Effect of exogenous allelochemical vanillic acid on soil enzyme activity and soil nutrient for

pepper seedling was studied in this article.The results showed that 4 kinds of soil enzyme activities were

increased along with the increase of vanillic acid concentration.Furthermore,polyphenol oxidase activity

increased by 13.3 %，compared to the control when vanillic acid concentration got 1×10^-7 mol·L^-1.The

contents of soil organic matter,available P and available K tended to decrease with the increase of vanillic

acid concentration.While the soil NO-3-N content tended to increase.Relations between the 4 soil enzyme

activities and soil organic matter content,available P and available K were significantly negative.But their

relation with soil NO-3-N contents was significantly positive or very significantly positive.