Nitrogen-fixing is a natural process where certain organisms convert atmospheric nitrogen (N2) into a form that plants can use, such as ammonia (NH3). This process is essential because most plants cannot utilize nitrogen directly from the air. Instead, they rely on nitrogen-fixing bacteria, which can be found in the soil or in symbiotic relationships with the roots of some plants, like legumes (peas and clover). These bacteria, such as those in the genus Rhizobium, play a crucial role in the nitrogen cycle. By converting nitrogen into a usable form, they help enrich the soil, promoting plant growth and improving agricultural productivity. This process also reduces the need for synthetic fertilizers, making farming more sustainable.