Glenarty Road
Case Study: On Farm Composting, Lower Blackwood Catchment
About Glenarty Road
Glenarty Road Farm has been in the McDonald family for five generations. Originally part of the Group Settlement Scheme, the area was cleared (the Group Settlement Scheme required farmers to clear 5 acres of virgin bushland per year in order to continue to lease farms until land rights were granted) and the family folllowed a traditional subsistence agriculture model - cows for milk and cream, whey fed to pigs for food and veggies grown in a loamy soil backyard, until in the 1960s Peter McDonald took over the farm and transformed it for sheep.
Peter's son Ben had a flair for agriculture and went on to study viticulture. In 1997 (at age 19) he single handedly planted the family vineyard, but he was always a sheep farmer at heart so continued Peter's legacy by establishing Margaret River Grass-Fed Lamb. He also continued to enhance the biodiversity of the farm.
Ben and Sasha McDonald
Ben and Sasha McDonald
The Cellar Door evolved and officially opened in July 2017 after converting the original 1950s farm workshop.
The restaurant opened in December 2017.
The farm now grows:
- 10 varieties of grapes (26 acres under vine - Semillon, Sauvignon Blanc, Chardonnay, Voignier, Muscat, Shiraz, Savagnin, Vermentino, Fiano, Pinot Noir and Malbec
- 16 varieties of hops
- Vegetable gardens
- 1300 wool shedding sheep (Ultrawhite and Sheepmaster)
- Square Meater Cattle + Chianinas
- A family of pigs
- 250+ fruit trees (including macadamias)
Farm Fact File
Farm Size: 240 acres
Location: Karridale, Western Australia, 3 hours south of Perth with the coast about 15kms to the south and the west
Soil Type: loam
Climate: Mediterranean.
Wettest month - July (long term average mean 181.2mm )
Hottest month - December (monthly mean 25.5 degrees)
"It is our vision to sustainably farm fresh produce, make creative wines that are an honest reflection of our land and encourage people to share, enjoy and celebrate life." - Ben McDonald
Composting Experience
Up until this year Ben has only done small scale composting for the vegetable gardens.
The compost was held in three bays made of wooden pallets, which were managed so that there was always one compost bay that was ready to be used, one new one, and one partially ready.
Contents for the compost included cow manure, chicken manure, all green waste, straw, veggie tops, corn husks - or whatever was being used on the farm that the pigs weren't eating.
Ben had made the soil for the veggie gardens from scratch - one third compost, one third red clay and one third lime sand, where the lime sand was used to get the PH right for the root vegetables to penetrate (and the carrots didn't end up being little turbine looking things!)
But Ben was keen to go bigger. He realised that he had materials on the farm that could be used as compost, so he wanted to find a way to go beyond the veggie patches and see how compost could be beneficial to the vineyards and fruit trees.
Farm scale composting project
Recently Ben slashed a local subdivision. When he was finished, the area didn't make the fire requirements for the rangers because there was still three years' worth of dead grass on the ground, so Ben offered to remove it.
He cut, rolled and baled the old grass. Although it couldn't be used as feed, he hoped it could be used as part of a composting project.
He also purchased 125 tonnes of cow manure, which he added to the grass rolls when they were on site in his paddocks (he was careful to only do this after the summer heat to avoid the risk of spontaneous combustion in the warmer temperatures.)
The pile is about 15 meters wide, 70 meters long and 3 or 4 meters high.
Ben's compost pile: heavy chunks of matted straw and dried grasses are hard to mix.
Ben's compost pile: heavy chunks of matted straw and dried grasses are hard to mix.
The goal was to use this compost on the vines and fruit trees, but unfortunately Ben realised that there were a few ways he could have managed his raw materials better...
Challenges:
Ben's pile of material was just too big to handle easily. It needed to be mixed, but doing anything by hand was almost impossible due to the scale of the material. When he had initially built the windrows he laid out the hay rolls out then put the cow manure over the top, but these materials are heavy and dense, so quickly became impossible to combine. Ben will have to use machinery to mix it which may be problematic due to potential bogging on the site or even the instability of the pile.
"We'll have to use the Caterpillar Telehandler which can pickup two or three tonnes at a time and just try to throw it to the other side and slowly turn it lengthwise. If it's too boggy I'll have to wait till summer...but I hope I can make some kind of impact before that."
The size of the pile also meant that even after rainfall, the middle of the material was still very dry.
Ben is confident that the material will eventually become a usable compost, but due to the size and unmixed composition, it is likely to take a lot longer than originally expected.
Additives:
Eucalyptus is often in the grasses and greens locally, and Ben has noticed that it can make the compost hydrophobic. He plans to add red clay to counter this.
Instead of burning or burying his livestock, Ben plans to add them to the compost pile so that any energy that is grown on the farm stays on the farm.
He may also receive abalone waste from the local fish factory. They have offered 20 tonnes of abalone parts - which will be beneficial for digesting the straw of the pile.
What would he do differently next time?
Reduce the size of the compost pile:
The recommended size for compost windrows depends on how you are planning to mix it. Keep it low enough to be stable, and narrow enough for the tractor to be able to empty materials right to the centre. Any bigger and the pile is unmanageable; sections can't be reached by either hand or machine.
Shape of the pile:
Ideally, windrows are lower and flatter. With the more pyramidal shape (as Ben's have) rain slides down the sides rather than filtering into the material.
A lower, flatter shape is easier to handle, mix and use.
A lower, flatter shape is easier to handle, mix and use.
Even at scale, narrower, lower windrows are more practical. At some farms a mechanical mixer can run over these smaller rows, so the materials can be mixed. But when the piles are so high, the machine just can't track over them.
Compost mixer at Willyung Farms in Oyster Harbour
Compost mixer at Willyung Farms in Oyster Harbour
Mixing the layers:
Ben admits that he should have mixed the materials better. The big chunks of hay and straw are heavy and hard to handle.
"I should have spread the hay out with a hay cart then done a layer of grass and more straw, then the cow manure on top of that."
Find better quality materials:
The manure that Ben sourced had a high percentage of soil, which will impact the speed of the material decomposition.
Ben's Advice
Equipment
A good front loader and spreader could make all the difference. Having the right machinery for larger compost piles makes the process quicker and easier.
Locations
Concentrate on your key areas. It works really well for vegetables and super high input areas- (Ben will focus on his vineyards) - so avoid trying to spread what limited compost you have over broadacre areas.
Resources
Use materials that are cheap and easy to get hold of. Build partnerships with other farmers - chicken farmers could supply sawdust or chicken manure. Seaweed could be an option. The local council may be able to offer woodchips from roadside collections.
On Farm Composting Workshop
On Farm Composting Workshop
Glenarty Road hosted a one-day on farm composting workshop in June 2023. This gave Ben some pointers on how to improve his composting program.
David Hardwick of Soil Land Food led a step-by-step composting demonstration, which highlighted some of the key elements of creating a successful fermentation compost.
Fermentation Compost
Fermentation Compost is a low cost and easy method for effectively composting at a large or small scale.
Instead of turning the compost regularly to add air (aeration), the compost pile is inoculated with specialised fermenting microbes then covered and left to decompose without turning.
A successful fermented compost will be a stable product with a dark brown colour indicating a high level of humus with no weed seeds or pathogens.
Future Plans
After pruning under the vines all the sticks are swept into the middle of the row. These are chipped so they don't get tangled in the nets. The Glenarty Road plan is to pile it all up under the vies so every second row is a green manure crop and every other row will have the prunings in it. These will be slashed, thrown into the compost and piled up under the vines to try to suppress the weeds and stop competition under vines. Ideally, this will also help the vines retain moisture too...
Ben will focus most of the compost on his vines and vegetable plots, but will use the remainder on the paddocks at a rate of 100 tonnes of compost per hectare.
"I'm still on the hunt for enough biomass to make the compost volumes I need. Our fertiliser budget used to be about $20,000 a year for synthetic fertiliser. I'm going to spend every cent of that in cow manure and other materials that I can use to make our own compost and organic fertilisers instead of on synthetic fertilisers." - Ben McDonald
This case study was produced by 'Talkin' After Hours', the Lower Blackwood Landcare's Online Community & Information Hub
The case study forms part of a collaborative roadshow that took place across seven catchments in the south west of WA in June 2023 to encourage farmers and landholders to build their knowledge and skills to make and use compost.
The roadshow was coordinated by the Lower Blackwood LCDC in collaboration with the other catchment groups , and funded through Soil Wise. Soil Wise is funded by the National Landcare Program Smart Farms Small Grants – an Australian Government initiative. It is supported by Healthy Estuaries WA – a State Government program.
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