Urease activity in soils: A review

Abstract

Extensive literature on the unique soil enzyme urease is reviewed and presented to create vigilance among local scientists, and to motivate them to conduct more research on urease activity under Sri Lankan conditions. Soil urease is mainly microbial in origin, and its activity in soils is due to accumulated urease. However, comparison of reported urease activity levels in different soils was extremely difficult as the assay procedures adopted in the various studies were different. Further, this enzyme is remarkably stable in organo-mineral complexes found in soil. Factors affecting urease activity and correlations between urease activity and soil properties are discussed. Problems associated with high urease activity, i.e. gaseous loss of N and plant damage due to ammonia gas and accumulated nitrite, and the effectiveness of most recently found compounds in overcoming these problems are also discussed.