Commercially-available soil DNA extraction kits are convenient tools used in many soil ecological studies. It is well-known, however, that such kits can result in incomplete extraction and shearing of genomic DNA, both of which can lead to problems in downstream analyses. Soil microbial genomic DNA extraction using a commercially-available kit was optimized in an effort to maximize quantity and diversity of DNA extracted, while minimizing DNA shearing. Modified heating and vortex times were tested for the MoBio Power Soil DNA extraction kit protocol on sandy, organic, and clay soils. DNA was quantified using a PicoGreen fluorometric assay and shearing was determined with gel electrophoresis. Microbial community composition of DNA isolated by different methods was determined using 16s (bacterial) and 18s (fungal) rRNA profiles.