Effect of Cadmium Stress on Enzyme Activity and Concentration of Mineral Nitrogen in Soil when Growing Quercus acutissima Seedlings

摘要

Quercus acutissima, soil enzymes peroxidase and invertase activities, and mineral nitrogen (NH4+-N, NO3-N) concentrations were measured on the 50th and 100th day under treatments of Cd (0, 15, 30 mg kg(-1)) with or without addition of benomyl. Results suggested enzyme activities increased with growth. A lower concentration of Cd (15 mg kg(-1)) stimulated peroxidase and invertase activities while a higher concentration of Cd (30 mg kg(-1)) produced a negative effect on invertase. Cd increased the soil NH4+-N concentration. Therefore, a lower concentration of Cd increased the NO3--N concentration while a higher concentration of Cd reduced the NO3-N concentration. Addition of benomyl had no significant effect on the two enzymes of interest and mineral nitrogen (NH4+-N and NO3--N) concentrations at the control check treatment (0 mg Cd kg(-1)).