Abstract:

Soil sterilization is one of the most efficiency methods to remit continuous cropping obstacle and the growth of strawberry plants root still exhibits significant restrained compared with that grown in normal cropping soil. A pot experiment was conducted to verify the effect of sterilizing and different kinds of fertilizer on phenolic acids in rhizosphere soil and soil enzyme activities before flowering of strawberry plants which had grown up to 60 days since transplanting. The results showed that soil sterilization or applying organic fertilizer could significantly（P < 0.05）promote phenolic acids content increasing in rhizosphere soil of strawberry plant compared with unsterilized soil and applying inorganic fertilizer，and the increasing of phenolic acid applied with vermicompost was significantly（P < 0.05）lower than that applied with cattle manure. After soil sterilization，the activity of soil polyphenol oxidase could be recovered if applying organic fertilizer. The activity of soil catalase could be faster recovered if applying organic fertilizer than inorganic fertilizer. Applying vermicompost could significantly（P < 0.05）promote the activity of soil urease compared with applying cattle manure or inorganic fertilizer. The activity of soil sucrase decreased significantly（P < 0.05）because of soil sterilization and there are no significant difference between treatments of applying different fertilizers. Overall，our results suggested that application of vermicompost which can alleviate the effects of phenolic acids in rhizosphere soil and improve soil urease and other related enzyme activity is an effective measure to alleviate soil sterilization effect on strawberry plant growth and development in a continuously mono-cropped strawberry system.

Key words: strawberry, continuous cropping problem, soil sterilization, fertilizer, phenolic acid, soil enzyme