What is one primary function of legumes in soil health?

Legumes play a vital role in enhancing soil health primarily through their ability to fix nitrogen. This unique capability stems from a symbiotic relationship with bacteria found in their root nodules, specifically rhizobia. During this process, legumes convert atmospheric nitrogen, which plants cannot use directly, into ammonia, a form of nitrogen that is accessible to plants. This not only enriches the soil with nutrients but also improves its overall fertility.

Incorporating legumes into crop rotations or intercropping systems can lead to improved soil nutrient profiles, supporting both legume growth and subsequent crops. As legumes enrich the soil with nitrogen, they can reduce the need for synthetic fertilizers, promoting more sustainable agricultural practices.

While the other options address various aspects of plant interactions with the environment, they don't specifically encapsulate the primary function of legumes regarding soil health as effectively as nitrogen fixation does.