Relationships Between Soil Urease Activity and Other Soil Properties

Surface samples of 21 diverse Iowa soils representing a wide range in pH, texture, and organic matter content were studied to determine the relationships between soil urease activity and other soil properties. Simple correlation analyses showed that urease activity was correlated very highly significantly with organic C ( r = 0.72***), total N ( r = 0.71***), and cation‐exchange capacity ( r = 0.67***). Urease activity also was significantly correlated with clay (0.53*), sand (−0.47*), and surface area (0.45*), but was not significantly correlated with pH, silt, or CaCO 3 equivalent. Multiple regression analyses showed that organic matter content accounted for most of the variation in urease activity.