How does the carbon cycle enhance soil fertility?

The carbon cycle enhances soil fertility primarily through the process of enriching the soil with nutrients via the decomposition of organic matter. When plants and other organic materials die, they undergo decomposition, a biological process facilitated by microorganisms such as bacteria and fungi. This decomposition breaks down complex organic compounds in plant and animal remains into simpler forms, which contribute essential nutrients to the soil, including nitrogen, phosphorus, and sulfur.

As organic matter is transformed during this process, it not only releases nutrients but also improves soil structure, increases water retention, and promotes microbial activity. This vibrant microbial community is crucial for further nutrient cycling, as well as for the overall health of the soil ecosystem, contributing to a fertile environment conducive to plant growth.

The other options do not directly relate to the core mechanism of how the carbon cycle impacts soil fertility. While oxygen release is a byproduct of photosynthesis and can benefit plant roots, it is not a primary factor in soil fertility. Increasing soil temperature can influence biological activity but does not inherently enrich the soil. Furthermore, while managing acidity levels is important for some aspects of soil health, the carbon cycle's primary role in enhancing soil fertility revolves around nutrient cycling through organic matter decomposition.