Synthesis of earthworm trace metal uptake and bioaccumulation data: role of soil concentration, earthworm ecophysiology, and experimental design

Trace metals can be essential for organo-metallic structures and oxidation-reduction in metabolic processes or may cause acute or chronic toxicity at elevated concentrations. The uptake of trace metals by earthworms can cause transfer from immobilized pools in the soil to predators within terrestrial food chains. We report a synthesis and evaluation of uptake and bioaccumulation empirical data across different metals, earthworm genera, ecophysiological groups, soil properties, and experimental conditions (metal source, uptake duration, soil extraction method). Peer-reviewed datasets were extracted from manuscripts published before June 2019. The 56 studies contained 3513 soil-earthworm trace metal concentration paired data sets across 11 trace metals (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Sb, U, Zn). Across all field and laboratory experiments studied, the median concentrations of Hg, Pb, and Cd in earthworm tissues that were above concentrations known to be hazardous for consumption by small mammals and avian predators but not for Cu, Zn, Cr, Ni, and As. Power regressions show only Hg and Cd earthworm tissue concentrations were well-correlated with soil concentrations with R2 > 0.25. However, generalized linear mixed-effect models reveal that earthworm concentrations were significantly correlated with soil concentrations for log-transformed Hg, Cd, Cu, Zn, As, Sb (p < 0.05). Factors that significantly contributed to these relationships included earthworm genera, ecophysiological group, soil pH, and organic matter content. Moreover, spiking soils with metal salts, shortening the duration of exposure, and measuring exchangeable soil concentrations resulted in significantly higher trace metal uptake or greater bioaccumulation factors. Our results highlight that earthworms are able to consistently bioaccumulate toxic metals (Hg and Cd only) across field and laboratory conditions. However, future experiments should incorporate greater suites of trace metals, broader genera of earthworms, and more diverse laboratory and field settings to generate data to devise universal quantitative relationships between soil and earthworm tissue concentrations

Einfluss des Einsatzes von Wurmkompost auf mikrobiologische und biochemische Eigenschaften des Kultursubstrates in der Olivenbaumkultur]

In this study, olive tree has been cultivated by applying vermicompost as the organic fertilizer with different doses (0, 5, 10, 20, 40%) and single dose of chemical fertilizer (100% production material?+ chemical fertilizer) which is commonly used by the farmers of the region. During the experiment ’Gemlik’ olive has been grown in 36 pots with 6 applications, 3 replications and 2 seasons. The experiment was conducted in laboratory and under controlled conditions for 6 months. At the end of the third and sixth months, CO2-production analyses were applied to the production materials together with alkaline phosphatase and dehydrogenase enzyme activities. According to the experiment results, the effects of the production material applications on CO2 production, alkaline phosphatase and dehydrogenase enzyme activities have been considered as p?&lt; 0.01 significant statistically when the averages of 6?month trial process were examined. © 2019, Springer-Verlag GmbH Deutschland, ein Teil von Springer Nature