What ability does alfalfa have regarding atmospheric nitrogen?

Alfalfa possesses a unique ability to engage in a symbiotic relationship with certain bacteria, particularly those in the genus Rhizobium, which reside in nodules on its roots. Through this relationship, alfalfa can fix atmospheric nitrogen, converting it into a form that the plant can utilize, specifically nitrates. This process is a critical component of the nitrogen cycle, allowing alfalfa to access a vital nutrient directly from the atmosphere.

The conversion to nitrates makes nitrogen available not only for alfalfa's growth but also enriches the soil with this essential nutrient, benefiting subsequent crops planted in the same area. This ability to effectively harness atmospheric nitrogen and convert it into a usable form plays a significant role in sustainable agriculture, as it reduces the necessity for synthetic nitrogen fertilizers.