Get all your news in one place.
100’s of premium titles.
One app.
Start reading
ABC News
ABC News
National
Lara Smit

Dairy farmer uses multi-species, legumes and charcoal to combat climate change

David Vonhoff runs a dairy farm in Queensland's Darling Downs region with more than 200 cows. (Photo: Lara Smit)

Summer arrives sooner and the hot, dry winds linger longer than when David Vonhoff was a child helping his parents on the farm.

"What is it going to be like when my grandson gets to my age?" he says.

In the Darling Downs region of Queensland, Vonhoff runs a 1500-acre farm with more than 200 cows, producing some 1.3 million litres of milk per year.

Vonhoff, 67, bought the farm 38 years ago and he has seen the climate change dramatically since his childhood days on the family farm.

"The spring and summer have been coming on a lot sooner," he says.

"The temperatures are getting a lot higher and with the drought in 2019 we just got very large amounts of hot, dry winds. In the past we never used to get that sort of situation, just a couple of days of it." 

Vonhoff doesn't think climate change is solely to blame but he thinks it has exacerbated the situation. 

Now he has adapted to benefit his business and reduce the footprint he leaves on the planet. 

Vonhoff says that his cows, mainly the Australian Illawarra breed, benefit massively from all the trees he has planted. (Photo: Lara Smit)

Planting trees for cow-comfort

Over the past years, Vonhoff has planted more than 20,000 trees on his property.

The trees surrounding his paddocks bring advantages, he says.

During hot summers, his cattle can be found resting in the shade under the trees.  If those trees had not been there, the cows would be under a lot of stress, which influences milk production. 

"Because of cow-comfort it's estimated that cows can produce two litres of milk a day extra," he says. "So that can be worth an extra $56,000 a year to us." 

Vonhoff says he has planted more than 20,000 trees on his property, which he says is beneficial for "cow comfort" and milk production. (Photo: Lara Smit)

Multi-species and legumes

As he walks through one of his paddocks where high flowery plants and legumes are growing, these multi-species with a variety of plant roots feed the soil micro-organisms, which enhances soil carbon and overall soil health. It reduces water logging in the ground and it serves as feed for livestock.

By planting the multi-species Vonhoff does not need to use any nitrogen fertiliser.

Nitrogen fertiliser is used to provide crops with the nutrients they need to grow, but also emits greenhouse gasses as it is being used, according to the Climate Portal from the Massachusetts Institute of Technology.

Vonhoff has planted legumes and multi-species to benefit his cows and the environment. (Photo: Lara Smit)

Professor Susanne Schmidt, environmental scientist and educator at the University of Queensland explains why legumes are a good move.

"Those legumes turn nitrogen in the atmosphere into bioavailable nitrogen, which is the nitrogen that plants use for growth. So if you have a legume-rich pasture, the nitrogen gets regenerated.

"So the legumes use nitrogen and also provide protein-rich food for the animals to grow fast and develop well," she says.

Schmidt also explains that adding the multi-species and legumes to his pastures is a type of regenerative farming.

"Regenerative means you're not relying on fertiliser inputs, but as much as possible on the natural ecosystem," she says. 

Adding charcoal to cow feed

Vonhoff also volunteers his cows to participate in scientific research working to find ways to reduce methane emissions.

An assessment from the United Nations Environment Programme (UNEP) concluded in 2021 that cutting farming-related methane emissions would be pivotal in combating climate change.

About 32 per cent of human-caused methane emissions comes from livestock. Methane is a very powerful gas, over a period of 20 years it is about 80 times the warming power of carbon dioxide, UNEP states.

Methane takes only about a decade to break down, as opposed to carbon dioxide which can take many centuries. That means that reducing methane emissions has a relatively direct effect on the climate.

A study that Vonhoff participated in, looked at ways to reduce methane emissions from livestock. It was conducted by Dr Les Bowtell, who is senior lecturer at the School of Engineering at the University of Southern Queensland.

In this study Bowtell researched whether adding half a per cent of powdered activated carbon into the pellets fed to Vonhoff's cows, made a difference in the amount of methane they emitted.

Vonhoff's cows, pictured here grazing in multi-species, were fed activated charcoal over the course of 12 months. (Photo: Lara Smit)

Activated carbon, also known as activated charcoal, is a black, odourless powder that has been used for centuries to treat different aches, like poisoning.

It is made by burning any organic material with a high carbon content, so that could be wood,
coconuts or nutshells.

"The gold standard at the moment to produce activated carbon, is from coconut shell, but we can also make carbon from different types of waste like macadamia nutshell or from the tops of sugar cane," Bowtell says.

Almost any source of biomass waste, like plants or animal products, can be used to make viable activated carbon, which brings another benefit with it. 

"You can capture the energy as you go, so you could get around one kilowatt hour of electricity or nine megajoules of heat per kilogram of bio-waste, as well as getting activated carbon," Bowtell says.

The study aiming at lowering methane emissions was conducted over a 12-month period and showed a 30 to 40 per cent reduction in methane emissions from the cows.

"I think the solution to climate change, ironically, might be carbon," Bowtell says.

'It's scary'

Vonhoff tries to be optimistic.

"You can identify opportunities. You really need to be studying the situation and identify how to turn a negative into a positive."

Schmidt agrees on the importance of these opportunities. "By doing things in a clever way, the farmer has to do less, intervene less. They are doing it because they understand the system." 

"...There are people around that are really passionate, but there are people about that are so entrenched in the old traditional ways of doing things. It's sad and disappointing to see farmers with that type of thinking, but it's even more so to have politicians inclined the same way," Vonhoff says.

Still Vonhoff knows that people can change their mind, looking back at his own climate action journey.

He has had a lot of discussions and conversations with his neighbour, cattle farmer Sid Plant, who has been getting involved in climate action since the late 60s.

Sid Plant, cattle farmer (left), and David Vonhoff have shared a lot of climate change knowledge with each other. (Photo: Lara Smit)

"I could have had more knowledge and understanding in the beginning. I may have been a bit more traditional back then," says Vonhoff, when looking back.

Vonhoff's passion about 'climate destruction', as he calls it, makes him think and worry of the future often.

"What we're experiencing now is only the beginning. What's it going to be like when my grandson gets to my age and things are going to become even more extreme? What we're seeing now is just going to get worse, and you know, it's scary."

Sign up to read this article
Read news from 100’s of titles, curated specifically for you.
Already a member? Sign in here
Related Stories
Top stories on inkl right now
Our Picks
Fourteen days free
Download the app
One app. One membership.
100+ trusted global sources.