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J. H. Day

Bio: J. H. Day is an academic researcher. The author has contributed to research in topics: Spodic soil & Oxalate. The author has an hindex of 1, co-authored 1 publications receiving 1768 citations.

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Journal ArticleDOI
TL;DR: In this paper, acid ammonium oxalate extracts and in dithionite-citrate-bicarbonate extracts of a wide range of Canadian soils, several oxide and silicate minerals, and some amorphous preparations of iron or aluminum and silica.
Abstract: Iron and aluminum were determined in acid ammonium oxalate extracts and in dithionite–citrate–bicarbonate extracts of a wide range of Canadian soils, several oxide and silicate minerals, and some amorphous preparations of iron or aluminum and silica. The oxalate extraction dissolved much of the iron and aluminum from the amorphous materials but very little from crystalline oxides, whereas the dithionite extraction dissolved a large proportion of the crystalline iron oxides as well as much of the amorphous materials. Oxalate-extractable iron and aluminum gave a useful indication of Bf horizon development in many soils, even if the parent materials were high in iron oxides. In one class of Gleysolic soils, however, the Bfg horizons were high in dithionite-extractable iron and low in oxalate-extractable iron. An accumulation of goethite was found in the Bfg horizon of some of these soils. In some other Gleysolic soils iron was depleted in the A horizon but there was no horizon of iron accumulation. Extractio...

1,875 citations


Cited by
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Journal ArticleDOI
01 Jan 1997-Nature
TL;DR: In this article, the authors explore the relationship between soil mineralogy and organic carbon along two natural gradients (i.e., soil-age and climate) in volcanic soil environments.
Abstract: A large source of uncertainty in present understanding of the global carbon cycle is the distribution and dynamics of the soil organic carbon reservoir. Most of the organic carbon in soils is degraded to inorganic forms slowly, on timescales from centuries to millennia1. Soil minerals are known to play a stabilizing role, but how spatial and temporal variation in soil mineralogy controls the quantity and turnover of long-residence-time organic carbon is not well known2. Here we use radiocarbon analyses to explore interactions between soil mineralogy and soil organic carbon along two natural gradients—of soil-age and of climate—in volcanic soil environments. During the first ∼150,000 years of soil development, the volcanic parent material weathered to metastable, non-crystalline minerals. Thereafter, the amount of non-crystalline minerals declined, and more stable crystalline minerals accumulated. Soil organic carbon content followed a similar trend, accumulating to a maximum after 150,000 years, and then decreasing by 50% over the next four million years. A positive relationship between non-crystalline minerals and organic carbon was also observed in soils through the climate gradient, indicating that the accumulation and subsequent loss of organic matter were largely driven by changes in the millennial scale cycling of mineral-stabilized carbon, rather than by changes in the amount of fast-cycling organic matter or in net primary productivity. Soil mineralogy is therefore important in determining the quantity of organic carbon stored in soil, its turnover time, and atmosphere–ecosystem carbon fluxes during long-term soil development; this conclusion should be generalizable at least to other humid environments.

1,308 citations

Journal ArticleDOI
TL;DR: In this paper, the development of a sequential extraction procedure for iron in modern and ancient sediments is presented, which recognizes seven operationally derived iron pools: (1) carbonate associated Fe (Fe carb ), including siderite and ankerite; (2) easily reducible oxides (Fe ox1 ), including ferrihydrite and lepidocrocite; and (3) reducible Oxides(Fe ox2 ), including goethite, hematite and akaganeite, (4) magnetite (Fe mag ); (5)

975 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present a review of sequential selective extraction techniques, with their advantages and disadvantages, and discuss the limits of sequential extraction procedures for the particular case of elements giving anionic species.
Abstract: Sequential selective extraction techniques are commonly used to fractionate the solid-phase forms of metals in soils. Many sequential extraction procedures have been developed, particularly for sediments or agricultural soils, and, despite numerous criticisms, they remain very useful. This article reviews the reagents used in the various schemes, with their advantages and disadvantages. The particular case of elements giving anionic species is also developed. Finally, there is discussion of the limits of sequential extraction procedures.

856 citations

Journal ArticleDOI
TL;DR: The availability of microbially reducible Fe(III) in surficial sediments demonstrates that microbial Fe( III) reduction can be important to organic matter decomposition and iron geochemistry, however, the overall extent of microbial Fe (III) reduction is governed by the inability of microorganisms to reduce most of the Fe(II) in the sediment.
Abstract: The distribution of Fe(III), its availability for microbial reduction, and factors controlling Fe(III) availability were investigated in sediments from a freshwater site in the Potomac River Estuary. Fe(III) reduction in sediments incubated under anaerobic conditions and depth profiles of oxalate-extractable Fe(III) indicated that Fe(III) reduction was limited to depths of 4 cm or less, with the most intense Fe(III) reduction in the top 1 cm. In incubations of the upper 4 cm of the sediments, Fe(III) reduction was as important as methane production as a pathway for anaerobic electron flow because of the high rates of Fe(III) reduction in the 0- to 0.5-cm interval. Most of the oxalate-extractable Fe(III) in the sediments was not reduced and persisted to a depth of at least 20 cm. The incomplete reduction was not the result of a lack of suitable electron donors. The oxalate-extractable Fe(III) that was preserved in the sediments was considered to be in a form other than amorphous Fe(III) oxyhydroxide, since synthetic amorphous Fe(III) oxyhydroxide, amorphous Fe(III) oxyhydroxide adsorbed onto clay, and amorphous Fe(III) oxyhydroxide saturated with adsorbed phosphate or fulvic acids were all readily reduced. Fe3O4 and the mixed Fe(III)-Fe(II) compound(s) that were produced during the reduction of amorphous Fe(III) oxyhydroxide in an enrichment culture were oxalate extractable but were not reduced, suggesting that mixed Fe(III)-Fe(II) compounds might account for the persistence of oxalate-extractable Fe(III) in the sediments. The availability of microbially reducible Fe(III) in surficial sediments demonstrates that microbial Fe(III) reduction can be important to organic matter decomposition and iron geochemistry. However, the overall extent of microbial Fe(III) reduction is governed by the inability of microorganisms to reduce most of the Fe(III) in the sediment.

674 citations

Journal ArticleDOI
TL;DR: The seasonal variation in oxidized and reduced pools of Mn, Fe and S, as well as the rates of SO42− reduction, were studied in a fine-grained sediment as mentioned in this paper.

634 citations