Getting water when and where it’s needed has had a transformative impact on the Vallance family farm at Nirranda.
A variable rate irrigation system installed about three years ago has been the key to success, allowing the farmers to make the most of their water entitlement and to concentrate resources where they’re needed.
The family is mindful of the need to look after water, biodiversity and soil and to reduce their waste and emissions.
The farm was purchased in 1995 by Bruce and Andrea Vallance. They now run it as an equity partnership with farm manager Isaac Fynn and their three children: Jordy, Sam and Casey.
Sam and Casey work off-farm, and Jordy worked as a vet for a number of years before transitioning back to the farm full-time two years ago.
“I enjoy that farming can have a positive influence on the environment,” she said.
“There are exciting things happening in agriculture looking at how we will farm in a changing climate. I was lucky to have two careers that I really enjoyed but I’ve always loved the farm.”
Bruce and Andrea are still active in the business but are looking to reduce their involvement. Isaac is responsible for the day-to-day running of the farm, while Jordy, who has oversight of long-term strategy for the business, works alongside Isaac and oversees animal health.
They milk 830 cows on a 287-hectare irrigated milking platform that allows a high stocking rate with a split calving system and three-way cross of Friesian, Montbéliarde and Swiss Red.
About 140ha under permanent irrigation and 36ha are irrigated for a few weeks at the end of the season and in autumn if needed to utilise the farm’s water entitlement.
“When we bought the farm, we started with a small entitlement for pumped groundwater, but as we purchased blocks around us, some of them came with water as well so that increased our entitlement,” Bruce said.
The farm now has a 708-megalitre entitlement, a benefit that is common in the area and one of the factors making Nirranda such prime dairying country.
They have five centre pivots watering varying areas to make up the 140ha, and 36ha of fixed-point sprays.
Remote technologies used to run the system ensure they get the best results.
“We have soil moisture probes that are linked by two-way radio back to the dairy that tell us when to start watering,” Bruce said.
“You can look on the screen at the different pivots and see where your moisture levels are sitting. They are linked so you can run them off your phone.
“It will send a text message is there’s a fault and there’s an app so you can adjust the speed settings or move it to another spot.
“It is a better use of resources and time.”
The Variable Rate Irrigation (VRI) system is particularly helpful but this technology has not been previously adapted in the region because iron bacteria in the water blocks the fine sprinkler heads and valves.
Jordy says new water conditioning technology uses resonance frequencies to disrupt bonds between minerals and charged compounds that result in mineral solids being dissolved so the iron bacteria is able to pass through without blocking.
To set up the VRI, an EM (electromagnetic) 38 survey is used to map soil types, elevation, drains and topography.
“It is mapped on the computer and then transferred to the pivot box which has a watering map so the sandy areas will get more, wheel tracks and wet areas will get either none or less,” Bruce said.
“There’s a lot of data and scientific evidence about where you should set the rates. It’s really good for our farm because we’ve got a lot of variation in soil type.”
The system also ensures that cow tracks running through the irrigation don’t get any water and areas around drinking troughs are kept dry.
“If we get a heavy rainfall event during summer, you can wait for your swampier areas to dry out,” Bruce added.
“You have different maps for different parts of the year. When you start irrigating, all of your wet areas get very little water. The sandy areas drain faster so they get more to start with.”
Jordy says the VRI system allows them to deliver the water requirement that the grass needs for optimal growth, not more or less.
“It increases our efficiency by optimising the pasture growth and allows us to use our water allocation as effectively as possible, and it decreases our electricity costs because we are watering where we need it,” she said.
Bruce estimates the water savings over the past three years at between 10 and 20 per cent, with a similar saving on electricity.
“It makes our water entitlement go further and it has dried up the wetter areas so we’re getting better growth in those areas because they’re not flooded.
“This is backed by recent studies that have shown up to 20 per cent reduction in water use and a 0.5 tonnes DM/ha increase in pasture production.”
Jordy adds that in traditionally dry areas, pastures are persisting better and living through summer.
“We’re better able to manage the areas that we know get waterlogged through spring. Those areas are performing better because they’re not getting the same allocation as the drier areas, which means we’re growing more and buying in less feed.”
After a trial from 2020-22, the farm is now dedicating four to 10 hectares a year to multispecies pastures.
Bruce said the results so far have been positive.
“I was fairly sceptical when we started about what the benefits would be but they seem to be stacking up,” he said.
“We’re starting to see what is possible with multispecies and there are more gains to be had so we will continue with them and wait and see about animal benefits.”
Jordy said the paddock used for the initial trial was sandy and had trouble establishing pasture.
“Multispecies are working well for our farm,” she said.
“With multispecies, we’ve been able to get a perennial base in that paddock. The persistence of the pasture is great. It’s giving us feed at a time of year when the rye-grass, which is the majority of the farm, is slower.”
The measures have been introduced for sustainability, but with an eye on the bottom line.
“We’re a commercial dairy farm and we’ve been able to integrate these sustainability measures into our business,” Jordy said.
“Every strategy has to be able to stand alone, be profitable and has the added benefit of leaving the land in better condition.
“Sustainable farming practices are worth investing in to help future-proof dairy”
During November the Vallance family hosted a multispecies pasture, water efficiency and revegetation field day presented by Warrnambool Coastcare Landcare Network as part of the Building Climate Resilience and Increasing Productivity and Biodiversity on South West Farms project.