Article Summary: Did you know that soils are Earth's most significant carbon absorbers, with Australian soils among the world’s healthiest, storing over 3% of the globe’s carbon stocks? Did you also know that improving your soil health on your farm can positively impact global warming? Learn why the two are inextricably linked in this article and discover why soil health is important, the benefits of fertile soils on your farm, how it might affect climate change and how you can make small changes on your farm for the greater good.

Climate change, leading to soaring temperatures and extreme weather conditions, poses a major threat to you and your farming endeavours. The once unexpected but now normal extreme weather conditions and declining yields might be taking a toll on your livelihood. 

However, studies suggest that improving soil health can be crucial in mitigating climate change, as it absorbs carbon, a major greenhouse gas. Let’s get into how improving soil can affect global warming. 

How do soils absorb carbon?

Carbon dioxide is a greenhouse gas that plants absorb during photosynthesis and convert it into plant tissue. These plants shed leaves and branches and convert the plant residue into an organic matter that makes its way to the soil. 

Microbes in the soil decompose this biomass, resulting in carbon dioxide consumption, and a portion of the original carbon is retained in the earth in the form of humus. This is how soil carbon sequestration works. The formation of soil aggregates can store more carbon by sheltering carbon particles inside a clump of soil made of tiny particles.

In short, soils are Earth's most significant carbon sink and hold the most active carbon. Earth stores more than three times the amount of carbon in the atmosphere, estimated at a whopping 2500 gigatons. Carbon absorption in the soil increases its fertility and, as a result, can help farmers like you improve yields.

The benefits of fertile soils on your farm

Australia’s soil has been found to have the most extensive organic carbon storage, with 3.5% of total global stocks in a 0-30 cm layer. But why should you care about storing the carbon in your soil? 

Aside from climate change and global warming, there are some excellent reasons why healthy soils are great news for your business:

• Fertile soils provide essential nutrients for plant growth by cycling the nutrients, reducing synthetic fertilisers' use, and providing healthy food for human health. 

• Carbon-rich soils support the soil organism to grow, which is a win-win situation that naturally helps control pests and diseases.

• A fertile soil can optimise crop yield, which grows the economy and fights against poverty. 

• Carbon-enriched soils retain good moisture that helps in dry spells. 

Australia's soils, which supply food, housing, and clothes and maintain the purity of our water sources, are the country's most valued natural resource ($1 trillion/year). Healthy soils are especially synonymous with regional communities, too, through their ties to agriculture and the environment. 

How is climate change affecting soils?

Climate change and soil quality and composition are firmly connected.

Impact on the soil surface

Climate change can reduce the soil's organic matter, which disrupts its structure. Soil’s organic matter is vital for binding the particles together. A reduction in it amplifies soil’s vulnerability to erosion and impacts its ability to water retention. 

Climate change also disturbs water levels, worsening soil health. Extreme downpours can induce runoff, leading to soil erosion. Similarly, droughts and floods also damage the soil. Climate change is fading soil's ability to soak up the water, affecting fertility. 

Impact below the soil

What is happening below the soil? Climate change is causing trouble for "soil carbon", too. This is the special ingredient that makes the soil healthy. With the increase in climate change, soil carbon is reducing. 5 to 20 cm of heated soil would release 9 to 12% more carbon dioxide than usual. 

However, deeper soil layers hold more than 50% of the world's soil carbon. Scientists heated soils to a depth of 100 cm and discovered that four degrees warming might cause soils to release up to 37% more carbon dioxide than typical.

Studies show that microorganisms will have more carbon in the fast pool as CO2 levels rise and plants grow and secrete root exudates. This increases CO2 breakdown and respiration by microbes. Some simulations predict enhanced microbial respiration could turn soils into carbon sources later this century. It would be a major setback in combating climate change. 

Less tilling: The secret to increased carbon absorption

Research has shown some exciting and effective ways to boost soil carbon levels. You can increase carbon absorption by the way you till your soil. Traditionally, digging, stirring, and overturning prepare the ground for agriculture. 

Traditional tillage methods can disturb the soil structure, releasing most of the stored carbon by disturbing the soil structure.The less tillage, the more carbon is kept below.

Less tilling significantly reduces soil erosion, which helps maintain soil fertility and increase crop yield. There are many ways to minimise tilling and replace it with other soil preparation methods.  

So what does it mean to you? Read along to find out. 

How can you improve soil health on your farm?

Limiting soil disturbance is the secret to improving soil health on your farm and increasing carbon absorption. Here are some ways to do so. 

Crop rotation

You could increase the amount of carbon they sequester in their soils by altering their crop rotation, growing cover crops like clover, or utilising direct drilling, which allows crops to be sown without ploughing. If you're a livestock farmer, consider growing more natural grasses to enhance your soils.

Less diverse crops

There must be a balance between growing different crops, as the diversity of crops can also disturb the soil. The variety of crops is good, but growing more than enough would lead to soil erosion by planting and harvesting.

Reducing the use of pesticides and fertilisers 

Overuse of chemicals disturbs soils' natural pH. Non-chemical management techniques can lessen the use of chemicals. Consider using beneficial insects, growing plants, and manual techniques like setting traps, mulching, and hand weeding.

Limiting grazing activities

If you have livestock, rotational grazing is something you should think about to prevent overgrazing. This allows the land and its microorganisms to recover over extended periods.

Combining these activities with the implementation of soil sensors to help you manage your tasks with precision will ensure you’re giving yourself the best chance of having the most nutrient-rich soil possible.

Your soil is not just a piece of land. It's a powerful tool against global warming. You can change your farming techniques to lessen soil disturbance and enhance carbon absorption. You can mitigate climate change by producing healthier and fertile soil. It's not only a win for your farm. It's a win for the whole planet.

Until we meet again, Happy Farming!

- The Dedicated Team of Pasture.io, 2023-08-22