Nitrogen is an essential building block of life, and legumes form partnerships with bacteria in their roots that can pull nitrogen from the air and convert it to a form that plants can use in a process called biological nitrogen fixation. This enriches the soil and improves plant growth. However, the efficiency of this cooperation varies greatly with factors such as light, soil nutrients, and plant characteristics, making it difficult to predict the results of this interaction in nature. Our goal is to investigate how these factors influence the development of nitrogen fixation. The project involves creating a database of Cerrado legume traits, studying the evolution of nitrogen fixation in different strains, and conducting experiments with legumes and their bacterial partners. Ultimately, this study will allow us to identify plants with high nitrogen-fixing capacity that can contribute to soil enrichment and management of native Brazilian ecosystems.