Papers by Nicholas Dickinson
Carbon and trace element fluxes in the pore water of an urban soil following greenwaste compost, woody and biochar amendments, inoculated with the earthworm Lumbricus terrestris
Soil Biology and Biochemistry, 2011
The benefits of adding composted organic materials to soils to enhance carbon storage could be co... more The benefits of adding composted organic materials to soils to enhance carbon storage could be countered by the mobilisation of some harmful pollutants commonly found in frequently degraded urban soils. Therefore non-composted materials could be a safer ...
Carbon and trace element mobility in an urban soil amended with green waste compost
Journal of Soils and Sediments, 2009
Background, aim and scope The amendment of degraded urban soils using recycled organic wastes of... more Background, aim and scope The amendment of degraded urban soils using recycled organic wastes offers potential improvements to physicochemical status and functionality, but there is a paucity of knowledge on the potential impact on residual contaminants in soil. The aim of this study was to evaluate the mobility of trace metals and arsenic (As) through an urban soil following amendment with
Environmental Pollution, 2010
Three methods for predicting element mobility in soils have been applied to an iron-rich soil, co... more Three methods for predicting element mobility in soils have been applied to an iron-rich soil, contaminated with arsenic, cadmium and zinc. Soils were collected from 0 to 30 cm, 30 to 70 cm and 70 to 100 cm depths in the field and soil pore water was collected at different depths from an adjacent 100 cm deep trench. Sequential extraction and a column leaching test in the laboratory were compared to element concentrations in pore water sampled directly from the field. Arsenic showed low extractability, low leachability and occurred at low concentrations in pore water samples. Cadmium and zinc were more labile and present in higher concentrations in pore water, increasing with soil depth. Pore water sampling gave the best indication of short term element mobility when field conditions were taken into account, but further extraction and leaching procedures produced a fuller picture of element dynamics, revealing highly labile Cd deep in the soil profile.
Seabird guano and phosphorus fractionation in a rhizosphere with earthworms
Applied Soil Ecology, 2017
Soil phosphorus (P) is a critical nutrient for plant growth and is an important determinant of ve... more Soil phosphorus (P) is a critical nutrient for plant growth and is an important determinant of vegetation development and long-term ecosystem sustainability. We investigated the effects of rhizosphere-earthworm-guano interactions on soil P dynamics in a mesocosm involving two species of native New Zealand earthworms (Megascolecidae Sp.1 and Maoridrilus transalpinus) and introduced Eisenia fetida, in the context of inputs from seabird guano and the ecological restoration of a unique coastal sandplain forest. A fully factorial experimental design included a tall fibrous liliaceous perennial plant (New Zealand flax) growing in a low P forest soil, a guano-P amendment (with and without guano-P), and earthworm inoculation (with and without species of epigeics, endogeics and anecics). Soil dehydrogenase activity, CaCl2-P, citrate-P and HCl-P were significantly modified by earthworm-guano interactions, altering the P status of the original forest soil. Furthermore, interactions between the rhizosphere and earthworms stimulated transformation of soil P and guano P; the proportional importance of soil microbial biomass P, organic-P and more soluble P fractions were substantially modified. These findings show that rhizosphere-earthworm interactions are likely to mediate the supply, chemical forms and plant-availability of P, and are likely to have an important role in successional processes and the trajectory of ecological restoration in coastal forests of New Zealand.
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Papers by Nicholas Dickinson