Nitrogen input in tropical pastures increases forage and animal productivity. Forage legumes can fix atmospheric nitrogen and are the most economical way to add this nutrient to the soil. Our objective was to report the benefits of forage legumes in tropical pastures and possible strategies to implement different forage legumes. In tropical conditions, such as in Brazil, the use of forage legumes is still scarce. Even with low legume adoption on tropical pastures, forage legumes can provide ecosystem services. Increased animal productivity is the first ecosystem service provided by these legumes, mainly due to the addition of nitrogen that is typically the most limiting nutrient on tropical soils and yet the most important driver of plant growth and development. Legumes also provide an opportunity to increase nitrogen cycling in grassland, reducing grassland degradation. Pastures that include legumes have greater litter quality than grass monocultures, increasing soil organic matter at a faster rate. Legumes improve diet nutritive value and animal performance, resulting in reduced enteric methane emissions per unit of animal product. Additionally, legumes are generally associated with lower nitrous oxide emissions than N-fertilized grass swards and reduce the carbon footprint from the system due to nitrogen manufacture, transport, storage, and application. However, the greatest challenge in tropical pastures is to increase the adoption of forage legumes. It is necessary to understand the role of different legumes in the pasture environment. Some legumes have high herbage accumulation and biological nitrogen fixation potential, but they have low canopy stability; nonetheless, they could be used on short-lived pastures as well as integrated crop-livestock systems. When the objective is to achieve grass-legume stability in mixed pastures, it is necessary to use clonal propagation legumes and provide appropriate defoliation management to minimize light competition among plant communities
