The issues of severe soil and water loss and weak erosion resistance in the Loess Plateau region are primarily attributed to the low strength and poor water stability of loess. Soybean urease-induced calcium carbonate deposition is a green and low-carbon biological soil stabilization technology

in which the calcium source critically influences the mechanical and hydraulic properties of the solidified soil. Three calcium sources

calcium chloride

calcium acetate

and calcium nitrate

were selected to prepare cementation solutions for treating loess

with a control group established for comparative analysis of the solidification effects. A series of macro- and micro-tests were conducted on the loess solidified with different calcium sources to clarify the development patterns and interrelationships among macro- and micro-indicators

including strength

failure characteristics

disintegration evolution

calcium carbonate content (CCC)

mineral composition

and micromorphology

under varying cementation solution concentrations and curing periods. The results demonstrate that the unconfined compressive strength (UCS) of calcium nitrate-solidified soil reached 1 857.24 kPa

approximately 1.91 times higher than that of the control group. The calcium chloride-solidified soil exhibited the best disintegration resistance

with disintegration time extended by up to nearly 3.52 times. The UCS and disintegration time of the solidified soil showed linear and exponential relationships with CCC

respectively. The calcite crystals induced by soybean urease reshape the microstructure of loess through cementation

filling

and encapsulation

enhancing particle compactness and overall integrity

thereby significantly improving the strength and water stability of loess. This study provides robust support for selecting the optimal calcium source in soybean urease-solidified loess.