PADTHAWAY, SOUTH-EAST SOUTH AUSTRALIA
Commodity: Grapes, small-seed crops, sheep, lambs, beans, wheat, canola
Farm area: 800 hectares
Rainfall: 450-550 mm per year
In 2008 the water table dropped significantly. For several years, we had much lower rainfall than we were used to. It rained, but not enough to replenish the aquifer. Because of this, we had to reduce our pumping rate. If we were going to continue to have dry years, it was important for us to upgrade our surface irrigation system to a surge irrigation system. We needed to ensure we were making the very best use of the water available.
My husband Bradley’s parents started on this property about 45 years ago and we’ve been here, running the farm with them, for more than 25 years. One of our daughters, Casey, has just returned to the farm and is keen to learn about the farm and the business.
We have recently bought our neighbours’ property – 300 hectares of cropping, irrigation and pasture – which is keeping Casey and Bradley busy setting it up like the rest of our property.
This involves improving the irrigation channels and bays, along with making many other improvements to bring it up to a production and efficiency level we are happy with. There is a lot of work to be done.
We have vineyards, broadacre cropping (wheat, canola, barley and beans), small seeds (lucerne, phalaris and clover) and livestock (sheep and lambs).
Mixed farming means we can change our enterprises to suit how weather and prices are going. That’s the beauty of living in this region: you move with what’s growing best and making the best returns.
We can increase the number of paddocks we plant if cropping is going well, or increase our stock numbers if cropping is not so good. It gives us a bit of flexibility. And having irrigation gives us a certain level of protection against low-rainfall years.
But mixed farming can be difficult because each enterprise has got its busy time of the year – having a mixed system makes us extra busy. But that’s okay – you learn to manage that and juggle everything into some sort of balance.
Some people you talk to about climate change ridicule it and say it’s not happening. It’s a personal choice whether you believe it is or isn’t: we still have to deal with the variability.
Extremes of temperature are our main concern here, especially when the crops are flowering. Mostly, it’s frost in the spring and heatwaves in summer.
Frost can destroy the new season’s shoots and flowers on our vines and crops.
We have put in sprinklers to protect our vines from frost. They turn on when the air temperature reaches 2°C or 3°C. The sprinklers rotate around the vineyard and the spray stops frost settling on the vines.
Frost sprinklers are quite a big investment, but more and more people are going that way. They’ve worked for us.
In terms of our broadacre and small-seeds cropping, random frosts can be a disadvantage at the end of the season during flowering. To manage this risk, we sow a couple of different varieties of wheat or barley that flower at different times.
Heatwaves shut down vine growth and can ‘sunburn’ the berries. Crops literally cook when there’s a heatwave – the grain can smell like it’s been toasted.
The last few summers we’ve had several days over 40 °C but this year [2014/15] we’ve only had three. It’s definitely been a milder summer.
When we hear that researchers are trialling drought-resistant or frost-tolerant varieties, that’s exciting for us. It helps us manage what we can’t control.
We haven’t had decent spring rains for a long time now.
Last year  we didn’t have any rain after July. This affects our whole operation, particularly our crops and pastures.
Even though we didn’t get any rain during spring last year, we still managed to harvest a reasonable crop. We put that down to having reasonable rain early in the season, which helped fill our soil profile and establish our crops early on.
We’ve been fortunate that, in the last few years, we’ve had rain over summer and autumn, as this has allowed us to sow earlier.
The advantage of sowing early is the crops will get up and away quicker in warmer soils, and be well and truly established before it gets really cold.
In terms of our grapes, we don’t necessarily want summer rain; we prefer to control the moisture they receive using drippers. From December to March, we are stressing our grapes leading up to harvest to ensure we get the best berry development and flavours.
Summer rains also increase the chance of fungus and disease. In 2010, we had a lot of summer rainfall and, as a result, our vines were infected with botrytis and downy mildew [both are fungi].
We tried to prune the grapes that were infected, but as soon as we had finished a row, the ‘unaffected’ grapes were already showing signs of disease. We lost over half our crop that year.
There was nothing we could have done about it. The vines had all the right chemicals; it was one of those seasons with record summer rainfall and the perfect climatic conditions for disease. We hope we never have to deal with that again.
In Padthaway, we have an underground water supply. The water runs like creeks and rivers through limestone, below the soil surface and at varying depths.
We drill boreholes down to where one of these creeks and rivers crosses, so we can tap into the largest flows. We use surface irrigation on the small seeds, and drip irrigation in the vineyard.
In 2008 the water table dropped significantly. For several years, we had had much lower rainfall than we were used to. It rained, but not enough to replenish the aquifer.
Because of this, we had to reduce our pumping rate. We were putting out 500 kilolitres per hour through our pumps and, in two years, that suddenly dropped back to 160 kilolitres per hour.
So we had to look at the best way to use the water we could extract.
We had a study done by the South East Natural Resources Management Board. We discovered the best option was to improve what we were already doing, upgrading the surface irrigation system to a surge irrigation system and increasing our channel holding area.
[Surge irrigation is a type of furrow irrigation. Water is supplied on and off at planned times: e.g. on for 1 hour, and off for 1.5 hours. The wetting and drying cycles slow how fast the water soaks in, which means it can travel faster and more uniformly.]
We used to pump the water into the channel and, if the gate was open, the water would go straight into the hectare-sized bay. It was taking about 10 hours to water a bay, which was an inefficient use of diesel and power.
With the surge irrigation system, we can now water a bay in an hour, so there’s less pumping time. There’s also less time for the water to evaporate.
We fill up the channel. Once it’s full, the first automatic gate opens into a bay. A bay is roughly 500 metres long and 100 metres wide. When the water reaches a set point, the gate shuts again, and then the next bay opens.
Over the years, we have been able to identify exactly how long each bay takes to water, so there is no waste. It is a very precise system. We keep very good records from year to year.
Each bay has its own check bank [a raised-earth border] to keep the water contained. It doesn’t ‘wild flood’, which is what some people think surface irrigating is. It’s all very controlled and very efficiently done.
What we’ve worked on over the last 5 years [2010-15] is calibrating the system so we get as much water as we can over the paddock in the least amount of time. That way, we can be sure the whole paddock is uniformly watered and we get a more uniform crop.
This helps reduce waterlogging of the plants and soil, and reduce the risk of evaporation. We have very shallow soils over limestone, so what the plant doesn’t use drains back into the aquifer – good for the water resource and the plant.
At the moment we’re aiming to use 1 megalitre per hectare. We would like to get it under that, and plan on testing it in the future to see if we get the same yields.
If we were going to continue to have dry years, it was important for us to upgrade our surface irrigation system to a surge irrigation system. We needed to ensure we were making the very best use of the water available.
It’s been a huge undertaking, we have invested a lot of capital into the upgrade. But it’s been a huge success: we have seen improvements that we never thought could happen.
We have renewed enthusiasm for irrigation, and the challenge of continuing to improve our water-use efficiency is ongoing.
South Australia’s south-east is officially classed as a high-rainfall zone. We used to have plenty of rain here, but we haven’t seen that for a long time – 10 years or so.
This means we have to work on keeping what moisture we can.
One way we’re increasing our water efficiency in the irrigated areas is with better plant management.
We are spraying to remove the perennial plants between rows to allow the water to flow through quicker. Before, the thick grass used to hold up the irrigation water.
We’ve also compacted the base of our irrigation channel to reduce seepage. So, again, that’s saving water.
We used to have a 10-day rotation watering the phalaris. After 10 days, we’d start the pumps again. Now we’re using more soil-moisture monitoring equipment, and sometimes it’ll be every 6 days we need to water, and sometimes it can be out to 12. We’re listening more to what the plant’s telling us.
Our yields in 2010 were 200 kilograms per hectare above what they generally are, and above the district average too, which is really nice. Bradley puts it down to the plant roots not being waterlogged so much.
All our bays are laser-levelled and have a bit of a fall [gradual slope] on them, so the water drains off quickly.
We also look at different methods of planting to retain our stubble. We’re trying to retain more and more stubble every year to save moisture. But retaining stubbles brings its own issues in this region.
Snails and resistant weed seeds are a huge problem; burning seems to be a key factor in dealing with these issues.
We have several fixed soil-moisture probes throughout the vineyard, each with rain gauges attached. The probes measure soil-moisture retention at 3 different soil depths: 20, 40 and 60 centimetres.
The probes are all connected by wi-fi so we can view the data in real time using an iPad at home, to see if we should be watering the vines or not.
We still need to go out and have a look, though. You can look at screens all the time but you really need to go and touch to feel the heat in the vine leaf during the day. If the leaf is very hot, the vine is not hydrated enough.
When there’s a heatwave coming, we need to make sure we have water all the way down to 60 centimetres so that the vines will be able to withstand the heat.
We try to keep water that deep during the season, but dry out the [soil] profile before our grape harvest to stress the grapes – it helps with flavour and colour.
It’s difficult trying to reduce moisture to that level quickly in our vineyards without splitting our berries. When you’re stressing the vines, they are likely to suck up any water you give them and channel it straight to the berries.
To overcome this, we use drip irrigation and a ‘pulse’ watering method. You water continuously for 4 to 5 hours, turn it off for a few hours, then turn it back on for another 4 to 5 hours. This drives the moisture down the profile.
In the broadacre and irrigation systems, we are currently using G-Dots, which measure plant-available water at 30 centimetres deep. We find them very helpful. You can drive past in the ute and have a quick look at where things are at – and make decisions based on the information they provide.
Keeping accurate records of events and readings throughout the irrigating season is one of the most important things we do.
We record every irrigation event, pumping rate, rainfall, and anything else that can have an effect on our outcomes.
It has proved very useful; the data helps us to build up a baseline of knowledge that we use in future years to make decisions.
We compare our eventual yields with what happened through the year. This is simple, but it works for us.
We’re always looking at new ways to manage our enterprises, and seeing how other people do it so we can implement similar changes here if they are suitable.
Even if you pick up one new way to manage frost from someone else, for example, it’s worth it because that one thing could make a huge difference.
I’m also the Chief Executive Officer for a grower group in the south-east called the MacKillop Farm Management Group. It covers farmers from Keith in the upper south-east, to Millicent and western Victoria in the lower south-east.
We coordinate research, development and extension in the region and act as a portal for researchers and other bodies to get new and relevant information out to farmers and agribusiness. We focus on trials of new varieties, agronomy issues, and new and innovative ways of farming.
It’s also a great network for making contacts and sharing ideas. A lot more of our members are using social media to share information, too, which is great.
Interview dates: 17 May 2010, 30 January 2015
Krysteen McElroy on her property in Padthaway
The McElroy’s vineyard
The McElroys would prefer it doesn’t rain between December and March, before they harvest their grapes
Under surge irrigation, the McElroys pump groundwater into their channel…
… until it is full, then…
… automatic gates open and close at pre-determined intervals to water each bay
Bays are roughly 500 metres long, 100 metres wide and have a gradual slope. When a channel gate opens, water runs from the channel (in the foreground) into the bay, and moves down the bay
The McElroys have compacted the base of their irrigation channel to reduce seepage
Bradley McElroy viewing the soil-moisture profile of his vineyards from his iPad
Krysteen and Bradley McElroy on their property in Padthaway, South Australia