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| Bosshard, Christine; Sorensen, Peter; Frossard, Emmanuel; Mayer, Jochen; Mäder, Paul; Nanzer, Simone; Oberson, Astrid. |
| Nitrogen (N) utilisation by crops has to be improved to minimize losses to the environment. We investigated N use efficiency of animal manure and mineral fertiliser and fate of fertiliser N not taken up by crops in a bio-organic (BIOORG) and a conventional (CONMIN) cropping system of a long-term experiment over three vegetation periods (wheat-soybean-maize). Microplots received a single application of 15N-labelled slurries or mineral fertiliser. At the end of each vegetation period we tested whether higher microbial activity and biomass in BIOORG than CONMIN soils and lower long-term N input level in BIOORG affected use efficiency and fate of fertiliser N not taken up by crops. In total 41%, 15% and 50% of 15N applied as urine, faeces and mineral... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover. |
| Ano: 2009 |
URL: http://orgprints.org/14392/1/Bosshard_14392.pdf |
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| Nanzer, Simone; Frossard, Emmanuel; Bosshard, Christine; Dubois, Davie; Mäder, Paul; Oberson, Astrid. |
| 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,... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Farm nutrient management. |
| Ano: 2009 |
URL: http://orgprints.org/14124/1/Nanzer_14124.pdf |
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