Regulation of urea hydrolyses in soils using some organic compounds

ABSTRACT

The inhibitory effects of eleven organic compounds on soil urease activity were studied. The most effective three compounds in retardation of urea degradation were investigated as regulators of the hydrolysis of urea in silty clay soil. The use of hydroquinone, catechol and caffeic acid as regulators of urea-N transformation in soil as well as ammonia volatilization revealed the capacity of such compounds to retard hydrolysis of urea and the nitrification process. They promoted the accumulation of NH, -N and decreased the NO2- and NO3-N formation. These activities qualify these compounds to be useful as regulators of urea-N transformation aiming at the reduction of nitrite toxicity problems associated with the use of urea as fertilizer. They also could decrease the possibility of gaseous loss of urea-N through chemodenitrification and reduce the contribution of fertilizer urea to nitrate enrichment of ground and surface water. However, the gaseous loss of urea-N as ammonia still remains a problem, especially in alkaline soil