Seasonal changes of [phenyl-U-14C]methabenzthiazuron loads in soil solution under practical farming conditions

Pütz, Th.; Mittelstaedt, W.; Führ, F.

doi:10.1016/s0045-6535(98)00148-9

Cited by 7 publications

(7 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Br − , MBT, and ETD were detected in the first leachate sampling event, 19 days after application (Figure 2). Such a rapid breakthrough suggests that preferential flow was responsible [ Pütz et al , 1998; Dressel , 2003]. This is supported by modeling [ Kasteel et al , 2006] which identified that as much as 30% of drainage occurred as rapid preferential flow in this soil.…”

Section: Resultsmentioning

confidence: 77%

“…In the 25 years prior to the experiment the mean daily air temperature at FZJ varied seasonally between −5 to 24°C in phase with the evaporation (92 mm month −1 to 9 mm month −1 ) and rainfall (78 mm month −1 to 51 mm month −1 ). The soil used in the experiments is classified as silt loam, and reportedly had earthworm burrows in abundance up to 2.5 m below ground surface [ Pütz et al , 1998]. The saturated hydraulic conductivity of the soil at 10–16 cm depth was determined to be approximately 17.5 mm h −1 [ Dressel , 2003].…”

Section: Methodsmentioning

confidence: 99%

“…The experiment entailed a 3 year lysimeter monitoring program, measuring the transport of two herbicides: methabenzthiazuron (MBT) (CAS 18691‐97‐9), isotope labeled ethidimuron (ETD) (CAS 30043‐49‐3), and a bromide tracer [ Dressel , 2003]. Preferential flow has been established as a significant component of the water balance [ Kasteel et al , 2006] and to rapidly transport pesticides [ Pütz et al , 1998] in the soils used in this experiment.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Identifying a rainfall event threshold triggering herbicide leaching by preferential flow

McGrath

Hinz

Sivapalan

et al. 2010

Water Resources Research

View full text Add to dashboard Cite

[1] How can leaching risk be assessed if the chemical flux and/or the toxicity is highly uncertain? For many strongly sorbing pesticides it is known that their transport through the unsaturated zone occurs intermittently through preferential flow, triggered by significant rainfall events. In these circumstances the timing and frequency of these rainfall events may allow quantification of leaching risk to overcome the limitations of flux prediction. In this paper we analyze the leaching behavior of bromide and two herbicides, methabenzthiazuron and ethidimuron, using data from twelve uncropped lysimeters, with high-resolution climate data, in order to identify the rainfall controls on rapid solute leaching. A regression tree analysis suggested that a coarse-scale fortnightly to monthly water balance was a good predictor of short-term increases in drainage and bromide transport. Significant short-term herbicide leaching, however, was better predicted by the occurrence of a single storm with a depth greater than a 19 mm threshold. Sampling periods where rain events exceeded this threshold accounted for between 38% and 56% of the total mass of herbicides leached during the experiment. The same threshold only accounted for between 1% and 10% of the total mass of bromide leached. On the basis of these results, we conclude that in this system, the leaching risks of strongly sorbing chemicals can be quantified by the timing and frequency of these large rainfall events. Empirical and modeling approaches are suggested to apply this frequentist approach to leaching risk assessment to other soil-climate systems.

show abstract

Section: Resultsmentioning

confidence: 77%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Identifying a rainfall event threshold triggering herbicide leaching by preferential flow

McGrath

Hinz

Sivapalan

et al. 2010

Water Resources Research

View full text Add to dashboard Cite

show abstract

“…Soil microorganisms were shown to be mainly involved in the degradation of MBTU. This herbicide is usually considered to be a member of the substituted phenylurea pesticide family; therefore, metabolites issued from N ‐demethylation of the urea function are the only ones taken into account when soil or water samples are analyzed [10–15]. However, the degradative pathway of MBTU by isolated strains is not fully understood.…”

Section: Introductionmentioning

confidence: 99%

Sequential bio- and phototransformation of the herbicide methabenzthiazuron in water

Malouki

Giry

Besse

et al. 2003

Environmental Toxicology and Chemistry

View full text Add to dashboard Cite

We investigated the transformation of methabenzthiazuron in water by microorganisms and solar light. This compound was very slowly phototransformed when irradiated at lambda > 290 nm, but it could be successfully oxidized into 6-hydroxymethabenzthiazuron by Aspergillus niger, as shown by nuclear magnetic resonance experiments. The toxicity of this metabolite, as determined by the standardized Microtox test, was sixfold lower than that of the parent molecule. The 6-hydroxymethabenzthiazuron was not further metabolized by A. niger but was photooxidized with ring cleavage of the aromatic ring and photodimerized on irradiation at lambda > 290 nm. In the presence of humic substances, the photodegradation was slower. We demonstrate that the transformations of methabenzthiazuron, observed either with the fungus A. niger or by the action of solar light, do not proceed via the urea chain N-dealkylation, as usually reported, but only via hydroxylation or cleavage of the benzene ring. This work shows the complementarity of both approaches, photo- and biodegradation, to study the fate of herbicides in the environment.

show abstract

“…This herbicide is usually considered to be a member of the substituted phenylurea pesticide family; therefore, metabolites issued from N-demeth-* To whom correspondence may be addressed (amdelort@chimie.univ-bpclermont.fr). ylation of the urea function are the only ones taken into account when soil or water samples are analyzed [10][11][12][13][14][15]. However, the degradative pathway of MBTU by isolated strains is not fully understood.…”

Section: Introductionmentioning

confidence: 99%

Sequential Bio- And Phototransformation of the Herbicide Methabenzthiazuron in Water

Malouki¹,

Giry²,

Besse³

et al. 2003

Environ Toxicol Chem

View full text Add to dashboard Cite

show abstract

Seasonal changes of [phenyl-U-14C]methabenzthiazuron loads in soil solution under practical farming conditions

Cited by 7 publications

References 13 publications

Identifying a rainfall event threshold triggering herbicide leaching by preferential flow

Identifying a rainfall event threshold triggering herbicide leaching by preferential flow

Sequential bio- and phototransformation of the herbicide methabenzthiazuron in water

Sequential Bio- And Phototransformation of the Herbicide Methabenzthiazuron in Water

Contact Info

Product

Resources

About