土壤中脲酶和磷酸酶对百草枯的响应

Response of Urease and Phosphatase in Soil to Paraquat

[目的]为评价百草枯对土壤环境质量的影响提供依据。[方法]取河南工业大学校区草地0～30cm土样，过筛混匀。分别用0（对照）、100、200、500、1000μg／g百草枯溶液处理土样，然后在25℃条件下恒温培养，培养2、6、12、20、30、45、60d时测定土样脲酶和磷酸酶的活性。[结果]百草枯对土壤脲酶活性有抑制作用，且浓度越大抑制作用越强，100μg/g百草枯处理20d对土壤脲酶活性的抑制率为4．5％，而100μg／g百草枯处理2d对土壤脲酶活性的抑制率可达60．45％；百草枯对土壤磷酸酶活性具有先抑制后刺激作用，500μg/g百草枯处理30d后土壤磷酸酶的活性为对照的126％。[结论]百草枯可在较大程度上影响土壤脲酶和磷酸酶的活性。

[ Objective ] The aim was to provide the basis for evaluating the effects of paraquat on activities of urease and phosphatase in soil. [ Method ] Soil samples from 0 - 30 cm soil layer in grassland of Henan University of technology were selected, the soil samples were treated by 0（ CK）, 100, 200,500,1 000μg/g paraquat solution after they were sieved and well mixed. And then the soil samples was cultured at 25℃. The activities of urease and phosphatase in soil were detected after 2, 6, 12, 20, 30, 45, 60 h of culture. [ Result ] Paraquat had inhibition on soil urease activity, and the bigger the conen of paraquat was the stronger the inhibition was. The inhibition rate of 100 μg/g paraquat on soil urease activity was 4.5% after 20 d of culture, but the inhibition rate of 1 000μg/g paraquat on soil urease activity reached 60.45% after 2 d of culture. Paraquat had firstly inhibition and then promotion effect on soil phosphatease activity. The soil phosphatase activity in treatment with 500μg/g paraquat was 126% of that of CK after 30 d of culture. [ Conclusion] Paraquat had effects on activities of urease and phosphatase in soil in greater degree.