The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform

Charlotte Kjaergaard - One of the best experts on this subject based on the ideXlab platform.

  • recovering decomposing plant residues from the particulate soil organic matter fraction size versus Density Separation
    Biology and Fertility of Soils, 2001
    Co-Authors: Jakob Magid, Charlotte Kjaergaard
    Abstract:

    A detailed size Separation of particulate organic matter (POM) from soils amended with straw from Hordeum vulgare or Vicia sativa revealed that the loss of C during the first 56 days of incubation mainly occurred from particles >2,000 μm, without a concomitant reduction in the size of these large particles. Preliminary studies of POM from non-amended soil had shown that the stable heavy (>1.4 g cm–3) POM fraction was mainly (>80%) composed of particles 80%). Therefore we decided to compare the POM 400 μm. There was a very close relationship between POM>400 μm and POM <1.4 g cm–3 with regard to amounts of C and N, as well as the appearance of these fractions under the microscope. Similarly there was a close relationship between changes in the C content of the POM fractions and the CO2 respired, and this was also the case when comparing changes in POM-N with net N mineralization. This indicated that the biological activity during decomposition was actually localized in the POM. Due to the lighter workload and lower expenditure for reagents in connection with size Separation of POM, we recommend the size Separation procedure in connection with studies of residue decomposition in arable systems.

  • Recovering decomposing plant residues from the particulate soil organic matter fraction: size versus Density Separation
    Biology and Fertility of Soils, 2001
    Co-Authors: Jakob Magid, Charlotte Kjaergaard
    Abstract:

    A detailed size Separation of particulate organic matter (POM) from soils amended with straw from Hordeum vulgare or Vicia sativa revealed that the loss of C during the first 56 days of incubation mainly occurred from particles >2,000 μm, without a concomitant reduction in the size of these large particles. Preliminary studies of POM from non-amended soil had shown that the stable heavy (>1.4 g cm–3) POM fraction was mainly (>80%) composed of particles 80%). Therefore we decided to compare the POM 400 μm. There was a very close relationship between POM>400 μm and POM

Rota Wagai - One of the best experts on this subject based on the ideXlab platform.

  • climate and parent material controls on organic matter storage in surface soils a three pool Density Separation approach
    Geoderma, 2008
    Co-Authors: Rota Wagai, Lawrence M Mayer, Kanehiro Kitayama, Heike Knicker
    Abstract:

    article Physically- and biochemically-distinct fractions of soil organic matter (SOM) can be separated by Density to yield: (i) low-Density plant detritus fraction easily separable from soil minerals (f-LF), (ii) low-Density materials strongly associated with minerals (m-LF), and (iii) high-Density fraction (HF) rich in microbially- processed organic matter strongly associated with minerals. The factors controlling the pool size and chemistry in these fractions, especially those in m-LF, are unclear. We examined the influence of climate and parent material on SOM in these fractions using two sets of forest soils (0-10 cm mineral horizon) developed from contrasting parent materials (metasedimentary vs. ultrabasic igneous rock) along an altitudinal gradient in Mt. Kinabalu, Borneo. From 700 m to upper altitudes (1700, 2700 m), where mean annual temperature decreases from 24 to 12 °C with roughly constant rainfall, surface soil C stocks on both parent

Jakob Magid - One of the best experts on this subject based on the ideXlab platform.

  • recovering decomposing plant residues from the particulate soil organic matter fraction size versus Density Separation
    Biology and Fertility of Soils, 2001
    Co-Authors: Jakob Magid, Charlotte Kjaergaard
    Abstract:

    A detailed size Separation of particulate organic matter (POM) from soils amended with straw from Hordeum vulgare or Vicia sativa revealed that the loss of C during the first 56 days of incubation mainly occurred from particles >2,000 μm, without a concomitant reduction in the size of these large particles. Preliminary studies of POM from non-amended soil had shown that the stable heavy (>1.4 g cm–3) POM fraction was mainly (>80%) composed of particles 80%). Therefore we decided to compare the POM 400 μm. There was a very close relationship between POM>400 μm and POM <1.4 g cm–3 with regard to amounts of C and N, as well as the appearance of these fractions under the microscope. Similarly there was a close relationship between changes in the C content of the POM fractions and the CO2 respired, and this was also the case when comparing changes in POM-N with net N mineralization. This indicated that the biological activity during decomposition was actually localized in the POM. Due to the lighter workload and lower expenditure for reagents in connection with size Separation of POM, we recommend the size Separation procedure in connection with studies of residue decomposition in arable systems.

  • Recovering decomposing plant residues from the particulate soil organic matter fraction: size versus Density Separation
    Biology and Fertility of Soils, 2001
    Co-Authors: Jakob Magid, Charlotte Kjaergaard
    Abstract:

    A detailed size Separation of particulate organic matter (POM) from soils amended with straw from Hordeum vulgare or Vicia sativa revealed that the loss of C during the first 56 days of incubation mainly occurred from particles >2,000 μm, without a concomitant reduction in the size of these large particles. Preliminary studies of POM from non-amended soil had shown that the stable heavy (>1.4 g cm–3) POM fraction was mainly (>80%) composed of particles 80%). Therefore we decided to compare the POM 400 μm. There was a very close relationship between POM>400 μm and POM

Heike Knicker - One of the best experts on this subject based on the ideXlab platform.

  • climate and parent material controls on organic matter storage in surface soils a three pool Density Separation approach
    Geoderma, 2008
    Co-Authors: Rota Wagai, Lawrence M Mayer, Kanehiro Kitayama, Heike Knicker
    Abstract:

    article Physically- and biochemically-distinct fractions of soil organic matter (SOM) can be separated by Density to yield: (i) low-Density plant detritus fraction easily separable from soil minerals (f-LF), (ii) low-Density materials strongly associated with minerals (m-LF), and (iii) high-Density fraction (HF) rich in microbially- processed organic matter strongly associated with minerals. The factors controlling the pool size and chemistry in these fractions, especially those in m-LF, are unclear. We examined the influence of climate and parent material on SOM in these fractions using two sets of forest soils (0-10 cm mineral horizon) developed from contrasting parent materials (metasedimentary vs. ultrabasic igneous rock) along an altitudinal gradient in Mt. Kinabalu, Borneo. From 700 m to upper altitudes (1700, 2700 m), where mean annual temperature decreases from 24 to 12 °C with roughly constant rainfall, surface soil C stocks on both parent

Michael F Hochella - One of the best experts on this subject based on the ideXlab platform.

  • the role of nanominerals and mineral nanoparticles in the transport of toxic trace metals field flow fractionation and analytical tem analyses after nanoparticle isolation and Density Separation
    Geochimica et Cosmochimica Acta, 2013
    Co-Authors: Kelly L Plathe, Frank Von Der Kammer, Martin Hassellov, Johnnie N Moore, Mitsuhiro Murayama, Thilo Hofmann, Michael F Hochella
    Abstract:

    Nanominerals and mineral nanoparticles from a mining-contaminated river system were examined to determine their potential to co-transport toxic trace metals. A recent large-scale dam removal project on the Clark Fork River in western Montana (USA) has released reservoir and upstream sediments contaminated with toxic trace metals (Pb, As, Cu and Zn), which had accumulated there as a consequence of more than a century and a half of mining activity proximal to the river's headwaters near the cities of Butte and Anaconda. To isolate the high-Density nanoparticle fractions from riverbed and bank sediments, a Density Separation with sodium polytungstate (2.8 g/cm(3)) was employed prior to a standard nanoparticle extraction procedure. The stable, dispersed nanoparticulate fraction was then analyzed by analytical transmission electron microscopy (aTEM) and flow field-flow fractionation (FlFFF) coupled to both multi-angle laser light scattering (MALLS) and high-resolution, inductively coupled plasma mass spectrometry (HR-ICPMS). FlFFF analysis revealed a size distribution in the nano range and that the elution profiles of the trace metals matched most closely to that for Fe and Ti. aTEM confirmed these results as the majority of the Fe and Ti oxides analyzed were associated with one or more of the trace metals of interest. The main mineral phases hosting trace metals are goethite, ferrihydrite and brookite. This demonstrates that they are likely playing a significant role in dictating the transport and distribution of trace metals in this river system, which could affect the bioavailability and toxicity of these metals. (C) 2012 Elsevier Ltd. All rights reserved.