| Registro completo |
| Provedor de dados: |
Organic Eprints
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| País: |
Germany
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| Título: |
Nitrogen fixation and transfer in grassclover leys under organic and conventional cropping systems
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| Autores: |
Oberson, A.
Frossard, E.
Bühlmann, C.
Mayer, J.
Mäder, P.
Lüscher, A.
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| Data: |
2013-03
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| Ano: |
2013
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| Palavras-chave: |
Nutrient turnover
Crop husbandry
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| Resumo: |
Background and aim Symbiotic dinitrogen (N2) fixation is the most important external N source in organic systems. Our objective was to compare symbiotic N2 fixation of clover grown in organically and conventionally cropped grass-clover leys, while taking into account nutrient supply gradients. Methods We studied leys of a 30-year-old field experiment over 2 years in order to compare organic and conventional systems at two fertilization levels. Using 15N natural abundance methods, we determined the proportion of N derived from the atmosphere (PNdfa), the amount of Ndfa (ANdfa), and the transfer of clover N to grasses for both red clover (Trifolium pratense L.) and white clover (Trifolium repens L.). Results In all treatments and both years, PNdfa was high (83 to 91 %), indicating that the N2 fixation process is not constrained, even not in the strongly nutrient deficient non-fertilized control treatment. Annual ANdfa in harvested clover biomass ranged from 6 to 16 gN m−2. At typical fertilizer input levels, lower sward yield in organic than those in conventional treatments had no effect on ANdfa because of organic treatments had greater clover proportions. In two-year-old leys, on average, 51 % of N taken up by grasses was transferred from clover. Conclusion Both, organically and conventionally cropped grass-clover leys profited from symbiotic N2 fixation, with high PNdfa, and important transfer of clover N to grasses, provided sufficient potassiumand phosphorus-availability to sustain clover biomass production.
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| Tipo: |
Journal paper
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| Identificador: |
http://orgprints.org/23228/1/Oberson-etal-2013-PlantansSoil-onlinefirst.pdf
Oberson, A.; Frossard, E.; Bühlmann, C.; Mayer, J.; Mäder, P. and Lüscher, A. (2013) Nitrogen fixation and transfer in grassclover leys under organic and conventional cropping systems. Plant and Soil, (online), - .
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| Relação: |
http://orgprints.org/23228/
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| Formato: |
application/pdf
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