University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Elisabeth Deinhofer
(2015):
Immobilization of historically and freshly applied copper in vineyard soils using compost and biochar-based amendments.
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 65.
UB BOKU
obvsg
- Abstract:
- Since the end of the 19th century, copper (Cu)-based pesticides have been used in viticulture to prevent and reduce fungal diseases. Their continuous application has caused Cu soil concentrations to exceed biological effect levels. A long-term mitigation strategy to reduce Cu bioavailability in topsoil layers is of key importance as there are currently hardly any alternatives available for plant protection in organic viticulture. This study explored the Cu-immobilizing effects of organic soil additives based on compost and biochar (BC) in comparison to lime using batch incubation experiments with 30 g of soil. In experiment A, 6 historically Cu-contaminated vineyard soils with different soil properties (varying in pH, organic matter, texture) were treated with 12 combinations of additives at application rates equivalent to 4 and 8 t ha-1. All samples were incubated for 6 weeks at 10 °C and 50 % water holding capacity. In experiment B, the same setup was used with additionally applied Cu (250 mg Cu kg-1). Total soluble Cu was determined in 0.01 M CaCl2 extracts. To estimate changes in (toxic) Cu2+ concentrations, Cu was speciated with Visual Minteq accounting for other soil solution parameters such as dissolved organic carbon (DOC) and pH. Pure wood BC and lime reduced total soluble Cu in 3 soils; however, many of the tested additives showed little reduction or even increased total soluble Cu. Conversely, the concentration of soluble Cu2+ was strongly decreased in all studied soils, especially by compost-based additives and BCs pre-treated with citric acid. The tested additives generally showed a stronger immobilizing effect for historically present Cu compared to freshly added Cu. The results show that organic additives do not necessarily decrease total soluble Cu, but may reduce local toxicity by reducing Cu2+. The reactions to the tested additives were highly soil-specific, with strong influence of DOC, pH, soil texture and organic matter content.
- Beurteilende(r): Zehetner Franz
- 1.Mitwirkender: Keiblinger Katharina