甲氰菊酯在苹果园土壤中的降解行为研究

为了评价甲氰菊酯在苹果园使用后的生态环境行为和效应，采用室内模拟方法，借助气相色谱分析技术，研究了甲氰菊酯在3种苹果园土壤中的降解半衰期与土壤理化性质和环境条件的关系。结果表明，甲氰菊酯在土壤中的降解主要是微生物降解，非生物降解所占比例较小，降解规律符合一级动力学模型，在25℃时降解半衰期为27．5～30．4d；甲氰菊酯在苹果园土壤中降解的半衰期与土壤有机质含量和土壤pH值呈显著高度负相关，常温下相关系数为0．9；综合微生物降解和非生物降解因素，苹果园土壤中甲氰菊酯降解的适宜温度是30—35℃。

Study on Residual Dynamic of Fenpropathrin in Apple Orchard Soil

In order to assess its eco-environmental behavior and effect of fenpropathrin, the degradation trends of penpropathrin in three kinds of soil planted apple was analyzed by methods of gas chromatography with Electronic Capture Detector in lab, those soils tested come from Shaanxi apple production district. The results showed that the degradation trends of fenpropathrin in apple orchard soils seemed to be attributed to activities of microbes, as the degradation trends wgs lower in sterilized soil. The degradation behaviors of fenpropathrin in apple orchard soils accorded with first order kinetics with half life from 27.5 d to 30.4 d at 25 ℃. Half lives of fenprophthrin in apple orchard soils are highly correlation with organic matter contents and pH values with correlation coefficients around minus 0.9. The most important factors affecting its degradation rate in soil are organic matter content and pH. Environment factors also affect fenpropathrin degradation rate. The half lives of fenpropathrin in apple orchard soils decreased with rising temperature. The suitable temperature for degradation of fenpropathrin was 30-35 ℃.