What is Soil Organic Carbon?
SOC refers to “The carbon stored in the soil in the form of organic matter, such as decomposed plant and animal materials”. Implementing SOC-focused strategies can have multiple benefits, including enhancing soil health, improving water retention, reducing greenhouse gas emissions, and increasing the amount of carbon storage in the soil thus, increasing the resilience of agricultural systems to climate change impacts. Necessitating a shift to regenerative agricultural practices that improve SOC is the most critical pathway to rejuvenating the soil.
What are the key points to consider?
Increasing SOC levels in agricultural soils help sequester atmospheric carbon dioxide. Plants absorb CO2 during photosynthesis and convert it into organic matter, which upon decay is incorporated into the soil. By adopting practices that enhance organic matter in the soil, such as cover cropping, crop rotation, growing leguminous crops, and the addition of organic amendments like compost or manure, farmers can actively contribute to carbon sequestration and mitigate climate change.
Soil Health and Fertility
SOC is a vital component of soil health and fertility. It improves soil structure, water-holding capacity, nutrient availability, and microbial activity. Healthy soils with high SOC content are more resilient to extreme weather events like drought and heavy rainfall, as they can better retain moisture and withstand nutrient leaching. This, in turn, helps sustain crop productivity and reduces vulnerability to climate variability.
Reduced Erosion and Nutrient Loss
Soils with higher SOC levels have improved structure and stability, which reduces erosion of soil by wind and water. Organic matter acts as a binder, holding soil particles together and preventing their detachment and transport. Furthermore, SOC can help retain nutrients in the root zone, reducing nutrient runoff and enhancing plant nutrient-use efficiency. This is particularly important in areas prone to nutrient pollution of water bodies.
Increasing SOC content enhances the water-holding capacity of soils, improving their ability to store and slowly release water to plants during dry periods. This can contribute to more efficient water use in agriculture, reducing the need for irrigation and buffering against drought stress.
Mitigation of Greenhouse Gas Emissions
By increasing SOC levels, farmers can reduce greenhouse gas emissions from agricultural lands. High SOC content promotes conditions favourable for the growth of beneficial soil microorganisms that can help suppress the emission of nitrous oxide (a potent greenhouse gas) and methane. Additionally, practices like conservation tillage, agroforestry, and rotational grazing can help reduce emissions and improve carbon sequestration.
How can we adopt SOC-focused practices?
Encouraging farmers to adopt SOC-focused practices requires awareness, education, training, capacity building, and support. Governments, agricultural extension services, and research institutions play a crucial role in providing guidance, training, and financial incentives to farmers. Additionally, partnerships between farmers, scientists, and other stakeholders can facilitate knowledge sharing and the development of context-specific strategies.
Overall, adopting practices that enhance soil organic carbon is an essential strategy for building climate resilience in agriculture. It not only contributes to climate change mitigation but also improves soil health, water management, and nutrient cycling, making agricultural systems more robust in the face of climate challenges.