土壤中呋喃丹杀虫双p'p-DDT对蚯蚓的单一及复合毒性的研究

Single and Binary-Combined Toxicology of Carbofuran, Dimehypo and p'p-DDT on Earthworms

采用江苏省常熟农业生态试验站土壤,均匀混入农药后,调节适当的土壤水分,在人工气候箱内保持温度为20℃、湿度为80%的条件下,分别在第2、4、7、10、15d观察蚯蚓(赤子爱胜蚓Eiseniafoetida)的急性中毒状态及死亡情况并进行数据分析。结果表明,蚯蚓在含有单一杀虫双和呋喃丹的土壤中,分别表现出不同的中毒状态和毒性效应,呋喃丹大于杀虫双对蚯蚓的毒性。在10d时杀虫双及呋喃丹的LC50分别为227.57mg·kg-1和28.28mg·kg-1。当土壤中杀虫双和呋喃丹2种农药复合存在时,蚯蚓主要表现为呋喃丹的中毒状态,2种农药复合后对蚯蚓的致死毒性有显著的影响。本文还研究了p'p-DDT作为背景时,2种农药分别对蚯蚓的复合毒性。结果发现,当土壤中p'p-DDT的含量为10mg·kg-1时,无论是单一还是复合对蚯蚓的毒性基本上没有表现出明显的影响。

Single and binary-combined acute toxicology of carbofuran, dimehypo and p＇p-DDT on earthworms （Eiseniafoetida） in soil were studied respectively. The soil without residue of carbofuran and dimehypo was obtained from Changshu agricultural ecological station in Jiangsu province of China, with the following basic physical and chemical properties： the content of organic material 2.42%, the pH value 6.8, the content of total nitrogen and total phosphorus 428 mg·kg^-1 and 8.4 mg·kg^-1 respectively. The experiment was designed with 6 treatment groups, 3 replicates, each consisting of 500 g soll with appropriate water content and 15 earthworms, and conditioned in programmable artificial climate incubator with temperature 20 ℃ and humidity 80%. At 2, 4, 7 10 and 15 days, the earthworms were removed fronl soll to assess their mortality and symptoms. The earthworms showed different symptoms and moralities under different soil environments polluted by the three pesticides. The symptom of earthworm under the binary-combined pesticides of carbofuran and dimehypo was similar to that of carbofuran, but the combined pesticides affected the earthworms apparently. 10mg·kg^-1 of p’p-DDT in soil played minor role either in single or in binary-combined pesticides. The primary information about the single and combined toxicology of the three pesticides on earthworm under soil environment provided some information for pesticides management and made some fundamental work for researching the mechanism of combined toxicology.