Abstract
The effects of the urease inhibitors, catechol and p-benzoquinone, and temperature on the hydrolysis of urea in five soils were investigated in a laboratory study. Urea hydrolysis decreased significantly with the amount of inhibitors applied and increased significantly with each 5 °C increase in temperature from 5 to 25 °C. The effectiveness of inhibitors generally decreased with increases in temperature from 5 to 25 °C. The correlation of hydrolysis of urea with organic matter contents of the soils was highly significant (r = 0.67** to 0.86**). Both catechol and p-benzoquinone tended to increase the energies and entropies of activation of soil urease and the effect was enhanced with a decrease in soil organic matter. It is suggested that an increase in the activation energy of the soil urease as a result of inhibitor use was related to an increase in the effectiveness of the inhibitor. Key words: Urease inhibitors, urea hydrolysis, energy of activation

This publication has 7 references indexed in Scilit: