Soybean seeds are enriched with proteins, as such the crop has a high demand for nitrogen. Instead of relying solely on nitrogen in the soil, soybean can produce root nodules, within which rhizobia can converts atmospheric nitrogen into a form the host plant can use – a natural process called symbiotic nitrogen fixation (SNF). It is estimated that 50-60% of the nitrogen needed for soybean production is provided by SNF; nevertheless, the crop’s need for additional nitrogen remains substantial. People tend to speculate that such an addition can be supplied by nitrogen fertilizer, but adding fertilizer, in most cases, does not result in yield increases, because the fertilizer nitrogen inhibits the activities of rhizobia. Therefore, applying fertilizer nitrogen to soybean fields is not an economical and effective way to boost yield. In FY21, we initiated a three-year project that aimed to optimize the plant’s natural process to fix more atmospheric nitrogen for enhanced yield potential and reduced use of nitrogen fertilizer. Towards this goal, we proposed three specific objectives: 1) identify and characterize 4-6 soybean genes primarily repressing nodulation; 2) create soybean overexpression/knockout (i.e., an experimental line in which a specific gene loses its function) lines with increased nodulation and/or nitrogen-fixation efficiency though the CRISPR-Cas9 (a technique enable to make a gene lose its function) based editing of these genes; 3) evaluate and identify soybean overexpression/knockout lines for enhanced productivity and grain yield. In this FY23 period, we focused primarily on Objective 3 and have achieve all as proposed. We obtained 6 stable gene-editing/overexpression lines, some of which showed enhanced symbiotic nitrogen-fixation efficiency, plant productivity, yield component traits, and altered seed composition. Field tests for additional years/environments are needed in order to translate the findings into elite soybean varieties.