Azospirillum spp. is a diazotrophic bacterium widely recognized for its plant growth-promoting abilities, attributed to both phytohormone production and nitrogen fixation. However, under natural conditions, fixed nitrogen is typically released only after bacterial death. To enhance its biofertilizer potential, efforts have focused on engineering strains capable of excreting ammonium during their active lifespan. This involves decoupling nitrogen fixation from intracellular assimilation through targeted genetic modifications. Key regulatory nodes include NifA, GlnE, GlnD, GlnB, and GlnZ, whose alterations can enable constitutive nitrogenase activity and ammonium excretion even under repressing conditions. Ammonium-excreting strains can be obtained either by directed mutagenesis or by selecting spontaneous mutants resistant to ethylenediamine (EDA), a compound toxic to glutamine synthetase-active cells. Selected strains are screened using nitrogen-free semi-solid media to assess constitutive nitrogenase activity under both nitrogen-limiting and nitrogen-rich conditions. Ammonium release is quantified through the Berthelot indophenol colorimetric method. Future prospects include integrating precision genome-editing tools such as CRISPR/Cas with synthetic circuits responsive to plant-derived rhizospheric signals, allowing context-dependent control of nitrogen metabolism. Such innovations could simulate persistent nitrogen-starvation states while maintaining symbiotic compatibility. These engineered strains hold promise for low impact, sustainable agriculture by improving nitrogen availability directly in the rhizosphere. Nevertheless, challenges remain, particularly regarding genetic stability, environmental performance, and plant interaction dynamics. Field trials and ecological risk assessments will be essential to transition these strains from laboratory models to viable agricultural technologies.