GRANT Evans and Andrew Jenkins are among the many Western Australian dairy farmers improving their effluent management systems.
They are seeing savings on fertiliser and water with help from a program aimed at improving the health of the state’s waterways.
The Evans farm at Jindong, WA, near Busselton, has seen gradual infrastructure upgrades in recent years, including to pond systems, irrigation systems and most recently a new dairy shed and solids pad.
“We did an upgrade five years ago, when Western Dairy funded dairy farmers up to a certain amount of money, to try to get everyone up to the Code of Practice,” Mr Evans said.
“We installed a new solids pond and expanded the use of a travelling irrigator, which now has enough range to access better soil types for irrigating effluent. The application rates and timing are all calculated out in our effluent plan.
“I think the biggest thing was getting an effluent sample tested and seeing what the nutrient concentrations were. It’s clearly a waste if you don’t use it.
“Also using the solids and liquids to build the nutrient profile on the paddocks lowers your fertiliser bill, so you save money on that.”
And the savings add up. An average WA 500-cow herd can produce more than $10,000 worth of fertiliser (nitrogen, phosphorus and potassium nutrients annually).
Mr Evans is regularly updating the farm’s effluent management plan as other infrastructure and systems on the farm evolve.
“We built this new dairy shed recently and had to update our effluent management plan,” he said.
“We installed a flood-wash system with re-used effluent water. Luckily, we already had our two-pond system and the effluent irrigation set up.
“The idea is that over winter your pond needs to hold all the effluent from the dairy shed. Before these upgrades, the system was at its capacity for our number of cows.
“Our most recent upgrade has been the solids pad through Healthy Estuaries WA.”
Western Dairy’s extension officer Dan Parnell has been on hand to support farmers like Mr Evans, enabled by funding from the State Government’s $25 million Healthy Estuaries WA program.
Previously called Regional Estuaries Initiative, the program has helped more than 1600 dairy, beef and sheep grazing farms since its inception.
“Dan is the man for the dairy farmers,” Mr Evans said.
Updated Code of Practice launched
Mr Parnell said Western Dairy worked with farmers, catchment groups and the Department of Water and Environmental Regulation to update WA’s industry Code of Practice for Dairy Farm Effluent Management, which was launched in 2021.
“Now we’re working alongside farmers to continue helping them get their effluent systems up to code,” he said.
“We use the Code of Practice as our go-to document, intended to make sure dairy effluent systems catch and reuse nutrients on farm. With increasing herd sizes, we catch more effluent and need a larger system and more land area to reapply those nutrients.
“Initial investments from farmers and the state government tackled some of the more significant infrastructure upgrades that farmers needed.”
The funding through the DairyCare project (the predecessor to the current Dairy for Healthy Estuaries project) provided $845,000 for effluent system upgrades across 21 farms.
“When we do effluent system reviews with farmers, we can see how they’ve made strides towards meeting the code,” Mr Parnell said.
“Our priority is helping them implement their effluent plans, address remaining gaps, and keep systems maintained and working properly.”
Three-pond design installed
Western Dairy chair Andrew Jenkins is a dairy farmer at Denmark on WA’s south coast and has similarly invested in systems that allow him to reuse effluent to grow pasture.
“In 2019, we jumped on board with the funding that was available at the time, and with the help of Dan from Western Dairy, we came up with the design for a three-pond system,” Mr Jenkins said.
“The effluent is recycled from the third pond to wash the yard – that’s been really good at saving us water.
“There is 1.6 kilometres of mainline pipe running out to the back of the farm where 40 hectares of the farm receives effluent irrigation.
“Any solids that are collected are composted in windrows and spread out away from the dairy shed.”
Protecting downstream waterways
Niamh Rayne is the Dairy for Healthy Estuaries project officer at the Department of Water and Environmental Regulation, and a recent import from working in New Zealand’s dairy industry.
Ms Rayne said best-practice effluent management helped protect downstream waterways and benefited farmers.
“WA’s dairies are located in the south-west corner of the state, where many of the soils are sandy and prone to nutrient loss,” she said.
“Effluent management is one of the most important ways to minimise nutrient loss from dairy farms.
“Downstream waterways like our estuaries are under pressure from excess nutrients washing in from the catchment. These nutrients can cause harmful algal growth and conditions that occasionally kill fi sh and other aquatic life.
“Since joining the Dairy for Healthy Estuaries project it’s been really encouraging to see how farmers are committed to working with us and keeping nutrients on their farms as much as possible through the way they manage their effluent, as well as other actions like fertilising based on soil test results.”
The Dairy for Healthy Estuaries project not only provides a $740,000 investment from the WA State Government for Western Dairy’s extension work with farmers, but is also making things happen behind the scenes to enable best practice.
“We are working to bring multiple stakeholders along on this journey, including local governments, who also need to understand how effluent management works in order to do their part in the planning process of dairy shed upgrades and new builds,” Ms Rayne said.
“Recently we visited the Evans and Jenkins farms with local government planning and environmental health officers. They came away from the day better prepared for future development applications from dairy farms.
“Every farm is different, and the effluent system design needs to be considered in the context of the business and the local climate and soils.
Our hope is that getting out on farm and providing resources that complement the Code of Practice will better support farmers through the planning process when they’re looking at upgrading infrastructure.”
Mr Parnell said some emerging shifts in the WA dairy industry would make best practice effluent management even more critical.
