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| Registros recuperados: 40 | |
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| Thomsen, Ingrid Kaag; Sørensen, Peter. |
| Soil tillage serves a number of purposes such as control of weeds, incorporation of crop residues and manures, and maintenance or improvement of soil mechanical properties, including seedbed preparations. As a side-effect, soil tillage may affect turnover of organic matter (OM) by changing the particle size and spatial distribution of crop and manure residues in soil and by increasing the intimacy of residue/soil contacts. By breaking soil structural elements, tillage may contribute further to N mineralization by exposing physically protected organic matter to microbial turnover. Therefore, adjusting the time, intensity and frequency of soil tillage operations may enable optimization of synchrony, defined as the matching through time of N availability and... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2004 |
URL: http://orgprints.org/4579/1/4579.PDF |
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| Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ambus, Per. |
| Organic arable farming faces challenges with low crop yields, partly due to inefficient use of green manure-derived nitrogen (N). Under current farming practices, green manure leys are often cut and mulched during the growing season with the associated risk of environmental N losses, leading to eutrophication and global warming. In this 3-month incubation experiment, we tested a new green manure management strategy as part of the ICROFS project HighCrop. With the new strategy, green manure leys are instead harvested and preserved until the following spring either as compost mixed with straw (grass-clover:straw, 4:1, w:w) or as silage of harvested ley biomass. In spring, these two green manure materials can then be used for targeted fertilization of spring... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover; Air and water emissions. |
| Ano: 2013 |
URL: http://orgprints.org/25941/19/25941a.pdf |
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| Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ma, Xiuzhi; Ambus, Per. |
| More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either as compost mixed with straw (grass-clover:straw, 4:1, w:w) or as silage of harvested ley biomass. Grass-clover compost or silage was soil-incorporated by either simulated ploughing (green manure placed at 15 cm depth) or harrowing (green manure mixed into the upper 5-cm soil horizon) in order to assess treatment effects on net release of plant-available N, nitrous oxide (N2O) fluxes, and soil respiration. Grass-clover silage provided the highest net N release with... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
| Ano: 2013 |
URL: http://orgprints.org/24960/7/24960.pdf |
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| De Notaris, Chiara; Rasmussen, Jim; Sørensen, Peter; Melander, Bo; Olesen, Jørgen E.. |
| Legume-based cover crop (CC) mixtures can increase nitrogen (N) availability in arable systems, reducing the need for external N inputs, as they retain soil N and fix atmospheric N2. However, they need sufficient biomass accumulation to influence soil N availability. Early establishment through undersowing can improve CC growth and plant N accumulation, but competition with the main crop should be minimized. This study aimed to investigate the effect of main crop inter-row spacing (12, 18, 24 cm), manure application (without, with) and CC undersowing (early, late, no cover crop) on N accumulation in a legume-based CC mixture and the residual N effect on the following crop. We conducted a field experiment in Denmark with spring wheat as main crop and spring... |
| Tipo: Journal paper |
Palavras-chave: Crop combinations and interactions; Farm nutrient management. |
| Ano: 2019 |
URL: http://orgprints.org/35015/1/De%20Notaris%202019_cover%20crop%26row%20spacing.pdf |
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| De Notaris, Chiara; Sørensen, Peter; Rasmussen, Jim; Olesen, Jørgen E.. |
| Increasing the row space of spring wheat from 12 to 24 cm, but maintaining the same seeding density, didn´t decrease its yield. On the other hand, it positively influenced the growth of the undersown catch crop, a mixture of red clover, white clover, rye grass and chicory. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop combinations and interactions; Nutrient turnover; Weed management; Farm nutrient management. |
| Ano: 2016 |
URL: http://orgprints.org/30876/1/Session%203-57-58.pdf |
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| Li, Xiaoxi; Sørensen, Peter; Olesen, Jørgen E.; Petersen, Søren O.. |
| Catch crops, especially leguminous catch crops, may increase crop nitrogen (N) supply and decrease environmental impacts in cropping systems, but they may also stimulate nitrous oxide (N2O) emissions following spring incorporation. In this 28-day laboratory incubation study, we examined the carbon (C) and N dynamics and N2O evolution after simulated incorporation of residues from three catch crop species into a loamy sand soil, with variable soil moisture (40, 50 or 60% water-filled pore space (WFPS)). The catch crops include two leguminous (red clover and winter vetch) and one non-leguminous species (ryegrass). Plant material was placed in a discrete layer surrounded by soil in which the nitrate (NO3-) pool was enriched with 15N to distinguish N2O derived... |
| Tipo: Journal paper |
Palavras-chave: Pasture and forage crops; Crop combinations and interactions; Nutrient turnover; Air and water emissions; Farm nutrient management. |
| Ano: 2015 |
URL: http://orgprints.org/30111/1/LXX3-2016%20SBB%20vol%2092%20p153-160.pdf |
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| De Notaris, Chiara; Rasmussen, Jim; Sørensen, Peter; Olesen, Jørgen E.. |
| Legume-based cover crops (CC) provide a wide range of ecosystem services, including nitrate leaching reduction, N fertilizer and soil C sequestration effects. However, the scarcity of information on belowground C and N increases the uncertainty on the magnitude of these effects. With the present study, we quantified soil C and N deposition from legume-based CC (two pure legumes and two mixtures) grown under field conditions, in Denmark. To do so, we labeled CC plants with 13C (CO2) and 15N (leaf-labeling) throughout their growing period, by following a frequent multiple-pulse labeling scheme. Then, we incubated labeled CC roots and soil to investigate C and N mineralization. Cover crops with red clover produced about 2.7 Mg ha-1 aboveground biomass, and... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2019 |
URL: http://orgprints.org/35017/1/CC%20lab_all_20190314.docx |
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| Noe, Egon; Alrøe, Hugo Fjelsted; Thorsøe, Martin H.; Sørensen, Peter; Melander, Bo; Olesen, Jørgen E.; Fog, Erik. |
| Research in organic cropping systems has identified basic principles for increasing the robustness and production level of organic arable systems. But even though farmers know these principles, they have not implemented them in practice. This paper aims to improve our understanding of this “knowledge gap” using the theory of knowledge asymmetries, and discusses the implications for research, extension and practice. The paper is based on interviews with 10 organic arable farms focused on how to understand the barriers from the perspective and context of the farming system. The findings show that some barriers are due to lack of knowledge of suggested actions, calling for more ordinary dissemination. But this cannot at all explain all the barriers. The... |
| Tipo: Journal paper |
Palavras-chave: Farming Systems; Knowledge management. |
| Ano: 2015 |
URL: http://orgprints.org/25416/7/25416.pdf |
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| Carter, Mette S.; Sørensen, Peter; Petersen, Søren O.; Ma, Xiuzhi; Ambus, Per. |
| More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either as compost mixed with straw or as silage of harvested ley biomass. Grass-clover compost or silage was soil-incorporated by either simulated ploughing (green manure placed at 15 cm depth) or harrowing (green manure mixed into the upper 5-cm soil horizon) in order to assess treatment effects on net release of plant-available N, nitrous oxide (N2O) fluxes, and soil respiration. Grass-clover silage provided the highest net N release with similar results for the two... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
| Ano: 2014 |
URL: http://orgprints.org/25158/7/25158.pdf |
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| De Notaris, Chiara; Rasmussen, Jim; Sørensen, Peter; Olesen, Jørgen E.. |
| Components of the field nitrogen (N) balance (input and surplus) are often used to predict nitrate leaching from agricultural lands. However, management factors, such as use of catch crops, greatly affect the actual loss and are a key to reduce N leaching. The present study is based on the 4th cycle of a long-term crop rotation experiment in Denmark, and it aims to quantify, from a crop rotation perspective, the influence on N leaching from N input and surplus or management factors. The experiment included three cropping systems (two organic and one conventional) with or without use of animal manure and catch crops. N leaching was calculated from measurements of nitrate in soil water sampled with ceramic suction cups installed at 1 m depth in all plots. At... |
| Tipo: Journal paper |
Palavras-chave: Air and water emissions; Farm nutrient management. |
| Ano: 2018 |
URL: http://orgprints.org/32665/1/De%20Notaris%202018_N%20leaching.pdf |
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| Hu, Teng; Sørensen, Peter; Wahlström, E.M.; Chirinda, Ngonidzashe; Sharif, Behzad; Li, Xiaoxi; Olesen, Jørgen E.. |
| Reliable information on belowground plant biomass is essential to estimate belowground carbon inputs to soils. Estimations of belowground plant biomass are often based on a fixed allometric relationship of plant biomass between aboveground and belowground parts. However, environmental and management factors may affect this allometric relationship making such estimates uncertain and biased. Therefore, we aimed to explore how root biomass for typical cereal crops, catch crops and weeds could most reliably be estimated. Published and unpublished data on aboveground and root biomass (corrected to 0–25 cm depth) of cereal crops (wheat and barley), catch crops and weeds were collected from studies in Denmark. Leave one out cross validation was used to determine... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2018 |
URL: http://orgprints.org/32991/1/Paper%20Published%20Root%20Estimation.pdf |
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| Registros recuperados: 40 | |
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