Description: Das Projekt "Lipids in soils: Soils as sources and sinks of CO2" wird vom Umweltbundesamt gefördert und von Universität Zürich, Geographisches Institut durchgeführt. Lipids represent a highly refractory fraction of soil organic matter. Investigations on lipids applying modern structural and isotopic methods, are still scarce. Replacing isotopically light C3-plants (e. g. rye) with heavier C4-plants (e. g. corn) produces naturally labeled biomass, allowing to asses turnover time. At the same time, these plants, and coexisting bacteria and fungi, carry their individual structural fingerprint, which can be used for identification. In this study we simultaneously apply isotopic and structural analysis to obtain information on sources and turnover times (delta13C) of lipids in agricultural soils on a molecular level. Plant and soil samples from the plowed horizon of experimental agricultural plots Ewiger Roggenbau at Halle/Saale, Rotthalmuenster near Passau, Boigneville and Versailles are subject of this study. Samples were taken at different times after introduction of a corn monoculture, and from a reference site kept under rye or wheat, depending on the locality. First results show that plant lipid distribution pattern of lipids like n-alkanes or carboxylic acids vary between different cropped soils and between the different crop plants. However, there are significant variations between plant parts like shoots/leaves and roots. These differences can be expressed in molecular ratios like n-C24/n-C22 within carboxylic acid fraction that coincide with the ratio n-C23/n-C21 within the n-alkane fraction. High values of these ratios can be observed in C4-cropped soils while simultaneously C3-cropped soils of the same location show lower ratios. The bulk isotopy (delta13C) shows for shoots, leaves and roots similar results of -12,5‰ for corn plants. In contrast compound specific signature of predominant long chain n-alkanes like n-C29 and n-C31 vary between -18‰ for fresh shoots and leaves and -30‰ for alterated shoots and roots as well as fresh roots of the same plants. Associated soils contain a mixture of above and subsurface plant lipids. Summarizing, lipid and isotopic markers can be used to analyze input and turnover of plant biomass into soils on a molecular level.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Organische Leuchtdiode ? Alkan ? Roggen ? Weizen ? Getreide ? Mais ? Zierpflanze ? Biogeochemie ? Zürich ? Beleuchtung ? Carbonsäure ? Humus ? Kulturpflanze ? Lipid ? Pflanzensamen ? Tracer ? Kohlendioxid ? Laubblatt ? Licht ? Pflanzenwurzel ? Bakterien ? Staude ? Technosol ? Ackerboden ? Unterboden ? Saale ? Monokultur ? Pilz ? Analyse ? Boden ? Phytomasse ? Bodenwert ? Bodenprobe ? Stoffgemisch ? Studie ? Klimawandel ? Änderung ? Biomasse ? Landwirtschaft ? Versuchsanlage ? Genetischer Fingerabdruck ? soil lipid ? Halle ? Laub ? Flächensanierung ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2000-11-01 - 2006-10-31
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