Large flows of nitrogen between the atmosphere, terrestrial and aquatic ecosystems contribute to the global cycle on Earth. When balanced, this cycle ensures that life at every level can flourish and diversify. However, in the past 50 years, humans have had a large, negative influence on nitrogen cycle pushing it beyond safe boundaries at the global level. Alternative, wholesome strategies are needed for the agricultural systems to achieve sustainability without compromising crop yields. Decades of research in the field of biological nitrogen fixation in symbiotic root nodules paved the way for ambitious bioengineering projects aiming to meet the nitrogen request in a sustainable manner. Parallel studies of the other microbes that associate with healthy plants in nature unveiled a tremendous, untapped resource for biostimulants. Many of these interactions are now worth investigating in detail to enable understanding at the molecular and ecological level and facile transfer into agricultural settings.