Effect of p-Chlorophenol on Soil Respiration and Urease Activity

In natural attenuation processes, biological soil enzyme activities may change with time and the concentration of the contaminant(s) whose transformation were naturally catalyzed. Short-term irrigation in the laboratory was carried out to evaluate the effect of p-chlorophenol irrigation at different concentrations on soil urease activity of yancheng upland soil. Experiments were conducted on the top of 0-20 cm soil, adding different concentrations of p-chlorophenol (2.0, 5.0, 10.0 and 50 mg kg^-1). Enzymatic activities and soil respiration were evaluated in soil incubated at 25 plusmn 1degC for 25 days. The results showed that urease activity of p-chlorophenol treated soils varied according to the p-chlorophenol concentration added. Soil respiration was stimulated at the beginning of incubation, but it was come to the background value after 25 days. Higher concentration with stimulation was also found. The activity of soil urease decreased slightly within the first 10 days, and then increased.