| Autor: |
Nanzer, Simone, Frossard, Emmanuel, Bosshard, Christine, Dubois, Davie, Mäder, Paul, Oberson, Astrid |
| Jazyk: |
němčina |
| Rok vydání: |
2009 |
| Předmět: |
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| Popis: |
In organic cropping systems nitrogen (N) often limits agricultural production. N2 fixing crops present an important option to improve N supply and to maintain soil fertility. We investigated N2 fixation of soybean in conventional and organic cropping systems. The study was carried out on a long term field experiment, characterized by unequal fertilization rates and soil microbial activity for the different systems. We assessed the proportion of N derived from atmosphere (Ndfa) and the total amount of N symbiotically fixed (Nfix) using the 15N natural abundance method. Ndfa for soybean was low, ranging from 24 to 54%. The lowest Ndfa was reported for the exclusively mineral fertilized, and the highest for the bio-organic cropping system. However, there were no differences between the farming systems in total amount of N symbiotically fixed. Irrespective of the cropping system, N withdrawal by harvest was higher than N input by N2 fixation, meaning that soil N stock was not preserved. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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