Cyanobacteria are important to life on Earth in many ways. The oxygen in the atmosphere that humans depend upon was largely generated by an abundance of cyanobacteria billions of years ago. Cyanobacteria help convert atmospheric nitrogen into a form that can be consumed by plants and are, therefore, useful as a natural fertilizer that is beneficial to crop cultivation around the world. Moreover, the organisms are active in reducing erosion by facilitating the binding together of soil particles and many have formed symbiotic relationships with other plants.