What value do plants of the legume family have in the life of nature?

For the synthesis of proteins and nucleic acids, organisms need nitrogen compounds, since it is part of amino acids and nucleotides. But neither plants nor animals can use nitrogen in the air. Nitrogen-fixing bacteria form nodules on the roots of leguminous plants. They provide these plants with nitrogen and get nutrients in return. When legumes die off, the nodules are destroyed and nitro compounds enter the soil, and therefore, other plants. The legumes themselves are food for animals.