Soil Development under Continuous Agriculture at the Morrow Plots Experimental Fields from X-ray Diffraction Profile Modelling
| Autor: | Bruno Lanson, Eleanor Bakker, Fabien Hubert, Michelle M. Wander |
|---|---|
| Přispěvatelé: | Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Minéralogie et environnements, Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Financial support from INSU/EC2CO, ANR-10-LABX-0056,OSUG@2020,Innovative strategies for observing and modelling natural systems(2010) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Analytical chemistry Soil Science plant nutrition engineering.material 010502 geochemistry & geophysics 01 natural sciences mineral dissolution chemistry.chemical_compound Cation-exchange capacity Kaolinite Chlorite Dissolution ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences Earth-Surface Processes 2. Zero hunger clay mineralogy agricultural soil 04 agricultural and veterinary sciences [CHIM.CATA]Chemical Sciences/Catalysis 15. Life on land pedogenesis X-ray diffraction Pedogenesis chemistry X-ray crystallography Illite 040103 agronomy & agriculture engineering 0401 agriculture forestry and fisheries potassium uptake Clay minerals |
| Zdroj: | Soil Systems Volume 2 Issue 3 Soil Systems, 2018, 2 (3), pp.46. ⟨10.3390/soilsystems2030046⟩ Soil Systems, MDPI, 2018, 2 (3), pp.46. ⟨10.3390/soilsystems2030046⟩ |
| ISSN: | 2571-8789 |
| DOI: | 10.3390/soilsystems2030046 |
| Popis: | Impact of continuous cropping on clay mineralogy was assessed on a collection of unfertilized soil samples from the Morrow Plots experimental fields covering 110 years of long crop rotations. Evolution of mineralogy was quantitatively determined by fitting X-ray diffraction (XRD) patterns from four size fractions (50–2, 2–0.2, 0.2–0.05 and < 0.05 µm) of the surface horizon (0–20 cm). The mineralogy of the three clay subfractions (2–0.2 µm, 0.2–0.05 µm and < 0.05 µm) consists mainly of coexisting illite-smectite-chlorite whose compositions range from discrete illite (in the 2–0.2 µm subfraction) to discrete smectite (in the < 0.05 µm subfraction). Mixed layers of similar compositions were used to fit XRD data from all clay subfractions. With decreasing size fractions, both the size of the coherent scattering domains and the proportion of illite-rich mixed layers decrease, thus accounting for the higher cation exchange measured in the < 0.05 µm subfraction compared to other clay subfractions. The analysis of fine clay subfractions (< 0.2 µm or lower) provided key information and constraints to a complete and accurate description of the bulk < 2 µm fraction. Additional constraints derived from chemical treatments (K-saturation and heating) proved to be especially useful to propose a reliable structure model for these fine clay subfractions because of their weakly modulated diffraction signature. Mineralogy of all subfractions considered is essentially stable over the studied period (1904–2014), with the relative proportion of the different clay layer types (illite, smectite, kaolinite, chlorite) showing no significant evolution in the bulk < 2 µm fraction. A century of continuous cropping thus results essentially in an increase of fine clay particles (< 0.05 µm) and a decrease of the 0.2–0.05 µm subfraction, indicative of clay mineral dissolution and consistent with observed increase of cation exchange capacity with time. The relative proportion of the bulk < 2 µm fraction is nearly constant over the studied period, indicative of minimal export of clay phases. |
| Databáze: | OpenAIRE |
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