Degradation of Mecoprop and Isoproturon in Soil Influence of Initial Concentration

Helweg, A.; Fomsgaard, Inge S.; Reffstrup, Trine Klein; S⊘rensen, Henrik

doi:10.1080/03067319808032610

Cited by 20 publications

(15 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This disappearance was much more rapid when initial concentration of the herbicide was low. A similar phenomenon was observed with different concentrations of isoproturon in soils containing another oligochaete (Lumbricus terrestris, Mosleh et al, 2003a) or not (Helweg et al, 1998). Disappearance of the herbicide was due (at least in part) to degradation as indicated by the appearance of metabolites in the water.…”

Section: Fate Of Isoproturonsupporting

confidence: 65%

Effects of the Herbicide Isoproturon on Metallothioneins, Growth, and Antioxidative Defenses in the Aquatic Worm Tubifex tubifex (Oligochaeta, Tubificidae)

et al. 2005

View full text Add to dashboard Cite

Metallothioneins (MTs) are low molecular weight proteins, mainly implicated in metal ion detoxification. Increase in MT contents is considered to be a specific biomarker of metal exposure. Recently it has been demonstrated that MTs participate in several cellular functions such as regulation of growth, and antioxidative defenses. Therefore, the induction of MTs as biomarkers of exposure to the pesticide isoproturon has been investigated in the aquatic worms Tubifex tubifex. MT levels in exposed worms increased significantly (p < 0.05) after 2, 4, and 7 days of exposure to different concentrations of isoproturon (maximum increase compared to unexposed controls: +148.56% for 10 mg l(-1) after 4 days of exposure). In response to isoproturon, the activity of glutathione-S-transferase (max. +52%), glutathione-reductase (max. +100%), and catalase (max. +117%) increased, demonstrating the occurrence of an oxidative stress response to the herbicide. Thus, the increase in MT contents caused by isoproturon was interpreted as a defense response towards increased oxidative stress generated by the herbicide. Residues of isoproturon and its metabolites, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl) urea, and 4-isopropylanilin were detected in the worm growth medium. Half-life of the herbicide was shorter at a low (0.1 mg l(-1)) initial concentration. The herbicide accumulated in T. tubifex but no metabolite could be detected.

show abstract

Section: Fate Of Isoproturonsupporting

confidence: 65%

Effects of the Herbicide Isoproturon on Metallothioneins, Growth, and Antioxidative Defenses in the Aquatic Worm Tubifex tubifex (Oligochaeta, Tubificidae)

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Although sorbed organic compounds are generally considered as not directly available for microorganisms, it has also been suggested that certain sorbed substrates can be directly degraded by extracellular enzymes or biomass even when the enzyme/biomass itself is sorbed . In addition, the supports (HT‐OLE and HT‐ELA) could have positively affected the number and/or the activity of metalaxyl‐degrading microorganisms or enzymes, for instance by stimulating microbial growth, by adsorbing the degrader microorganisms or by avoiding too high concentrations of the fungicide in the aqueous phase that could exert an adverse (toxic) effect on the soil microbial population . The interactions of organoclays with microbial growth and activity in soil are poorly documented, so that additional information is needed on this subject to gain a better understanding of the soil functioning in the presence of this kind of exogenous material …”

Section: Resultsmentioning

confidence: 99%

“…46,47 In addition, the supports (HT-OLE and HT-ELA) could have positively affected the number and/or the activity of metalaxyl-degrading microorganisms or enzymes, for instance by stimulating microbial growth, 48 by adsorbing the degrader microorganisms 49 or by avoiding too high concentrations of the fungicide in the aqueous phase that could exert an adverse (toxic) effect on the soil microbial population. 29,50 The interactions of organoclays with microbial growth and activity in soil are poorly documented, so that additional information is needed on this subject to gain a better understanding of the soil functioning in the presence of this kind of exogenous material. 48,51 Figures 4 and 5 show the breakthrough curves (BTCs) for Sand R-metalaxyl obtained in the column leaching experiment.…”

Section: S-metalaxyl R-metalaxylmentioning

confidence: 99%

Effect of formulation and repeated applications on the enantioselectivity of metalaxyl dissipation and leaching in soil

Celis

Gámiz

Adelino

et al. 2015

Pest Management Science

View full text Add to dashboard Cite

show abstract

“…Although pesticides were effectively retained in the lined system, residues levels of ≤52% were still recovered after 12 months. Generally, persistence increases with increasing concentration,25, 37–40 and, at high concentrations, pesticides have been shown to depress microbial biomass and bioactivity; consequently, degradation may have been inhibited 39. In many agricultural situations the use of tank mixes and complex spray programmes is common practice 34, 41, 42.…”

Section: Discussionmentioning

confidence: 99%

Degradation and leaching potential of pesticides in biobed systems

Fogg¹,

Boxall²,

Walker³

et al. 2004

Pest Management Science

View full text Add to dashboard Cite

Biobeds provide a potential solution to pesticide contamination of surface waters arising from the farmyard. Previous work has shown that biobeds can effectively treat spills and splashes of pesticide. This study investigated the potential for biobeds to treat much larger volumes and amounts of pesticide waste not only arising from spills but also from washing processes. Two systems were assessed using a range of pesticides at the semi-field scale, ie a lined biobed system and an unlined system. Studies using the lined biobeds demonstrated that water management was crucial, with biobeds needing to be covered to exclude rain-water. Once covered, the top of the biobed became hydrophobic, restricting moisture loss and resulting in saturated conditions at depth. The drying out of the top layer coincided with a measured decrease in microbial biomass in the treated biobeds. Applied pesticides were effectively retained within the 0-5 cm layer. Whilst all pesticides tested degraded, low moisture content and microbial activity meant degradation rates were low. Studies using unlined biobeds showed that only the most mobile pesticides leached, and for these > 99% was removed by the system, with a significant proportion degraded within 9 months. Peak concentrations of the two most mobile pesticides did however exceeded the limits that are likely to be required by regulatory bodies. However, it is thought that these limits could be reached by optimisation of the system.

show abstract

Degradation of Mecoprop and Isoproturon in Soil Influence of Initial Concentration

Cited by 20 publications

References 22 publications

Effects of the Herbicide Isoproturon on Metallothioneins, Growth, and Antioxidative Defenses in the Aquatic Worm Tubifex tubifex (Oligochaeta, Tubificidae)

Effects of the Herbicide Isoproturon on Metallothioneins, Growth, and Antioxidative Defenses in the Aquatic Worm Tubifex tubifex (Oligochaeta, Tubificidae)

Effect of formulation and repeated applications on the enantioselectivity of metalaxyl dissipation and leaching in soil

Degradation and leaching potential of pesticides in biobed systems

Contact Info

Product

Resources

About