氨氯吡啶酸、二氯吡啶酸和2,4-滴二甲胺盐在天然草原土壤和牧草中的消解动态  

Degradation dynamics of picloram,clopyralid and 2,4-D dimethylammonium in pasture and soil of natural grassland

作　　者：牛树君[1] 王玉灵[1] 赵峰[1] 余海涛[1] 张新瑞[1] 胡冠芳[1] NIU Shujun;WANG Yuling;ZHAO Feng;YU Haitao;ZHANG Xinrui;HU Guanfang(Institute of Plant Protection,Gansu Academy of Agricultural Sciences,Lanzhou 730070,China)

机构地区：[1]甘肃省农业科学院植物保护研究所,兰州730070

出　　处：《植物保护》2025年第2期141-146,共6页Plant Protection

基　　金：甘肃省2020年草原生态修复治理科技支撑项目;大熊猫祁连山国家公园(甘肃片区)科技创新联盟科技支撑项目(GYCX[2020]03-1);甘肃省农业科学院创新项目(2022GAAS-CGZH07,2023GAAS24)。

摘　　要：除草剂混用组合2,4-滴二甲胺盐+氨氯·二氯能兼防天然草原狼毒Stellera chamaejasme、披针叶野决明Thermopsis lanceolata和黄花棘豆Oxytropis ochrocephala等多种毒草,施用除草剂后的安全放牧时间对确保家畜安全至关重要。本文采用超高效液相色谱串联质谱检测方法,研究了甘肃省肃南县天然草原土壤和牧草中二氯吡啶酸、氨氯吡啶酸和2,4-滴二甲胺盐的残留消解动态,旨在确定施用除草剂后的安全放牧时间,并评价其在土壤和牧草中的残留期长短,为制定农药最大残留限量标准提供参考。结果表明,二氯吡啶酸、氨氯吡啶酸和2,4-滴二甲胺盐在天然草原土壤和牧草中的残留消解动态曲线符合一级动力学方程,3种除草剂在土壤中的半衰期分别为16.9、26.7 d和8.6 d,在牧草中的半衰期分别为18.2、1.8 d和12.0 d,2,4-滴二甲胺盐在土壤和牧草中均属于易降解除草剂,二氯吡啶酸在土壤和牧草中残留期相对较长,氨氯吡啶酸在土壤中残留期相对长,而在牧草中则属于易降解除草剂。参照3种除草剂在牧草中的残留量和相应除草剂在矮生浆果、蔬菜、小麦、大麦、燕麦和油菜籽中的国内外最大残留限量标准评价,在天然草原喷施2,4-滴二甲胺盐+氨氯·二氯防除草原毒草,施药后30~45 d二氯吡啶酸在牧草中的残留量为4.1~2.3 mg/kg,氨氯吡啶酸在0.5 mg/kg以下,2,4-滴二甲胺盐在0.56 mg/kg以下,此期放牧,对牛、羊等家畜安全。The combination of 2,4-D dimethylammonium and picloram·clopyralid can effectively control various poisonous weeds,including Stellera chamaejasme,Thermopsis lanceolata and Oxytropis ochrocephala.Determining the safe grazing period after herbicide application is crucial for livestock safety.In this study,HPLC-MS/MS was used to analyze the degradation dynamics of clopyralid,picloram and 2,4-D dimethylammonium in pasture and soil of natural grassland in Sunan county,Gansu province.The degradation curves of the three herbicides in pasture and soil followed a first-order kinetics model.The half-lives of the three herbicides in soil were 16.9,26.7 and 8.6 days,respectively,and in pasture,18.2,1.8 and 12.0 days,respectively.2,4-D dimethylammonium was classified as easily degradable herbicide in both pasture and soil.Clopyralid showed relatively long residual period in both pasture and soil,while picloram had a longer residual period in soil but was easily degradable in pasture.Based on residues of the three herbicides in pasture and the MRLs of these herbicides in dwarf berries,vegetables,wheat,barley and rapeseed,it was determined that grazing on grasslands treated with 2,4-D dimethylammonium+picloram·clopyralid 30-45 days after herbicide application is safe.During this period,clopyralid residues ranged from 4.1 to 2.3 mg/kg,picloram was below 0.5 mg/kg,and 2,4-D dimethylammonium was below 0.56 mg/kg,ensuring the safety of cattle,sheep and other livestock.

关 键 词：二氯吡啶酸 氨氯吡啶酸 2 4-滴二甲胺盐 消解动态 土壤 牧草 

分 类 号：S812.6[农业科学—草业科学]