
Our crops do hang on here a little longer. We’d be 3 or 4 degrees colder through here on average than 10 or 20 kilometres away, so we’re always starting harvest a couple of weeks later than everyone else.
Whether that’s a good or bad thing, it’s just a matter of timing with frost.
We do use different varieties that flower at different times. That lessens your risk.
Of our 2 wheats, one’s a bit longer growing season, the other one is a bit shorter. So if one gets hit the other is spared. It’s like a hedge.
Canola’s the same. We’ve had canola varieties with different growing seasons and one variety did get hit with frost, while the other one got through because it wasn’t flowering.
So I guess that’s how we manage frost, and that’s about the best we can do. Because even if they forecast a frost there’s nothing you can do about it.
Years ago we were still seeding in early July because we had to wait for weeds to germinate and then deal with the weeds by cultivation. So crops were later and not generally flowering during the peak frost period.
Nowadays we’ve got chemical and we’re getting our crop planted in the optimum time. So I think there’s a bigger window for frost to occur because of that reason. The crops are flowering right at that peak time for frost.
Heat stress – more to come?
Our hot north winds are getting more severe. Our crops were heat stressed two years in a row in September on Grand Final day. It knocked everybody’s yield around.
We need better varieties to cope with the climate that we are in. If we had varieties that could withstand heat stress, that’d be terrific because I guess we’re going to have more of that.
Checking forecasts on a satellite internet connection
We rely on the internet a lot now for our information to run our business so it’s really important.
But we get satellite and it’s not that fast, so the websites that we go to are the ones with low graphics.
WX Maps is very visual but it loads up easily and that is important out here. It just has a map of Australia and you can see the weather coming in… the next 4 days with a colour coding of the rainfall that you’re expected to get.
We also look at the Bureau of Meteorology seasonal outlook and the 4-day forecast for spraying, the Elders weather site, and occasionally Water and the Land.
We need accurate forecasting, long term and short term. We need a seasonal forecast. But it needs to be accurate.
We rely on the seasonal forecasts, mainly at start of seeding.
A few years ago we just about did our complete seeding dry, and that worked out well. We dealt with the weed issues later on, which was good but fairly expensive. In this country if you leave it late it can get too wet, and if you’re well into the middle of July with your seeding program you have a fair yield penalty by leaving it that late. So we have made the decisions with the help of forecasts to go in early. We just have to deal with the weed issues later on.
Application of nitrogen is another thing we use forecasts for. If you want a rain event to wash some urea in, you’ve certainly got to rely on the forecasts for that.
For this year they’re saying we’ll have a wet spring, so that gives us a plan. It leans towards opportunity of increasing inputs and hopefully increasing our yield, our productivity and our profitability – the end point. All of those decisions are so important to our business.
With better forecasts you can move forward with more confidence, with some of your decisions.
If you knew it was going to be a dry finish you wouldn’t put so many input costs out, because you’re not going to get the yield, you’re not going to get the money return, and you don’t want screenings. So you pare everything back.
So, accurate forecasts are really, really important to the viability of our business.
Interview date: 16 June 2010
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