61 research outputs found
A 300-year record of sedimentation in a small tilled catena in Hungary based on δ13C, δ15N, and C/N distribution
Purpose Soil erosion is one of the most serious hazards that endanger sustainable food production. Moreover, it has marked effects on soil organic carbon (SOC) with direct links to global warming. At the same time, soil organic matter (SOM) changes in composition and space could influence these processes. The aim of this study was to predict soil erosion and sedimentation volume and dynamics on a typical hilly cropland area of Hungary due to forest clearance in the early eighteenth century. Materials and methods Horizontal soil samples were taken along two parallel intensively cultivated complex convex-concave slopes from the eroded upper parts at mid-slope positions and from sedimentation in toe-slopes. Samples were measured for SOC, total nitrogen (TN) content, and SOMcompounds (δ13C, δ15N, and photometric indexes). They were compared to the horizons of an in situ non-eroded profile under continuous forest. On the depositional profile cores, soil depth prior to sedimentation was calculated by the determination of sediment thickness. Results and discussion Peaks of SOC in the sedimentation profiles indicated thicker initial profiles, while peaks in C/N ratio and δ13C distribution showed the original surface to be ~ 20 cm lower. Peaks of SOC were presumed to be the results of deposition of SOC-enriched soil from the upper slope transported by selective erosion of finer particles (silts and clays). Therefore, changes in δ13C values due to tillage and delivery would fingerprint the original surface much better under the sedimentation scenario than SOC content. Distribution of δ13C also suggests that the main sedimentation phase occurred immediately after forest clearance and before the start of intense cultivation with maize. Conclusions This highlights the role of relief in sheet erosion intensity compared to intensive cultivation. Patterns of δ13C indicate the original soil surface, even in profiles deposited as sediment centuries ago. The δ13C and C/N decrease in buried in situ profiles had the same tendency as recent forest soil, indicating constant SOM quality distribution after burial. Accordingly, microbiological activity, root uptake, and metabolism have not been effective enough to modify initial soil properties
The Role of the Humic Substances in the Fractioning of Heavy Metals in Rodrigo de Freitas Lagoon, Rio de Janeiro - Brazil
Pesticide sorption in typical Central European soils evaluated using a photometric microplate assay based on acetylcholinesterase inhibition
Mineralisation and humification of plant matter in soil samples as a tool in the testing of soil quality
Spectroscopic Characterization of Humic Substances Isolated from Sediment of an Area of Sugarcane Cultivation
Decomposition rate of Quercus rotundifolia leaves in an evergreen oak forest of the Duero Basin (Province of Zamora, Spain)
Dynamics of Newly Formed Humic Acid and Fulvic Acid in Aggregates After Addition of the 14C-Labelled Wheat Straw in a Typic Hapludoll of Northeast China
Soil Organic Carbon Molecular Properties: Effects of Time Since Reclamation in a Minesoil Chronosequence
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