Gavin Lerch's family property was once planted with sugar cane. Today it thrives as a 7-year-old macadamia orchard on tough grey-clay soil.
The farm faces shallow topsoil and the routine loss of organic matter during harvest. To meet these challenges, Gavin turned to compost. It feeds soil microbes, improves water retention, and strengthens tree health.
Working with Oreco Group, Gavin creates custom blends of wood chips, manure, and macadamia by-products. Every shell, husk, and kernel return to the paddock, cycling nutrients back into the soil. The results have been striking and show the long-term value of compost.
Watch how Gavin turned poor clay soil into a thriving, sustainable farm built to last for generations.
Transcript
[Music plays and an image appears of an aerial view of rows of macadamia trees as the camera zooms across the trees]
Gavin: We have limited topsoil on this property.
[Image changes to show a farm laneway with sheds and tractors, cattle looking at the camera, various views of macadamia trees, and then the inside of a tractor cabin with Gavin driving]
We need to increase the organic matter, to improve the soil, to make the trees more resilient, and to fight off the diseases that they face and be able to produce as many macadamias as we can.
[Music plays as image changes to show fingers caressing a macadamia flower, and text appears: Compost in Macadamia Farming]
[Image changes to show Gavin talking to the camera, and text appears: Gavin Lerch, Macadamia Grower]
My name is Gavin Lerch. Our family farm is on the north side of Bundaberg.
[Image changes to show a tractor mowing the grass beneath the macadamia trees]
Farming is in my blood.
[Image changes to show the inside of a tractor cabin with Gavin driving, and then the image changes to show a photo of Gavin as a child looking at the camera holding a hammer above macadamia nuts]
I've got a photo upstairs, I was cracking a macadamia nut when I was 18 months old with a hammer.
[Image changes to show an aerial view of rows of macadamia trees as the camera pans in]
73 years ago, my grandfather bought this property to produce sugar cane.
[Images move through to show a medium and a close view of Gavin talking to the camera, and then a close views of Gavin smiling while having a cuppa looking over the macadamia trees]
Our profitability was just not there for sugar cane so we decided to make the switch to macadamias with the view of a long term profitable crop.
[Music plays as image changes to show a close view of macadamia tree branches]
[Image changes to show Gavin talking to the camera, and then the image changes to show a view looking up to a forest canopy]
Macadamia is a native in the rainforests around Queensland.
[Images move through to show leaf litter on the forest floor, tree trunks and ferns in a forest and then a close view of a macadamia flower]
The mass of leaf matter and compost under the big tall trees and these native macadamias are in there thriving.
[Image changes to show a close view of Gavin talking to the camera, and then the image changes to show a medium view of Gavin talking to the camera]
So we're trying to build a soil with lots of organic matter because that's what the trees expect.
[Images move through to show macadamia trees, views of Gavin scooping up compost handfuls, views of Gavin talking to the camera, Gavin with a colleague, and hands picking up macadamias]
Compost includes lots of important nutrients, but there's a diverse biology in compost that feeds the microbes, improves the soil health, improves the drainage within that soil, and ultimately increases the productivity of the tree.
[Image changes to show an aerial view of the rows of macadamia trees as the camera pans down]
This farm's got marginal soil.
[Image changes to show a photo of a tractor ploughing, and then the image changes to show another photo of a tractor ploughing]
It is a grey clay, a very shallow top soil and a heavy clay down deep.
[Images move through to show views of Gavin talking to the camera, an aerial view of the rows of macadamia trees, cattle looking at the camera, a compost pile, and then a photo of tilled ground]
So in 2017 we started preparing this land and even before the trees were planted, we were banding manure and compost up each row to ensure once we form the rows and the compost and that organic matter was deep down in the soil, that the trees would be able to feed from that for many years into the future.
[Music plays as image changes to show a rear view of Gavin looking out over the macadamia trees]
[Image changes to show a close view of macadamia branches as the camera pans down, and then the image changes to show a close view of Gavin talking to the camera]
One of the great benefits of compost is that organic matter.
[Image changes to show a medium view of Gavin talking to the camera, and then the image changes to show Gavin's hands using a shovel in the compost pile]
The more organic matter in the soil, the better and the higher water retention we have.
[Image changes to show a tractor driving towards the camera between rows of macadamia trees]
It improves and promotes root growth.
[Image changes to show Gavin listening to a colleague while looking at a macadamia tree, and the image changes to show another view of Gavin and the colleague talking together looking at the tree]
Our farming system requires us to sweep and to blow the mulch out from under the tree during the harvest time.
[Image changes to show a rear view of Gavin using a shovel in a compost pile]
Anything that we remove, our goal is to replace that organic matter.
[Music plays as image changes to show Gavin's hand holding compost as it trickles through his fingers]
[Image changes to show Gavin talking to the camera, and then the image changes to show Gavin's hands opening a macadamia nut while he's holding a bowl of the nuts to his chest]
So from our farm, we send the nut and the husk away for sorting and processing.
[Image shows Gavin's hand placing the macadamia shell into the bowl and then the camera zooms out showing Gavin eating the macadamia nut]
And there's shell and husk that is a by-product of the process.
[Images move through to show piles of compost, an aerial view of Oreco and the compost piles as the camera pans left, and then an aerial view of the compost piles as the camera zooms in]
We rely on our compost supplier, Oreco, to provide a consistent, reliable product.
[Music plays as images move through to show a front end loader, a close view of macadamia shells, a Pronar machine milling compost, and then a front end loader collecting compost]
Oreco have been very keen to take the by-product of the macadamia husk and waste and turn that into a very valuable compost.
[Image changes to show a close view of the loader's bucket moving left off screen revealing Gavin and a colleague looking at the compost pile, and then views of Gavin talking to the camera]
We have been using a wood chip based compost for several years, but it's great now to have access to the macadamia by-product from the processing plant so that the husk and the shell and the kernel can go back to the paddock where it came from.
[Images move through to show a medium and then a wide view of Gavin eating macadamias, and then an aerial view of the rows of macadamia trees as the camera pans up]
As farmers, we're doing our best to conserve or protect our greatest asset, which is our soil.
[Music plays as image changes to show a medium view of Gavin talking to the camera, Image changes to show a close view of Gavin talking to the camera]
Now that the harvest season has finished, most people are pruning and applying compost.
[Image changes to show Gavin talking and walking towards the camera with a colleague beside a compost pile, and the image changes to show Gavin and the colleague getting handfuls of compost]
I've also received a fresh load of compost from our supplier today.
[Image shows the Gavin and the colleague talking, and the camera zooms in on their hands holding the compost, and then the image changes to show Gavin talking to the camera]
They're adding some manure, adding some wood chip and sawdust and making a custom compost blend for us.
[Image changes to show Gavin and the colleague watching the Pronar machine adding to a compost pile, and then the camera zooms in on their hands as they scoop up handfuls of compost]
They give us the option to ask for whatever products we'd like to add.
[Image changes to show Gavin scooping handfuls of compost and letting it trickle through his fingers]
So if there's limes or gypsum or anything that we'd like to put into that, they're happy to work with us.
[Image changes to show Gavin talking to the camera, and then the image changes to show a tractor mower mowing under the macadamia trees as the camera pans left]
So all of the nutrients that we've removed, we're bringing some of that back into the farm with the compost, and the kernel and the shell that is part of that compost.
[Image changes to show and then a rear view of the tractor mowing between the macadamia tree rows, and the image changes to show a front view of the tractor mowing between the tree rows]
We add some other manures, we can customise a compost blend to exactly what we need on the farm.
[Image changes to show Gavin talking to the camera]
So yeah that's good news for the trees.
[Image changes to show a colleague and listening to Gavin talking as he's picking up macadamia nuts, and then the camera zooms in on Gavin's hands cracking open macadamia nuts]
There's multiple outputs from macadamia production.
[Image changes to show Gavin and the colleague inspecting the macadamia nuts]
There's lots of other by-products that are used.
[Image changes to show a medium view of Gavin talking to the camera, and then the image changes to show a close view of Gavin talking to the camera]
One of the local sugar mills uses macadamia shell as part of their fuel source.
[Image changes to show the camera zooming along a farm road past trees, tractors, equipment and sheds]
We work closely with our local agronomist.
[Images move through to show the camera zooming between macadamia tree rows, macadamia tree branches, views of Gavin talking to the camera, and then Gavin reviewing reports documents]
They'll take our soil and our leaf tests, it's an important way that we can get a snapshot of what we're dealing with and then adjusting our nutrient plan accordingly.
[Image changes to show a close view of the business report graphs documents in Gavin's hands]
So each year we spread compost under the trees.
[Image changes to show Gavin talking to the camera]
It's no secret that many of the corporate farms around this district are using large amounts of compost.
[Images move through to show views of Gavin using an iPad, Gavin's hands holding report documents, and then Gavin with a colleague inspecting at macadamia nuts]
It's easy to look to the one season ahead and the input costs for that compost.
[Camera zooms in on Gavin and the colleague as they inspect a macadamia nut]
But the benefits of compost really pay back in more than just that one season.
[Image changes to show a medium view of Gavin talking to the camera, and then the image changes to show a close view of Gavin talking to the camera]
Um, there's multiple years that the compost and the tree health is going to benefit.
[Music plays as image changes to show a tractor driving towards the camera between macadamia tree rows]
[Images move through to show sunlight filtering through macadamia tree branches, and then a medium then a close view of Gavin talking to the camera]
We are already seeing a trend of increasing our organic matter from the results of our soil tests.
[Images move through to show an aerial view of macadamia tree rows, a close view of macadamia tree branches, and then Gavin and a colleague checking over a macadamia tree]
Our trees are about seven years old and we basically doubled our crop from last season.
[Image changes to show Gavin smiling down at report documents in his hands, Gavin's hands using an iPad to scroll through a macadamia photo report, Gavin's hands cracking open a macadamia nut]
And I'm confident with the compost that we applied last year and the season before that we're starting to see that true benefit.
[Music plays as image changes to show Gavin holding a bowl of macadamia nuts while he's eating a macadamia nut]
[Image changes to show macadamia tree rows with Gavin's hands holding a cupper in the foreground, and then the image changes to show Gavin talking to the camera]
We're trying to have a sustainable farming operation for future generations, and compost is such an important part of that process.
[Music plays as image changes to show Gavin smiling at the camera]
[Image changes to show a green screen with the Australian Government Coat of Arms, and text appears: Department of Climate Change, Energy, the Environment and Water]
