Looking at Soil in a Different Light

Soil carbon is the buzzword around town, especially concerning carbon sequestration and net emissions reduction. Soil carbon sequestration provides farmers with opportunities for market access, improved resilience and more, but what does it actually mean?

Soil’s building blocks

Let’s start small.

When you dig up a shovel of dirt, the plant roots, insects, and fungi make up the soil’s organic matter. No matter what stage of decomposition this matter is in, it all works in a system to support plants’ growth.

If we look closer at the soil (not literally- you will need a hefty microscope otherwise), we will find that this organic matter is made from different elements. The big building blocks are hydrogen, carbon, oxygen and nitrogen, and the smaller ones are phosphorus, potassium, calcium, magnesium and sulphur (to name a few).

When these smaller elements deplete, we tend to add them back to crops with fertiliser. These elements help improve plants’ health at different stages of their lifecycle, and any excess gets dispersed into the soil and groundwater. Because the crop tends to be the product we usually have our eyes on as the money maker, this is the priority lens for most people. 

Let’s take a step back and look at things from a different lens

Say you are coming home from work each day with a bad back. You are probably helping soothe the pain with ibuprofen or a heat pack. 

Instead of reactively trying to soothe the pain, what if you took a proactive approach and spent time building the muscles to help support your body? By building muscle strength, you reduce the chances of straining your back in the first place.

If we look at soil as the body of our farm, if the priority is to take care of the soil first – rather than fertilise the crop – the result is a healthier system to support better crop growth.

So what has this all got to do with carbon? 

Well, carbon is a key chemical in environmental systems. Carbon regulates the Earth’s temperature, makes up the food that sustains us, and provides energy that fuels our global economy. Yet too much carbon released from carbon stores (e.g. soil and trees closely following the ocean) results in changes to the atmosphere’s composition and ability to regulate temperature. To combat this, we need to sequester carbon by mitigating its release in the first place and by storing additional carbon. 

Sequestering carbon in soil and plants isn’t just important to mitigate climate damage, it also affects the ecosystems where the carbon is sequestered.

Some of these benefits include:

• Improved water and nutrient retention- you won’t need as much fertiliser as often or be so reliant on rains to maintain a stable water content of your soils.
• Improved productivity of plants and crops comes with enhanced nutrient and water level stability.
• Improved crops mean more robust root systems that host fungi, improve soil structure, and reduce erosion to rainfall or livestock.
• With less soil erosion, downstream dams, lakes and rivers won’t see the same silt and sediment washed into them.
• All these little benefits culminate in increased resilience to environmental changes (i.e. our hotter summers or colder frostier winters).

So how can I go about building soil organic carbon?

Let’s look at the ten key ways you can proactively change your management plan to build soil organic carbon, as determined by the NSW Local Land Services:

1. Pasture management: be precise in what nutrients must be added and where. Be specific about what species you are planting- are they the best for your climate and soil type?
2. Grazing management: prioritise rest for your plants- yes, you heard me (or should I say herd). Reduce the ongoing grazing pressure of a paddock by moving the livestock quicker, giving the plants more time to build back their foliage.
3. Cover crops: including green manure and inter-row cropping, covers the soil across your paddocks or in-between horticultural crops. 
4. Pasture cropping: sew winter cereals into perennial pastures to build the ground cover across your paddocks.
5. Changing crop-pasture sequences: increase the frequency or duration of pastures in a cropping rotation to reduce soil disturbance and build root mass. 
6. Adding lime, gypsum, and nutrients: optimise plant growth by managing chemical and physical soil constraints.
7. Adding carbon-rich materials: start making compost, spreading manure, or biosolids like biochar or worm tea. This rich form of organic matter is a natural nutrient boost to the soil.
8. Minimising or strategically tilling: if you have ever googled no-till, you will know that by breaking open the soil, you are letting out the good elements, like when you cut open an orange and the juice flies out!
9. Stubble retention: by simply leaving the stubble, you are keeping the root biomass in the ground- maintaining the structure and integrity of the soil and the habitat for soil microbes. 
10. Restoring degraded sites: target the areas that look sad. Take some tests, find the problem and support its health. 

We wouldn’t want to keep you all day here reading, so head over to the NSW Government’s handy 10 Ways to Build Soil Carbon document to learn about these ten points and how you can incorporate them into your land practices.

Soil carbon as a carbon farming method

In Australia, you can be formally recognised for new and additional soil carbon sequestration efforts under the Emissions Reduction Fund and get rewarded carbon credits in return for measured soil carbon growth.

So, if these practices sound right up your alley, but you haven’t yet started to implement them or are looking to add additional carbon sequestering practices (see the approved list here), get in touch with the CFF team to explore the feasibility of a carbon project. 

By undertaking these soil carbon sequestering changes in a registered carbon farming project, you won’t only be getting all the benefits mentioned above, but you can also unlock a new revenue stream, or transition your operation towards carbon neutrality and new market opportunities.

Ready to find out more?

Explore our range of educational resources in our Carbon Farming Education Hub where we frequently publish educational articles, webinars, and guidebooks. 

When you’re ready to explore the feasibility of undertaking a carbon project on your property, email us at hello@carbonfarming.org.au or give us a bell at (08) 6835 1140 to be connected with one of our project facilitators.