Cultivating Carbon: Unraveling the Secrets of Soil Health

Under the surface of every thriving farm, a subtle yet dynamic relationship unfolds between soil and carbon, coordinated by the complex web of life beneath our feet. The beneficial effects of a balanced soil microbiome — the harmonious coexistence of microorganisms like bacteria, fungi, protozoa and nematodes — are at the core of this performance. These tiny but mighty inhabitants form a vibrant underground ecosystem, enhancing soil health and resilience.

Not only does this boost agricultural production, but around the world, more farmers, producers and researchers are recognizing the power of healthy soils to capture and sequester carbon, making them a vital part of the fight against climate change.

Soil is Earth’s second-greatest carbon sink, holding three times the amount of carbon currently in the atmosphere.

The connection of soil and carbon

Carbon, a crucial building block for organic molecules, is key to life on Earth, forming the basis of all living organisms. Particularly in the form of carbon dioxide (CO₂), it also acts as a greenhouse gas, retaining heat in the atmosphere. In the past, this has helped to maintain a habitable temperature range for our planet. However, excessive carbon emissions, primarily from human activities, are now overloading the atmosphere with carbon, contributing to the harmful effects of climate change. Capturing this excessive carbon and storing it away, a process known as carbon sequestration, is essential to combating climate change — and healthy soils are the key.

Soil health depends on a range of factors, including plant diversity, deep-rooted crops, soil microbial activity, and soil organic matter (SOM). These attributes enable soil to efficiently capture and retain carbon, a process primarily moderated by plants through photosynthesis. The soil can then store this soil organic carbon (SOC) in the overall soil carbon pool.

Healthy soils have the remarkable capacity to capture and store approximately 10% of carbon emissions over the next 25 years, making them a vital player in the fight against climate change.

 

Unveiling the mechanisms: How does it work?

Soil organic matter (SOM) is a key component of soil, affecting its physical, chemical and biological properties. It consists of decomposed organic materials, from either plant or animal sources. As this organic matter is introduced to the soil through compost application or cover cropping, it sequesters carbon. Therefore, the more that soils are enriched with organic matter, the higher their carbon sequestration potential is.

Moreover, with its carbon content, SOM improves soil structure by forming stable aggregates, clumps of soil particles held together by organic matter and microorganisms. These aggregates help to create channels and pockets where carbon can be sequestered more effectively, further powering the overall carbon sequestration process. Well-formed aggregates also mitigate soil erosion and enhance water retention, creating a strong soil structure conducive to long-term carbon storage. Additionally, SOM is a critical food source for beneficial soil microorganisms.

This intricate interplay not only maximizes carbon sequestration but reinforces the fertility of the soils, making it a cornerstone of sustainable agriculture and climate change mitigation.

From cover crops to crop rotation: Implementing soil health principles

Soil can hold the equivalent of three times the atmosphere’s carbon — and nearly four times that of all living things combined. Over the past 10,000 years, however, soil carbon has declined by 840 billion metric tons of carbon dioxide (GtCO₂) worldwide, due to unbalanced agricultural practices and land conversion, and many farmed soils have lost 50–70% of their original organic carbon. This has created an exceptional opportunity for carbon sequestration. According to a recent assessment out of American University, soils could sequester 2–5 GtCO₂ per year by 2050, with a cumulative capacity of 104–130 GtCO₂ by the end of the century.

For this to happen, farmers must engage in practices that enrich the soil with organic matter, creating an environment where microorganisms thrive, enhance soil properties and aggregates, and mitigate soil erosion.

• Regenerative agriculture: This approach involves maintaining living roots in the soil throughout the year, continuously supplying organic matter and encouraging microbial activity, thus promoting carbon sequestration.
• Cover crops: Deep-rooted cover crops ensure a constant presence of living roots in the soil, protecting it from erosion, enriching it with organic matter, and enhancing its sequestration ability.
• Crop rotation: Diversifying the types of crops grown in a field aids in naturally managing pests and diseases and reduces the risk of depleting necessary nutrients.
• Soil cover: Practices like no-till farming and mulching help maintain a protective cover on the soil, minimizing carbon loss.
• Microbial fermentation and biotechnological solutions: These innovative approaches harness the power of soil microorganisms to enhance organic matter decomposition.

Reaping the benefits of carbon sequestration for crop production

It is important to remember that discontinuing such practices results in the quick release of carbon from the soil and back into the atmosphere. Therefore, it is crucial that any such changes in farm management be permanent.

Luckily, many of these approaches offer significant benefits in agricultural productivity as well as climate change mitigation.

Soil health controls the production capacity of our land. Healthy and stable soils enable farmers to better face market fluctuations and the effects of climate change. By nurturing soils and focusing on sustainable crop practices that promote biodiversity, farmers can create a healthier environment for crops and reduce reliance on chemical inputs. Improved soil quality translates to increased nutrient availability for crops, fostering robust crop growth and development and resulting in higher yields. Also, enhanced soil structures resist erosion and amplify water retention, which is especially valuable in regions subject to drought or highly irregular rainfall.

Carbon sequestration even aligns with sustainable agricultural practices at times when conventional farming methods are used, because the carbon stored in the soil acts as a buffer, reducing the carbon footprint associated with these methods.

Microbial fermentation and biotechnological solutions

In the pursuit of enhancing soil health and maximizing carbon sequestration, microbial fermentation plays a pivotal role. A natural process driven by soil microorganisms, it breaks down organic matter into stable soil organic carbon, enriching the soil and contributing significantly to carbon sequestration.

While this process is a natural one, it does not always happen at the levels needed for maximum soil health. Biotechnological solutions introduce specialized microbial communities to optimize organic matter processing and soil organic carbon formation. These innovations reduce the need for chemical inputs and foster not only carbon sequestration but overall sustainability.

The approach of boosting microbial fermentation with leading-edge biotechnological solutions offers a fresh perspective on building soil health sustainably.

In conclusion, the role of healthy soils in carbon sequestration cannot be overstated. By adopting agricultural practices that promote soil health and long-term productivity, including taking advantage of the latest developments in biotechnology, we can contribute to carbon sequestration while building a more resilient and sustainable food system for Earth’s growing population into the future.

For further insights, check out our blogs on how suppressive soils yield healthier crops and how agriculture could be carbon negative by 2050.

About the author:

Helena Estiveira is the Global Marketing and Communications Manager at Alltech Crop Science (ACS). She works closely with the ACS executive team to plan and execute the strategic marketing and communication goals of ACS.

Helena is based in Portugal, where she initially joined Alltech as European Marketing Manager for Crop Science. Prior to joining Alltech, she worked for 16 years in the advertising industry in agencies in Portugal and Brazil as an account manager and account supervisor, gaining vast experience in the pharmaceutical and bank services industries.

Helena received a bachelor’s degree in advertising from the Institution of Visual Arts in Lisbon, Portugal, and also completed a post-graduate course in marketing and communication at Instituto Superior de Novas Profissões/Lusófona in Lisbon and executive training in CRM and finances at Escola Superior de Propaganda e Marketing in São Paulo, Brazil.

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