土壤中苯氧羧酸类除草剂的降解动态

在室内模拟条件下研究了 2甲 4氯、2,4-D和除草醚在土壤中的降解动态 .将它们放在 3种不同有机质含量的土壤中培养 ,隔一段时间取出测定它们在土壤中的含量 ,发现随着时间的延长 ,它们的含量在逐渐减少 .在未考虑土壤中微生物的作用时 ,上述 3种农药在土壤中的稳定性与土壤中的有机质含量及 pH值似乎存在一定的相关性 .除草剂在有机质含量高的土壤中降解较快 ,2甲 4氯 ,2 ,4-D和除草醚在黑土中的降解半衰期分别为 28.6d,27.3d,71.5d;而在红土中的降解半衰期分别为223.6d,301.4d,97.6d,苯氧羧酸类除草剂在酸性土壤中表现得更为稳定 .

The Degradation Trends of Phenoxyacetic Acid Herbicides in Soils

The degradation trends of MCPA,2,4 D and nitrofen in soils under the simulated conditions in the laboratory was performed.They were incubated in three kinds of soils with different contents of organic matter.Their contents in soils were determined at a period of time.It was discovered that their contents were diminished gradually with the time.Without thinking of the effect of different microbe in soils,the stability of three pesticides seems to have a relation with the contents of organic matter and the value of pH.Herbicides degraded more quickly in the soils with higher contents of organic matter than those with lower contents of organic matter.The half life value of MCPA,2,4 D and nitrofen in black soil was 28.6d,27.3d,71.5d and in red soil 223.6d,31.4d and 97.6d respectively.Phenixyacetic acid herbicides are more stable in the acid soils.