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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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| 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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| Oberson, Astrid; Jarosch, Klaus A.; Bosshard, Christine; Dubois, David; Frossard, Emmanuel; Hammelehle, Andreas; Mäder, Paul; Mayer, Jochen. |
| Organic and conventional cropping systems differ in the nature and amounts of nitrogen (N) inputs, which may affect efficiency and sustainability of N use. In the DOK (bio-Dynamic, bio-Organic, Konventionell) field experiment, organic and conventional cropping systems have been compared since 1978 at two fertilization levels. Nitrogen inputs via manure and/or mineral fertilizers, and N exports from plots with harvested products have throughout been recorded. For all treatments, N outputs with harvests have exceeded the inputs with fertilizers. Over the past years, symbiotic N2 fixation by soybean and clover grown in the trial has additionally been assessed, indicating average annual inputs of about 100 kg ha-1 yr-1 of N fixed from the atmosphere. Soil... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: "Organics" in general; Soil quality; Soil tillage. |
| Ano: 2018 |
URL: http://orgprints.org/34559/1/oberson-etal-2018ESA2018_FinalAbstractBook_p44.pdf |
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