Human-induced soil change is attracting increasing attention, yet how to quantitatively measure anthropogenic impact on changes in soil properties remains unclear. Eight selected soil properties—bulk density (BD), sand, silt, and clay content, pH, soil organic matter (SOM), total carbon (TC), and total nitrogen (TN)—at four soil depths (0–10, 10–20, 20–30, and 30–40 cm) were measured across three soil series (Gallion, Latanier and Sharkey) in south-central Louisiana, USA, to quantify changes in soil properties as a function of three contrasting land use types, i.e. forest, cropland, and Wetlands Reserve Program. Partial eta-squared values (η2) derived from two-way analysis of variance were used to quantitatively compare natural factors (soil series) and anthropogenic impact (land use) on these soil properties. Results showed that properties such as BD, pH, SOM, TC, and TN could be easily changed by anthropogenic disturbance, especially at 0–10 cm, while soil texture was mainly a natural factor. The anthropogenic factor accounted for 55.2%, 39.5%, 33.2%, and 36.0% of changes in the soil properties at 0–10, 10–20, 20–30, and 30–40 cm depth, respectively. These findings highlight the anthropogenic impact on selected soil properties.