Everything about the soil

"Soil is the only magical material that turns death into life." - Sadhguru

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Soil is fundamental to life on earth. We rely on a mere 10-25 cm of topsoil to grow 95% of our food¹. In addition to food security, this thin layer of ‘dirt’ is essential for regulating climate, providing freshwater and sustaining biodiversity.

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Due to unsustainable land use, we have degraded 50% of our planet’s topsoil over the past century², and are set to lose our entire supply in the coming 60 years if we do not change our practices³. Unfortunately, nature also takes a very long time to build fertile land.

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The loss of our soils and its far-reaching consequences stands out as one of the most crucial - yet probably least well known - environmental issues we face today. With our fertile land degrading at an alarming rate, it is too late to speak about ‘sustainable land management’. What we need is regeneration. 

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Regenerative agriculture can bring back the ecological balance in our fields and restore soil health worldwide. It is the best tool to collectively address the climate, biodiversity and farming crises. 

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Here are all of your questions answered on the soil and why it is so important to mitigate climate change. 

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How does the soil relate to climate change?

‍Did you know that soil stores more CO2 than vegetation and the atmosphere combined?⁴ That’s why (healthy) soil acts as the world’s greatest carbon sink after the ocean.

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There are constant two-way exchanges in carbon dioxide between the soil, plants and the atmosphere. Soil biological processes can convert carbon dioxide into carbon in the ground  (see details in ‘How does soil carbon sequestration work?). Conversely, soil also releases carbon back into CO2 through respiration when it is exposed to the air.

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In recent decades, soil’s ability to retain its substantial carbon reservoir has been compromised. Due to unsustainable land management practices such as intensive tilling, cultivated soils have lost 50-70% of their original carbon stock⁵. While environmental historical textbooks often attribute land degradation to deforestation, the long-term culprit is the subsequent ploughing which leaves the soil bare and vulnerable to erosion. Climate change worsens these effects by increasing global temperatures and the rate of soil respiration.

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Whether soils accumulate or lose carbon – and thus act as carbon sinks or carbon sources – therefore depends on how the land is used.

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Unlocking the secrets of this complex powerhouse is key to any effort towards halting global warming. Effective climate mitigation and environmental management can only occur by acknowledging soil’s significance in the carbon cycle.

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How does soil carbon sequestration work?  

As opposed to expensive and complex carbon removal technology, regen ag is a readily available, scalable and natural way of drawing down carbon. But how, exactly, is it able to do so?

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Healthy soil is able to store carbon through photosynthesis:

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• Plants draw down carbon from the air and convert it into plant tissues.

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• Carbon is then transferred to the soil either through plants’ roots or decay once they die.

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• Microorganisms break down organic matter in the ground, ultimately turning carbon into stable organic matter, often referred to as ‘humus’.

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• This stabilised organic matter is less prone to decomposition and can persist in the soil for several years to centuries, effectively storing the carbon.

💡 Soil organic matter (SOM) is the fraction of the soil that consists of plant or animal tissue in various stages of breakdown (decomposition). Humus is stable organic matter, or the final product of decomposition and is what gives soil its dark brown colour. SOM is made of 58% carbon.

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As such, what we see as ‘storing carbon’ is equal to increasing the soil’s organic matter. The more organic matter is retained in the soil, the higher is agriculture’s mitigation potential against climate change. Regen ag involves practices which help to maintain or increase soil organic matter levels.

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(Want to know more about Regeneratie Agriculture? Check out our dedicated article here)

‍What is the role of carbon in the soil?

Regenerative agriculture’s prime focus is to ‘regenerate’ soil health through increased soil organic matter, which is mostly made up of carbon (60%)⁶. This makes carbon measurement an excellent proxy for soil health and performance. Indeed, carbon is not the enemy, rather a building block of life and a key factor in soil’s capacity to provide ecosystemic services. Beyond contributing to mitigating climate change, farmers have a vested interest in augmenting their soil’s organic carbon for fertility and agricultural productivity.

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Carbon determines the soil’s chemical, physical and biological composition, supporting its many ecosystem functions such as:

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• Soil structure: SOC works as a glue, binding nutrients and improving soil structure and stability. This enhances soil aeration and root penetration.

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• Water retention and drainage: SOC also works as a sponge, improving the soil’s ability to retain water and use it whenever needed. This reduces risks related to droughts by providing plants with water even during dry seasons. Unhealthy and parched soils cease to absorb water and become vulnerable to erosion.

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• Nutrient cycling and plant health: Carbon has unique bonding properties that allow it to combine with many essential elements like nitrogen, phosphorus, and potassium. SOC increases soil’s nutrient filtering and holding capacity.

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• Biological activity: SOC provides food for the billions of bacteria, fungi, and other soil organisms - supporting the soil’s vast biological diversity.

👀 Did you know? There are more organisms in one teaspoon of soil than there are people on earth. These microorganisms contribute to nutrient cycling, decomposition, and the prevention of plant diseases⁷.

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• Air Quality: SOC indirectly contributes to air quality by reducing the release of fine dust particles, air pollutants and other greenhouse gases such as nitrous oxide (N2O) and methane (CH4).

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On the other hand, soils with low carbon contents such as in conventional farming are more susceptible to erosion, compaction, lower crop quality and droughts.

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How do we guarantee that carbon stays in the soil?

In order to guarantee the permanence of carbon storage in the soil and compensate for potential carbon losses (release) during the programme, which can occur with a change in farming practices, we retain 20% of farmers’ generated certificates in a “buffer” each year which cannot be sold. 

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We collect agronomic data on farmers’ carbon performance each year. Additionally, we are integrating remote sensing technology through satellite data to enhance our carbon monitoring capabilities and measure potential carbon losses with utmost accuracy. If a carbon loss is confirmed during an audit, a corresponding number of certificates will be removed (cancelled) from the buffer to compensate for the loss. 

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The farmer will have to contribute the same number of certificates to the buffer again in future years before carbon payments resume. Certificates that are placed in the buffer will not be sold until the end of the 10th season after these certificates were generated. 

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Our regenerative agriculture programme along with the buffer system can guarantee a permanence of carbon storage for 15 years. 

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Sources:

1: Soil is failing across the world

2: Soil Erosion and Degradation

3: Only 60 years of farming left

4&6: Soil, the hidden part of the climate cycle

5: Soils are losing carbon

7: FAO World Soil Day