University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Melanie Paumann
(2017):
Copper Toxicity to Soil Microorganisms and Microbial Processes - an Ecotoxicological survey..
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 62.
UB BOKU
obvsg
- Abstract:
- The infestation with the fungus downy mildew (Plasmopara viticola) causes dramatic losses in wine production. Copper (Cu) based fungicides have been used in viticulture since 1850. Until today conventional and organic viticulture strongly rely on Cu to prevent and reduce fungal diseases. Consequently, Cu has built up in many vineyard soils and it is still unclear how this affects soil functioning. The aim of the present study is the evaluation of Cu toxicity to soil microbes. Two contrasting Cu-poor agricultural soils were sampled to conduct an eco-toxicological greenhouse pot experiment. The soils were spiked with a common fungicide based on Cu hydroxide in seven concentrations (0, 50, 100, 200, 500, 1500 and 5000 mg Cu kg-1 soil). Lucerne (Medicago sativa L. cultivar. Plato) was grown for 3 months. Sampling was conducted at the beginning and the end of the study period (t1=0, t2=100 d) to test Cu effects on total soil microbial biomass, basal respiration, enzyme activities, such as exoglucanase, β-glucosidase, exochitinase, phosphatase, protease, phenol- and peroxidase. Additionally, dissolved organic carbon, total dissolved nitrogen, nitrate and ammonium and urease activity were determined to provide further insight into the carbon and nitrogen cycle. Ergosterol was analysed as a fungal biomarker. Hydrolytic extracellular enzymes were not clearly affected by rising Cu concentrations, while a trend of decreasing and then increasing activity of oxidative enzymes was observed. Microbial respiration rate as well as the amount of microbial biomass carbon and nitrogen decreased with increasing Cu concentrations. Fungal biomass was very sensitive to Cu and started to decline at low concentrations. In summary, the results showed distinct Cu toxicity effects on soil microbial biomass with a larger sensitivity in the acidic, sandy soil. Our study showed that Cu mitigation and remediation strategies should especially target vineyards with acidic, sandy soils.
- Beurteilende(r): Zechmeister-Boltenstern Sophie
- 1.Mitwirkender: Keiblinger Katharina
- 2.Mitwirkender: Zehetner Franz