土壤微生物ATP、脱氢酶和尿素酶活性的ED_(50)值评价外源镧的生物毒性(英文)  

The ED50 Values for Assessing Lanthanum Toxicity on Microbial ATP Content and Dehydrogenase and Urease Activities of Paddy Soil

作　　者：陈浮[1,2] 杨桂山[3] 曹慧[4] 王腊春[1] 彭补拙[1] 

机构地区：[1]南京大学城市与资源学系水土模拟实验室 [2]2中国科学院南京地理与湖泊研究所,南京210009 [3]中国科学院南京地理与湖泊研究所 [4]中国科学院南京土壤研究所

出　　处：《无机化学学报》2002年第8期827-832,共6页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金重点项目(No.49831070); 中国科学院知识创新工程项目(No.KZCX2-310,311); 中国科学院红壤生态实验室开放基金联合资助(No.02008)

摘　　要：Rare earths are applied widely in Chinese agriculture to improve crops nutri tion and incidentally in fertilizers, as yet little is known of their effect on the biological function of the soil. An incubation experiment was performed to a ssess lanthanum toxicity on microbial ATP content and dehydrogenase and urease a ctivities in paddy soil, which was assayed after adding La for 4h, 1d, 1, 4, 8, and 16 weeks. The relative ED50 values were calculated by two kinetic models (mo del 1 and model 2) and one sigmoidal dose-response model (model 3). Model 1 wa s successful in calculating the ED50 values for the ATP content, dehydrogenase a nd urease activities. The ED50 values relating to ATP content and dehydrogenase and urease activities were 1086.5 and 897.8 and 1112.5 mg La kg-1 soil, respec tively. The ED50 values of ATP content and dehydrogenase activity increase with incubation time, but the ED50 value of urease activity decreases. After 16 weeks , La amendment has no inhibition of urease activity. The present dosage of mixed rare earths, about 0.15mg kg-1 soil year-1, applied in agriculture can hard ly affect ATP content and dehydrogenase and urease activities in the paddy soil even over a long period.Rare earths are applied widely in Chinese agriculture to improve crops nutri tion and incidentally in fertilizers, as yet little is known of their effect on the biological function of the soil. An incubation experiment was performed to a ssess lanthanum toxicity on microbial ATP content and dehydrogenase and urease a ctivities in paddy soil, which was assayed after adding La for 4h, 1d, 1, 4, 8, and 16 weeks. The relative ED50 values were calculated by two kinetic models (mo del 1 and model 2) and one sigmoidal dose-response model (model 3). Model 1 wa s successful in calculating the ED50 values for the ATP content, dehydrogenase a nd urease activities. The ED50 values relating to ATP content and dehydrogenase and urease activities were 1086.5 and 897.8 and 1112.5 mg La kg-1 soil, respec tively. The ED50 values of ATP content and dehydrogenase activity increase with incubation time, but the ED50 value of urease activity decreases. After 16 weeks , La amendment has no inhibition of urease activity. The present dosage of mixed rare earths, about 0.15mg kg-1 soil year-1, applied in agriculture can hard ly affect ATP content and dehydrogenase and urease activities in the paddy soil even over a long period.

关 键 词：酶活性 评价 生物毒性 外源镧 土壤微生物ATP 脱氢酶 ED50 稀土 

分 类 号：S154.3[农业科学—土壤学] X53[农业科学—农业基础科学]