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Influence of soil properties and organic pesticides om soil microbial metabolism

Schnürer, Ylva (2006). Influence of soil properties and organic pesticides om soil microbial metabolism. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2006:118
ISBN 91-576-7267-9
[Doctoral thesis]

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In many areas of the world undesirable dispersal of organic pesticides into untargeted environments has occurred, and is continuing, raising serious concerns about their potential impact on the environment and human health. The main agents ultimately responsible for the degradation of these substances are microorganisms, so it is important to understand their effects on microbial metabolism and the complex interactive effects of soil parameters, microbial activities, pesticide availability and pesticide degradation dynamics. The studies presented in this thesis elucidate some such interactions involving three pesticides: 2,6-dichlorobenzamide, 2,6-dichlorobenzonitrile and 2,4-dichlorophenol. The respiration kinetics of soil microorganisms in the presence and absence of pesticides were measured and used to derive information on catabolic and anabolic components of the microbial responses. Furthermore, the effects of charge density and pH of surfaces of soil particles were also investigated by manipulating soil solution pH, the pH of organic matter surfaces and the mineral composition (and hence surface charge density) of test soils. The pH and charge density of particle surfaces were found to strongly influence soil microbial processes and the fate and behaviour of pesticides in soils. In addition, the effects of sorption on the availability and degradability of glyphosate, one of the most commonly used pesticides in the world, were examined using respiration measurements in combination with attenuated total reflectance-Fourier transform infra-red spectroscopy analysis. Raising the pH of an acidic soil with high organic matter content was found to reduce the toxic effects of 2,4-dichlorophenol on anabolic microbial processes, but the effects of its toxicity towards catabolic processes were less pronounced. 2,6-dichlorobenzamide had greater negative effects on microbial metabolic processes at neutral than at acid pH. Increasing the surface charge density and raising the surface pH of the soil organic matter reduced the negative effects of 2,6-dichlorobenzonitrile on microorganisms. Soil surface charge density and pH therefore interactively influence the effects of the pesticides on microbial metabolism. Further experiments showed that sorbed glyphosate can be used by the microorganisms as a source of C, N and possibly P.

Authors/Creators:Schnürer, Ylva
Title:Influence of soil properties and organic pesticides om soil microbial metabolism
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :January 2006
Number of Pages:32
ALLSchnürer, Y., Nordgren, A., Nilsson, M., 2006. Effects of 2,6-dichlorobenzamide (BAM), 2,6-dichlorobenzonitrile (dichlobenil) and 2,4-DCP on soil microbial metabolism. Submitted Schnürer, Y., Skyllberg, U., Nilsson, M., 2006. Soil microbial responses to organic pesticides vary with soil surface charges and soil surface pH. Manuscript Schnürer Y., Persson P., Nilsson M., Nordgren A., Giesler R. 2006. Effect of surface sorption on microbial degradation of glyphosate. Environmental Science & Technology 40, 4145-4150
Place of Publication:Umeå
ISBN for printed version:91-576-7267-9
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:soil, dichlobenil, glyphosate, pesticides, soil ph, soil sorption, soil microorganisms, anabolism, catabolism, environmental impact
Keywords:Soil surface charge, Soil surface pH, Sorption, Pesticide, Dichlobenil, BAM, 2, 4-DCP, Glyphosate Respiration kinetics, SIR, Microbial metabolism, Catabolism, Anabolism
Permanent URL:
ID Code:1321
Department:(S) > Institutionen för skogsekologi (930701-061231)
Deposited By: Ylva Schnürer
Deposited On:16 Jan 2007 00:00
Metadata Last Modified:02 Dec 2014 10:11

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