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| Hammelehle, Andreas; Oberson, Astrid; Lüscher, Andreas; Mäder, Paul; Mayer, Jochen. |
| Aims Belowground legume nitrogen (N) composed of roots and rhizodeposition is an important N input to soils, but published data of belowground N vary broadly, probably due to extrapolation from short-term experiments and dissimilar growing conditions. We quantified belowground N inputs of red clover (Trifolium pratense L.) during two consecutive years in a clover-grass sward along a soil nutrient availability gradient. Methods We established a red clover-perennial ryegrass (Lolium perenne L.) model sward in microplots located in field plots of the DOK experiment, which has a 33-year history of organic and conventional cropping, resulting in a soil nutrient availability gradient. Four treatments were examined: the zero fertilisation control, bio-organic... |
| Tipo: Journal paper |
Palavras-chave: Soil quality; Composting and manuring. |
| Ano: 2018 |
URL: http://orgprints.org/34924/1/hammelehle-etal-2018-PlantSoil-Vol425-Issue1-2-p507-525.pdf |
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| Mayer, Jochen; Oberson, Astrid; Lüscher, Andreas; Frossard, Emmanuel; Hammelehle, Andreas. |
| We investigated the effect of organic versus conventional cropping systems on the below ground nitrogen inputs of Trifolium pratense L., its transfer to corresponding grass and the fate in the soil organic matter in the clover-grass ley of the DOK long term experiment, Switzerland. BGN tended to be largest in conventional and organic treatments with standard fertilisation and decreased with lower fertilisation intensity. The largest amount of clover N transferred to grass was observed in the minerally fertilised conventional treatment. Clover N derived from rhizodeposition was rapidly stabilised in all treatments to clay rich fractions and thus clover N will have a relatively low direct N contribution to subsequent nonlegumes. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover. |
| Ano: 2014 |
URL: http://orgprints.org/24030/1/24030_MM.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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| Mayer, Jochen; Jarosch, KA.; Hammelehle, Andreas; Dubois, David; Gunst, Lucie; Bosshard, C.; Frossard, Emmanuel; Mäder, Paul; Oberson, Astrid. |
| N-balances over 35 years from the DOK trial are presented and combined with Nstock changes in DOK treatments on different fertilisation levels. Results strongly indicate an N efficiency-sustainability dilemma: DOK treatments with a high nitrogen use efficiency (NUE) lose more soil stock N than those with a lower NUE but higher N losses from the system. The biodynamic system showed little advantage in terms of soil N stocks sustainability while the solely mineral fertilised conventional treatment had highest NUE across all inputs including soil N change. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Biodiversity and ecosystem services; Farm nutrient management. |
| Ano: 2017 |
URL: http://orgprints.org/31925/1/Stickstoffbilanzen%20in%20biologischen%20und%20konventionellen.pdf |
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| Hammelehle, Andreas; Müller, Torsten; Oberson, Astrid; Mäder, Paul; Mayer, Jochen. |
| Symbiotic N2 fixation (Nfix) and N-balance was determined from organic and conven-tional grown soybean in the DOK experiment (Switzerland). Nfix was calculated i) based solely on soybean aboveground N (AGN) and ii) additionally taking into account belowground N (BGN), comprising N in physical roots and N rhizodeposition. Nfix was averagely two times higher considering AGN and BGN, ranging from 22 g N m-2 (conventional manure) to 37 g N m-2 (conventional mineral). N balances were positive in all treatments, but with 2 – 7 g N m-2 based on AGN solely comparatively small. These values were exceeded fourfold when considering BGN ranging from 13 g N m-2 (conventional manure) to 21 g N m-2 (organic and conventional mineral). |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop husbandry; Soil. |
| Ano: 2013 |
URL: http://orgprints.org/21426/1/21426_hammelehle.pdf |
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| Mayer, Jochen; Hirte, Juliane; Oberson, Astrid; Lüscher, Andreas; Frossard, Emmanuel; Mäder, Paul; Hammelehle, Andreas. |
| We investigated nitrogen and carbon below ground inputs of soybean, clover-grass and maize and management effects of biological and conventional systems in the DOK long term experiment. We found for soybean increasing below ground C and N inputs with decreasing fertilization intensity whereas those effects were small for clover-grass. Below ground nitrogen inputs of red clover could be estimated by above ground N multiplied with a factor of 0.5. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Soil quality Cereals; Pulses and oilseeds Nutrient turnover. |
| Ano: 2015 |
URL: http://orgprints.org/27229/1/27229_mayer.pdf |
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