Determining Soil Carbon Storage Potential

Protecting the climate whilst reaping a good harvest is possible if greater amounts of carbon are sequestered in the soil. Agroscope calculated the amount of additional carbon that the soil is capable of storing.

Storing more carbon in the soil reduces the amount of greenhouse gases in the atmosphere and promotes soil fertility and good harvests. With appropriate management, optimal values can be achieved, which protects the environment and pays off in economic terms. In this context, Agroscope conducted a study to estimate the additional amount of carbon that can be stored in arable soils.

Type of crop rotation is key

The study showed that average carbon saturation in farmland is 62% in the top 20cm of the soil. This means a high carbon-storage potential.  The longer arable land is covered with grass and clover, the higher the carbon saturation will be. This is why temporary grasslands in the crop rotation have a major influence on the amount of carbon stored in the soil.

Ratio of organic carbon to clay constituents

Most arable soils have a carbon-to-clay-content ratio below 1:10 in the top 20cm – a threshold value below which soil structural quality no longer permits sufficient resistance to mechanical stress or water stress. Low soil organic-matter content requires a higher application of fertiliser, especially nitrogen fertiliser. Consequently, increasing the carbon content of arable soils not only benefits the climate, but also improves soil fertility.