Effect of fertilization on respiration from different sources in a sandy soil of an agricultural long-term experiment |
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| Authors: | Felix Heitkamp Nadine Jäger Heinz Flessa Joachim Raupp Bernard Ludwig |
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| Affiliation: | 1. Department of Environmental Chemistry , University of Kassel , Witzenhausen , Germany;2. Landscape Ecology , Institute of Geography, University of G?ttingen , Germany fheitka@uni-goettingen.de;4. Soil Science of Temperate and Boreal Ecosystems , Büsgen-Institute, University of G?ttingen , Germany;5. Soil Science of Temperate and Boreal Ecosystems , Büsgen-Institute, University of G?ttingen , Germany;6. Institute of Agricultural Climate Research , Johann Heinrich von Thünen-Institute , Braunschweig , Germany;7. Institute for Biodynamic Research , Darmstadt , Germany;8. Department of Environmental Chemistry , University of Kassel , Witzenhausen , Germany |
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| Abstract: | Annual changes in stocks of soil organic carbon may be detected by measurement of heterotrophic respiration, but field studies of heterotrophic respiration in long-term fertilization experiments on sandy soils are scarce. Our objectives were to: (1)investigate the influence of fertilizer type on mineralization of soil organic carbon and crop residue, and (2) show how fertilization treatments affect the annual C balance (net ecosystem carbon balance, NECB; negative values indicate a CO2-source) in the sandy soil of the Darmstadt experiment. Treatments were long-term mineral fertilization with cereal straw incorporation (MSI) and application of rotted farmyard manure (FYM), both treatments receiving 14 g N m?2 year?1. This study used δ13C natural abundance after introduction of a C4 crop to distinguish between different sources of respiration. Mineralization derived from C3 sources was similar for MSI and FYM treatments (～270 g C m?2 year?1). The rate of residue mineralization in MSI treatments was higher, resulting in a mineralization of 49 and 37% of initial residue C in the soil of MSI and FYM treatments, respectively. The NECB (g C m?2 year?1) indicated the MSI treatment (approximately ?190) as a stronger source compared with the FYM treatment (～?30). |
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| Keywords: | stable isotopes farmyard manure mineralization mineral fertilization carbon balance |
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