土壤中脲酶和磷酸酶对百草枯的响应

[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0~30 cm土样,过筛混匀。分别用0(对照)、100、200、500、1 000μg/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、60 d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20 d对土壤脲酶活性的抑制率为4.5%,而1 000μg/g百草枯处理2 d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30 d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。

Response of Urease and Phosphatase in Soil to Paraquat

[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, 500,1 000 μg/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 concn 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 1 000 μg/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 500 μg/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.