Urea is used as fertilizer, hydrolyzed enzymatically by soil urease and the resulting release of ammonia and rise in pH. This urease activity has a deep relationship with the cropping pattern. Urease activity has negatively correlated with EC and total N and positively correlated with organic C, pH, Microbial C and N. Soil respiration showed inverse relation with soil moisture, % clay and microbial biomass C and positive correlation with soil pH and organic C. In this study showed that the cropping pattern significantly affected urease activity. The highest activity for the enzyme assayed was observed where the orchard rotation had been maintained and there exists a strong relation¬ship between soil urease activity and soil properties of different cropping patterns. Это и многое другое вы найдете в книге Evaluation of Urease Activity and Respiration (Bina Rani Majumder and Mohammad Zaber Hossain)