氟磺胺草醚对大豆根际土壤微生物和酶活性的影响及其在根际的降解  

Effects of fomesafen on soil microorganisms, soil enzyme activities and its degradation in soybean rhizosphere

作　　者：周世雄 魏朝俊 胡海燕[3] 高宝嘉[1] 李兆君[3] 

机构地区：[1]河北农业大学林学院,河北保定071000 [2]中华人民共和国农业部华北都市农业重点实验室,北京102206 [3]中国农业科学院农业资源与农业区划研究所侬业部植物营养与肥料重点实验室,北京100081

出　　处：《植物营养与肥料学报》2018年第1期203-211,共9页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金项目(41401578);中央级公益性科研院所基本科研业务费专项(1610132016062)资助.

摘　　要：【目的】本研究旨在探讨不同浓度氟磺胺草醚在大豆根际土壤中的微生态效应,及其在根际土壤中的降解动态,为进一步研究除草剂的残留污染提供科学依据。【方法】以中黄13号大豆为材料,采用根箱进行了模拟栽培试验。设施用氟磺胺草醚3.75 mg/kg(低)、7.5 mg/kg(中)、18.75 mg/kg(高)3个水平,以不添加氟磺胺草醚处理为对照,调查了大豆根际土壤细菌、真菌、放线菌数量,分析了根际土壤中过氧化氢酶、磷酸酶、脲酶、蔗糖酶4种酶活性,以及氟磺胺草醚在大豆根际土壤中的降解规律。【结果】低浓度氟磺胺草醚处理的大豆根际土壤细菌数量显著低于对照根际土壤(P<0.05),高浓度氟磺胺草醚处理在28 d时显著高于对照(P<0.05);中浓度氟磺胺草醚处理与对照没有显著性差异。不同浓度氟磺胺草醚处理的大豆根际土壤真菌和放线菌数量与对照差异不显著。氟磺胺草醚处理的大豆根际土壤过氧化氢酶活性与对照没有显著差异;磷酸酶活性在取样初期略有降低;低浓度氟磺胺草醚处理的土壤脲酶活性显著降低,中浓度和高浓度处理对脲酶活性表现为先刺激后抑制;高浓度氟磺胺草醚处理的蔗糖酶活性在42 d和56 d时显著低于对照。高浓度氟磺胺草醚降解速率明显高于低浓度和中浓度,并且在试验初期降解迅速;3种浓度氟磺胺草醚在大豆根际土壤中的降解均符合一级动力学方程,降解半衰期由低浓度到高浓度逐渐变短。【结论】3种浓度氟磺胺草醚总体上降低大豆根际土壤中细菌的数量,而对大豆根际土壤真菌和放线菌的数量均没有显著影响。氟磺胺草醚对大豆根际土壤过氧化氢酶活性没有显著影响,在短期内对磷酸酶活性有一定程度的抑制作用,低浓度氟磺胺草醚可以显著降低大豆根际土壤脲酶活性,而高浓度氟磺胺草醚在试验后期可以显著抑制大豆根际土壤蔗糖酶活性�[Objectives] The objective of this study is to provide foundation for further analysis of residual pollution of herbicides by investigating microecological effects of fomesafen and its degradation dynamics in the soybean rhizosphere.[Methods] A pot experiment was conducted using rhizobox cultural method and soybean as test materials in a greenhouse. Fomesafen levels of 0 mg/kg （control）, 3.75 mg/kg （low）, 7.5 mg/kg （middle） and 18.75 mg/kg （high） were applied in rhizobox soil. The numbers of bacteria, fungi and actinomycetes and activities of catalase, phosphatase, urease and invertase in the rhizosphere of soybean were determined, and the degradation dynamics of the fomesafen in the soybean rhizosphere were studied.[Results] Compared with control, the number of bacteria in the soybean rhizosphere was significantly decreased with low concentration fomesafen （P 〈 0.05）, significantly higher with high concentration on the 28th day （P 〈 0.05）, and no significant difference with middle concentration. There was no significant difference in the numbers of fungi and actinomycetes in the soybean rhizosphere between the fomesafen treatments and control. The activity of catalase was not significantly affected; the urease activity was significantly decreased with low concentration fomesafen, and increased at the first and then decreased with the middle and high concentrations; the activity of invertase with high concentration fomesafen was significantly lower than that with control （P 〈 0.05） on the 42nd and 56th days. The degradation dynamics of the three concentrations of fomesafen treatments in rhizospheric soil were all accorded with the first-order kinetics equation, with the degradation half-life period from the 99 to 231 d. The degradation of high concentration fomesafen was faster than those of the low and middle concentrations in rhizospheric soils.[Conclusions] Fomesafen has no significant impact on the number of bacteria, fungi and actinomycetes in the soybean rhizosphere, except

关 键 词：氟磺胺草醚 土壤 微生物 酶活性 

分 类 号：S154[农业科学—土壤学] S481.8[农业科学—农业基础科学]