Which organism is most commonly associated with the process of nitrogen fixation in soil?

Nitrogen fixation is a crucial process in the nitrogen cycle, where atmospheric nitrogen (N2) is converted into a form that plants can use, such as ammonia. This process is primarily carried out by certain types of bacteria, with Rhizobium bacteria being the most well-known and widely studied among them. Rhizobium establishes a symbiotic relationship with leguminous plants, forming nodules on their roots where the nitrogen fixation occurs.

These bacteria possess the enzyme nitrogenase, which enables them to convert atmospheric nitrogen into ammonia, thus enriching the soil and benefiting the plants. This process not only aids in plant growth but also contributes to soil fertility, making it a key aspect of sustainable agriculture.

While fungi, protozoa, and actinomycetes play roles in soil health and nutrient cycling, they are not primarily responsible for nitrogen fixation as Rhizobium bacteria are. 이는 조건으로 인해 Rhizobium bacteria are recognized as the main agents of this essential biological process in agriculture.