The Experts below are selected from a list of 153 Experts worldwide ranked by ideXlab platform

Philippe Rochette - One of the best experts on this subject based on the ideXlab platform.

  • fate of carbon and nitrogen from animal manure and crop residues in wet and Cold Soils
    Soil Biology & Biochemistry, 2002
    Co-Authors: Martin H. Chantigny, Denis A. Angers, Philippe Rochette
    Abstract:

    Abstract Organic matter transformations take place in snow-covered Soils during winter but in ways still poorly understood. Given the generally high soil water content and possible formation of ice layers during this period, anaerobic zones could develop and have determinant effects on soil C and N dynamics. The fate of C and N under wet and Cold conditions was monitored in a sandy loam and a clay soil which were either unamended (control) or amended with cattle manure, pig slurry, maize or alfalfa residues. Soil samples were incubated for 84 d during winter at constant water potential (−6 kPa) in sealed containers laid on the floor of an unheated greenhouse. The containers were covered with fibre glass wool to simulate a snow cover. The O2, CO2 and N2O concentrations were periodically monitored in the headspace of the containers, whereas K2SO4-extractable C, KCl-extractable NO3− and NH4+, and volatile fatty acids were quantified in soil sub-samples. Despite the low soil temperature (average of 1 °C), O2 consumption and CO2 production rates were significantly (P

  • Fate of carbon and nitrogen from animal manure and crop residues in wet and Cold Soils
    Soil Biology and Biochemistry, 2002
    Co-Authors: Martin H. Chantigny, Denis A. Angers, Philippe Rochette
    Abstract:

    Organic matter transformations take place in snow-covered Soils during winter but in ways still poorly understood. Given the generally high soil water content and possible formation of ice layers during this period, anaerobic zones could develop and have determinant effects on soil C and N dynamics. The fate of C and N under wet and Cold conditions was monitored in a sandy loam and a clay soil which were either unamended (control) or amended with cattle manure, pig slurry, maize or alfalfa residues. Soil samples were incubated for 84 d during winter at constant water potential (-6 kPa) in sealed containers laid on the floor of an unheated greenhouse. The containers were covered with fibre glass wool to simulate a snow cover. The O2, CO2and N2O concentrations were periodically monitored in the headspace of the containers, whereas K2SO4-extractable C, KCl-extractable NO3-, and NH4+, and volatile fatty acids were quantified in soil sub-samples. Despite the low soil temperature (average of 1°C), O2consumption and CO2production rates were significantly (P < 0.05) increased by the amendments for the first 29 d of incubation. After 29 d, the O2concentration fell below 6% and CO2production rate decreased in all amended Soils. We assumed that after 29 d aerobic respiration was replaced with fermentation processes in amended Soils as indicated by respiratory quotients generally larger than 2, and by the progressive accumulation of volatile fatty acids. As O2was consumed in sealed containers, nitrification decreased whereas ammonification continued and N2O production increased. As a result, soil NH4+content increased whereas NO3-content was progressively depleted. After complete exhaustion of NO3-, the accumulated N2O disappeared and was probably reduced to N2. All measured parameters indicated that pig slurry and alfalfa stimulated soil microbial activities more than cattle manure and maize residues and these differences were partly related to the lignin-to-N ratio of the various amendments. Our data indicated that (i) significant C and N transformations occurred during winter in wet and Cold Soils amended with organic residues, (ii) under these conditions C and N dynamics were strongly influenced by O2availability, and (iii) the rates at which C and N transformations occurred were partly determined by both C degradability and N availability of the organic amendments. Crown Copyright © 2002 Published by Elsevier Science Ltd. All rights reserved.

Jacek Oleksyn - One of the best experts on this subject based on the ideXlab platform.

  • scots pine fine roots adjust along a 2000 km latitudinal climatic gradient
    New Phytologist, 2016
    Co-Authors: Marcin Zadworny, Luke M Mccormack, Joanna Mucha, Peter B Reich, Jacek Oleksyn
    Abstract:

    Summary Patterns of plant biomass allocation and functional adjustments along climatic gradients are poorly understood, particularly belowground. Generally, low temperatures suppress nutrient release and uptake, and forests under such conditions have a greater proportion of their biomass in roots. However, it is not clear whether ‘more roots’ means better capacity to acquire soil resources. Herein we quantified patterns of fine-root anatomy and their biomass distribution across Scots pine (Pinus sylvestris) populations both along a 2000-km latitudinal gradient and within a common garden experiment with a similar range of populations. We found that with decreasing mean temperature, a greater percentage of Scots pine root biomass was allocated to roots with higher potential absorptive capacity. Similar results were seen in the common experimental site, where Cold-adapted populations produced roots with greater absorptive capacity than populations originating from warmer climates. These results demonstrate that plants growing in or originated from Colder climates have more acquisitive roots, a trait that is likely adaptive in the face of the low resource availability typical of Cold Soils.

James B Miller - One of the best experts on this subject based on the ideXlab platform.

Martin H. Chantigny - One of the best experts on this subject based on the ideXlab platform.

  • fate of carbon and nitrogen from animal manure and crop residues in wet and Cold Soils
    Soil Biology & Biochemistry, 2002
    Co-Authors: Martin H. Chantigny, Denis A. Angers, Philippe Rochette
    Abstract:

    Abstract Organic matter transformations take place in snow-covered Soils during winter but in ways still poorly understood. Given the generally high soil water content and possible formation of ice layers during this period, anaerobic zones could develop and have determinant effects on soil C and N dynamics. The fate of C and N under wet and Cold conditions was monitored in a sandy loam and a clay soil which were either unamended (control) or amended with cattle manure, pig slurry, maize or alfalfa residues. Soil samples were incubated for 84 d during winter at constant water potential (−6 kPa) in sealed containers laid on the floor of an unheated greenhouse. The containers were covered with fibre glass wool to simulate a snow cover. The O2, CO2 and N2O concentrations were periodically monitored in the headspace of the containers, whereas K2SO4-extractable C, KCl-extractable NO3− and NH4+, and volatile fatty acids were quantified in soil sub-samples. Despite the low soil temperature (average of 1 °C), O2 consumption and CO2 production rates were significantly (P

  • Fate of carbon and nitrogen from animal manure and crop residues in wet and Cold Soils
    Soil Biology and Biochemistry, 2002
    Co-Authors: Martin H. Chantigny, Denis A. Angers, Philippe Rochette
    Abstract:

    Organic matter transformations take place in snow-covered Soils during winter but in ways still poorly understood. Given the generally high soil water content and possible formation of ice layers during this period, anaerobic zones could develop and have determinant effects on soil C and N dynamics. The fate of C and N under wet and Cold conditions was monitored in a sandy loam and a clay soil which were either unamended (control) or amended with cattle manure, pig slurry, maize or alfalfa residues. Soil samples were incubated for 84 d during winter at constant water potential (-6 kPa) in sealed containers laid on the floor of an unheated greenhouse. The containers were covered with fibre glass wool to simulate a snow cover. The O2, CO2and N2O concentrations were periodically monitored in the headspace of the containers, whereas K2SO4-extractable C, KCl-extractable NO3-, and NH4+, and volatile fatty acids were quantified in soil sub-samples. Despite the low soil temperature (average of 1°C), O2consumption and CO2production rates were significantly (P < 0.05) increased by the amendments for the first 29 d of incubation. After 29 d, the O2concentration fell below 6% and CO2production rate decreased in all amended Soils. We assumed that after 29 d aerobic respiration was replaced with fermentation processes in amended Soils as indicated by respiratory quotients generally larger than 2, and by the progressive accumulation of volatile fatty acids. As O2was consumed in sealed containers, nitrification decreased whereas ammonification continued and N2O production increased. As a result, soil NH4+content increased whereas NO3-content was progressively depleted. After complete exhaustion of NO3-, the accumulated N2O disappeared and was probably reduced to N2. All measured parameters indicated that pig slurry and alfalfa stimulated soil microbial activities more than cattle manure and maize residues and these differences were partly related to the lignin-to-N ratio of the various amendments. Our data indicated that (i) significant C and N transformations occurred during winter in wet and Cold Soils amended with organic residues, (ii) under these conditions C and N dynamics were strongly influenced by O2availability, and (iii) the rates at which C and N transformations occurred were partly determined by both C degradability and N availability of the organic amendments. Crown Copyright © 2002 Published by Elsevier Science Ltd. All rights reserved.

Nancy W Callan - One of the best experts on this subject based on the ideXlab platform.