A changed approach to effluent management has reduced the load for a Tasmanian dairy farm manager.
And it is providing water and nutrients that will prove valuable in filling a summer feed gap.
Mick Buckley started managing the 1000-hectare 950-cow King Island farm in March 2021.
The 100 per cent spring-calving crossbred herd is managed in a pasture-based system on the 500ha milking platform on the farm, which receives an average annual rainfall of 850 millimetres, predominantly in winter.
Mr Buckley said when he took on the farm the effluent system was based around the idea of managing a waste problem, rather than how to use it more strategically.
It was a two-pond system with a third pond for winter storage of greenwater.
Effluent water from the system was distributed around the farm via a small travelling irrigator towed behind a bike.
At that time, the first solids trap/pond was completely full and had a roughly 600mm deep sludge crust across the top of it.
Upgraded effluent system
The upgraded effluent system comprises three components:
- using a bacterial product to break down solids into a nutrient-rich water that is easier for plants or crops to absorb and which is less likely to block pumps or irrigation systems;
- recycling water from the ponds as yard wash; and
- a new mainline effluent irrigation set up, using hydrants for a hard-hose travelling irrigator that covers 70ha.
Mr Buckley said it was the best effluent system he had used is in his 13 years as a contract farm manager across five farms.
The bacterial product Efflu8 is delivered to the farm once a month in two forms: as moisture-soluble pouches and as liquid in bottles.
The 250-gram pouches contain high concentrations of anaerobic, aerobic and facultative bacteria, which are tossed into the first pond, where they breakdown and dissolve waste.
The liquid in the bottles contains high concentrations of bacteria that control odour and assist in breaking down sludge and is sprinkled around the edge of the pond.
Mr Buckley said they started using the product in December 2021 but it wasn't easy at first because of the extent of the crust on top of the pond.
They had to use a small excavator to get the product into the pond and to mix it through the water.
It took about four months for the bacteria to breed up before they started noticing the crust was reducing.
"There is no crust there anymore, it's all gone," Mr Buckley said. "And it doesn't smell as bad."
The water from the system is providing a valuable source of irrigation in the dry summer period.
The farm has some other irrigation: a 60ha pivot irrigator with access to about 200 megalitres of water stored in two linked catchment dams.
But the farm faces a feed gap in January and February.
This season Mr Buckley plans to use the effluent system water to irrigate a turnip crop to help fill that gap.
"If we can grow an extra three kilograms a day for 90 days for 900 cows that's a nice block of feed," he said.
Mr Buckley said having an effluent management system that operated seamlessly was vital.
"A lot of days, dairy farming feels like walking around with the backpack full of bricks," he said.
"Staff members are one brick, your fencing is another brick, your feeding's another brick, your milk quality is another brick, your effluent is another brick.
"That brick's gone. I don't worry about that anymore - the effluent. It's done, it's sorted.
"When we first came here, it was part of the fight essentially; now it's sorted."
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Carlene Dowie
Carlene Dowie is the editor of the Australian Dairyfarmer magazine and has more than 30 years' experience as a rural journalist.
Carlene Dowie is the editor of the Australian Dairyfarmer magazine and has more than 30 years' experience as a rural journalist.
