Either　microbial　or　enzyme-induced　carbonate　precipitation　(MICP　or　EICP)　has　emerged　to　provide　an　alternative　to　cement-based　ground　improvement　methods.　For　EICP,　either　plant　urease　or　bacterial　enzyme　can　be　used.　The　effect　of　treatments　can　differ　when　different　methods　are　adopted.　In　this　study,　the　soil　improvement　effects　for　three　methods　were　compared.　The　newly　developed　one-phase-low-pH　method　was　adopted　for　both　the　MICP　and　EICP　processes　in　this　study.　The　crude　urease　enzyme　was　extracted　from　soybean　and　urease-producing　bacteria.　The　results　show　that　the　amount　of　calcium　carbonate　induced　by　the　crude　soybean　urease　enzyme　is　comparable　to　that　produced　by　bacteria　or　bacterial　urease　under　the　same　urease　activity.　However,　the　treatment　using　the　crude　soybean　urease　enzyme　has　the　advantage　of　being　more　effective　in　enhancing　the　strength　and　reducing　the　permeability　of　soil　than　the　other　two　treatments,　especially　for　soil　with　small　grain　sizes.　This　can　be　explained　by　the　difference　in　the　precipitation　pattern　of　calcium　carbonate　using　various　urea　hydrolysis　media.