Urease enzyme activities in soils of the Batinah region of the Sultanate of Oman

Soil urease (SU) activity was measured in the surface layer (0–25 cm deep) of 26 soils of the Batinah region of Oman sampled from virgin desert, lime, alfalfa and date producing areas. SU activities were generally low, with a mean of 9•4 μg ammonium ions released g−1soil h−1. Multiple regression analysis revealed that over 80% of the variance in SU activities could be accounted for by differences in soil properties. The effects of soil salinity and organic carbon concentrations on SU activities under contrasting cultivation practices are discussed.