Modern Australian
Men's Weekly

.

Biochar doesn’t just store carbon – it stores water and boosts farmers’ drought resilience

  • Written by Sirjana Adhikari, Associate Research Fellow in Mineral Processing, Deakin University
Biochar doesn’t just store carbon – it stores water and boosts farmers’ drought resilience

As the climate changes, large parts of southern Australia are projected to get drier. Extreme rains are also becoming more common.

For farmers, these changes pose big risks. What can we do to manage changes already locked in? One adaptation is ensuring water soaks into spongy soils rather than evaporates or runs off into waterways.

This is where biochar comes in. You might be familiar with the use of this charcoal-like substance to store more carbon in soil. But biochar has another very useful property: it’s often highly porous. If you add it to soils, it can store water from rain or irrigation until plants draw it out. It can also help unlock soil nutrients and restore soils degraded from overuse.

This year, biochar experts released a farmers’ guide covering how to use biochar to boost drought resilience, maximise crop yields and increase disease resistance.

But how do you make it sustainably and at scale? Our new research has found one answer – use green waste from our gardens and also mix it with other suitable sources.

coriander seedlings and biochar
Biochar’s water storage abilities can make a big difference for crops. Sirjana Adhikari, Author provided (no reuse)

What’s so good about biochar?

Biochar looks like traditional charcoal. But charcoal comes from wood and is used for fuel. Demand for charcoal drives deforestation in some countries.

Biochar can be made from everything from food waste to wastewater biosolids, to forestry waste or agricultural waste such as wheat straw and nut shells. It’s made by heating organic matter in low oxygen, a process called pyrolysis.

Pyrolysis typically produces more energy than it uses, meaning biochar manufacturing can also produce bioenergy. Pyrolysis has far lower carbon emissions than if the waste was incinerated or left to decompose in landfill.

Biochar came to global notice as a promising way to combat climate change. In 2018 it was recognised for the first time as a possible negative emissions technology.

This is because the biochar process locks up its existing carbon and adds to it by increasing soil carbon. If scaled up, biochar could store substantial amounts of carbon which cannot be lost to wildfires or microbial breakdown.

But biochar has another key benefit: it can store a surprisingly large volume of water. A single kilo of biochar can store up to 4 litres of water.

biochar Biochar looks like charcoal - but it’s made for a different purpose. Gulthara/Shutterstock

When rain falls or when farmers irrigate, biochar-improved soil holds water for longer. In sandy soils where water drains quickly, biochar can hold it for more than ten days and slowly release it as crop roots need moisture.

When we add good quality biochar to soil, we make soil more porous. This provides space to hold water, for soil microbes to colonise, and for air to circulate. In turn, this improves access to soil nutrients for plants.

What are the downsides? At present, we don’t know enough about whether pyrolysis removes all chemicals of concern, or if some risks outweigh the benefits over the long-term. So-called “forever chemicals” may not be completely destroyed by pyrolysis. And if pyrolysis is not designed properly, toxic dioxins can form.

In some circumstances, biochar could nudge soil microbes to produce chemicals that are not beneficial. Biochar could also add salts, trace metals or other toxins to the soil if contaminated organic waste is used.

These issues can largely be avoided with careful design of biochar engineering processes and testing.

charcoal Burning organic matter in low oxygen environments produces biochar. Sirjana Adhikari, Author provided (no reuse)

Different feedstocks materials?, different biochar

Earlier this year, we published research confirming good quality biochar stores carbon for hundreds of years.

The choice of raw materials for biochar makes a big difference. When manufacturers used woody materials, we found the biochar was highly stable. But biochar from biosolids (solids derived from wastewater) was less stable.

A particularly good type of biochar is made from wood, branches and grasses. This biochar boosts access to potassium and calcium in loamy or sandy soils, tackles salty soils and gives plants better access to nitrogen. Using biochar doesn’t mean you stop using fertilisers – but it can help farmers get more out of soil additives. It also has a very high water-holding capacity of up to 60% of its volume.

Using certified biochar is a good way to ensure you’re getting a high quality product.

If used well, biochar has real promise. Our new life cycle assessment found by spreading around 58 million tonnes of biochar on our farms would remove the equivalent greenhouse gas emissions of every Australian household (68 million as of 2017) for a year.

Perfecting biochar

There are ways to optimise how we make biochar. For instance, aging biochar for a year enables it to hold more water.

Different particle sizes suit different soils. Recent research shows fine-grained biochar works best for clay soils, while coarser biochar is best for sandy soils.

charcoal under microscope Different feedstocks produce different types of biochar. On the left is garden waste biochar and on the right is biosolids biochar. Sirjana Adhikari, Author provided (no reuse)

Biochar availability and use is growing. The global market next year is forecast to reach almost A$5 billion. Larger biochar production facilities can maximise the benefits of the heat energy released, and also control any risky emissions. But you can make biochar in your garden with a simple setup.

There’s work to do figuring out the best biochar, soil and microbe interactions for plants, and adding biochar to broader sustainable farming practices.

The world is full of good ideas that don’t get traction. What makes biochar more likely to succeed is the fact it can work for farmers and for the planet.

Read more: Here's how to fix Australia's approach to soil carbon credits so they really count towards our climate goals

Authors: Sirjana Adhikari, Associate Research Fellow in Mineral Processing, Deakin University

Read more https://theconversation.com/biochar-doesnt-just-store-carbon-it-stores-water-and-boosts-farmers-drought-resilience-235765

7 Common Air Conditioner Issues in Melbourne – And How to Fix Them

Image by freepik Living in Melbourne, we all know how unpredictable the weather can be. One moment it’s cold and windy, the next it’s a scorchin...

Powering Palm QLD with Reliable Electrical Solutions

Image by pvproductions on Freepik When it comes to finding a trustworthy electrician Palm QLD locals can count on, the team at East Coast Sparkies s...

The Smart Way to Grow Online: SEO Management Sydney Businesses Can Rely On

If you’re a Sydney-based business owner, you already know the digital space is crowded. But with the right strategy, you don’t need to shout the...

What Your Car Says About You: The Personality Behind the Vehicle

You can tell a lot about someone by the car they drive—or at least, that’s what people think. True Blue Mobile Mechanics reckon the car says a l...

The Confidence Curve: Why Boudoir Photography Is the Empowerment Trend You Didn’t Know You Needed

Boudoir photography has been quietly taking over social feeds, Pinterest boards, and personal milestones—and for good reason. It’s not just abou...

Understanding Level 2 Electricians: Why Sydney Residents Need Licenced Experts for Complex Electrical Work

When it comes to electrical work around the home or business, not all electricians are created equal. In Sydney, particularly when you're dealing wi...

Retirement Anchored in Model Boat Building for Waterford’s Doug Unsold

WATERFORD — When Doug Unsold sees his ship come in, it’s usually one he’s crafted with his own hands. The 67-year-old retiree from Waterford ...

The Science Behind Alarm Clocks and Your Circadian Rhythm

Waking up on time isn’t just about setting an alarm—it’s about working with your body, not against it. At the heart of every restful night and...

How to Use Plants to Create a Calming Atmosphere in Your Home

In today’s fast-paced world, cultivating a calm, soothing environment at home has never been more important. Whether you live in a busy urban apar...

How Maths Tutoring Can Help Students Master Maths

Mathematics can be a daunting subject for many students, often causing stress and frustration. However, maths tutoring has proven to be an effective...

Refurbished iPads Are Better Than New Ones (Here's Why)

Image by rawpixel.com on Freepik Apple's refurbished iPad program has quietly become one of the best deals in tech. While everyone obsesses over the ...

Your Guide to Finding the Right GP: What Perth City Doctors Offer Today

Choosing a General Practitioner (GP) is one of the most important health decisions you’ll make. Luckily, Perth’s vibrant CBD now hosts a new ge...

Why Every Mining Operation Needs a Robust Safety Management System

Mining is one of the backbones of the Australian economy, particularly in Western Australia. Back in 2019-20, mining contributed 10.4% of Australia...

Australian Classic Literature Enjoys Resurgence

Welcome back to the good old days of storytelling! As the modern world becomes increasingly more demanding, returning to childhood favourites offers...

How to Choose the Right Lawyers in Sydney for Your Situation

When faced with a legal issue, selecting the right legal representation can make all the difference. Whether you're dealing with a personal injury, ...

Building a Governance Model for Headless Content Management at Scale

Image by pch.vector on Freepik There's never been a better time to implement a headless content management system (CMS) to gain the flexibility and ...

Understanding Trade Insurance: Essential Protection for Businesses

Image by Drazen Zigic on Freepik In the current economic environment, trade insurance is an important element for companies trading both locally an...

Choosing the Right Timber for External Cladding

Timber cladding is one of those finishes that pulls double duty: it makes a building look warm and welcoming, and it quietly shields the frame from ...