Abstract: By using soil sterilization,this paper studied the effects of biotic factors on the growth and development of three years continuously cropped pepper and its active oxygen scavenging enzyme activities,and approached the effects of soil sterilization on preventing continuous pepper cropping obstacles.The results showed that the pepper plant height,stem diameter,leaf area,chlorophyll content,fresh weight of aboveground part and roots,and root vigor were higher in sterilized than in non-sterilized treatment,while the activities of superoxide dismutase (SOD) and peroxidase (POD) were declined,which indicated that soil sterilization improved plant haleness,but reduced the activities of active oxygen scavenging enzymes.Compared with monoculture soil treatment,the haleness of pepper plant was significantly poorer,and the activities of SOD and POD were higher.It was possible that soil sterilization could effectively overcome the barrier caused by harmful microbes,but not hurdle the barrier caused by allelochemicals.

Key words: Degradation, Phenanthrene, Polycyclic aromatic hydrocarbons, Bsphaericus