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Registros recuperados: 16
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15Nitrogen transfer from legumes to neighbouring plants in multi-species grassland Organic Eprints
Pirhofer-Walzl, K.; Høgh-Jensen, H.; Rasmussen, J.; Rasmussen, J.; Søegaard, K.; Eriksen, J..
This study investigates the N transfer from legumes to neighbouring plants, grasses, legumes and herbs in a temperate grassland. In a field experiment white clover (Trifolium repens), red clover (Trifolium pratense) and lucerne (Medicago sativa) were leaf-labelled with 15N enriched urea. The 15N tracer was measured in above-ground plant tissue of eight neighbouring plants in two subsequent harvests in 2008. The three legumes donated 15N to all neighbouring plants, of which grasses, white and red clover were strong receivers. Results show that N transfer increases with N application and from the 1st to the 2nd cut.
Tipo: Conference paper, poster, etc. Palavras-chave: Biodiversity and ecosystem services.
Ano: 2010 URL: http://orgprints.org/17887/4/17887.pdf
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15Nitrogen uptake from shallow- versus deep-rooted plants in multi-species mixtures and monoculture grassland Organic Eprints
Pirhofer-Walzl, K.; Høgh-Jensen, H.; Rasmussen, J.; Rasmussen, J.; Søegaard, K.; Eriksen, J..
Only few studies have explored the importance of functional diversity in temperate agricultural grasslands in relation to nitrogen (N) uptake. This study investigates the consequence of growing deep-rooted plants together with grass-clover mixtures in terms of N uptake efficiency from deep soil layers. The objective was to compare the N uptake of the shallow-rooted grassland species Lolium perenne and Trifolium repens; and the deep-rooted species Cichorium intybus and Medicago sativa in monocultures and mixtures. We hypothesized that growing deep-rooted plant species in mixture with shallow-rooted species increases the N uptake from deep soil layers partly through competition. A 15N tracer study was carried out with 15N enriched ammonium-sulphate placed at...
Tipo: Conference paper, poster, etc. Palavras-chave: Biodiversity and ecosystem services.
Ano: 2010 URL: http://orgprints.org/17886/1/EGF_conference_for_organic_e_prints.pdf
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Biomass production and N2-fixation in seven grass-legume mixtures Organic Eprints
Rasmussen, J.; Søegaard, K.; Eriksen, J..
Inclusion of forage legumes in low-input grassland mixtures improves biomass production and soil fertility trough addition of nitrogen (N) from N2-fixation. The impacts of different mixture of legumes and companion grasses on the N production of the forage mixture have rarely been investigated under comparable soil and climatic conditions. We conducted a field experiment on a sandy soil at two nitrogen levels with seven two-species grassland mixtures: alfalfa (Medicago sativa), bird’s-foot trefoil (Lotus corniculatus), red clover (Trifolium pratense), or white clover (Trifolium repens) in mixture with perennial ryegrass (Lolium perenne), and white clover in mixture with meadow fescue (Festuca pratensis), timothy (Phleum pratense), or hybrid ryegrass...
Tipo: Conference paper, poster, etc. Palavras-chave: Crop combinations and interactions; Nutrient turnover.
Ano: 2010 URL: http://orgprints.org/17882/4/17882.pdf
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Dyrkning af kløvergræs Organic Eprints
Søegaard, K.; Rasmussen, J.; Sehested, J.; Jensen, S.K.; Eriksen, J.
Vitaminer, mineraler og foderværdi i forskellige græsmarksarter samt bælgplanternes N-dynamik samt kløvertræthed
Tipo: Conference paper, poster, etc. Palavras-chave: Pasture and forage crops.
Ano: 2011 URL: http://orgprints.org/20621/4/20621.pdf
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Effecs of including forbs on N2-fixation and N yield in red clover-ryegrass mixtures Organic Eprints
Dhamala, N.R.; Rasmussen, J.; Carlsson, G; Søegaard, K.; Eriksen, J..
Background: Legume biological nitrogen (N2)-fixation is stimulated by neighboring non-fixing species, but studies of legume N2-fixation in temporary grasslands including non-leguminous forage herb (forb) species are rare. Methodology: We investigated N2-fixation and N yield in a range of species mixtures consisting of three forb species  chicory (Cichorium intybus L.), ribwort plantain (Plantago lanceolata L.) and caraway (Carum carvi L.)  mixed into a traditional perennial ryegrass (Lolium perenne L.) and red clover(Trifolium pratense L.) mixture at two fertilisation levels. Results: The percentage of red clover N derived from the atmosphere (%Ndfa) was higher in mixtures than in pure stand, but did not increase with inclusion of forbs. Red clover...
Tipo: Journal paper Palavras-chave: Crop combinations and interactions; Nutrient turnover.
Ano: 2018 URL: http://orgprints.org/34966/1/10.1007_s11104-017-3554-9.pdf
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Effect of deep-rooted plant species on 15Nitrogen uptake and herbage yield in temporary agricultural grasslands Organic Eprints
Pirhofer-Walzl, K.; Eriksen, J.; Rasmussen, J.; Søegaard, K.; Høgh-Jensen, H.; Rasmussen, J..
Aims: Increase of plant diversity has been suggested to enhance grassland productivity and resource use efficiency. Most studies on agricultural grasslands have focused on functional diversity of mixtures comprising legumes and non-legumes, but there is little knowledge of plant nutrient acquisition from deep- and shallow-rooted grassland plant species. To investigate whether deep-rooted (chicory: Cichorium intybus L.; Lucerne: Medicago sativa L.) and shallow-rooted (perennial ryegrass: Lolium perenne L.; white clover: Trifolium repens L.) grassland plant species differ in herbage yield and depth dependent soil N-access, we investigated in the field if 1) a mixture comprising shallow- and deep-rooted grassland plant species has greater herbage yields than...
Tipo: Journal paper Palavras-chave: Pasture and forage crops.
Ano: 2012 URL: http://orgprints.org/20614/4/20614.pdf
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Environmental impacts of grazed pastures Organic Eprints
Eriksen, J.; Ledgard, S.; Lou, J.; Schils, R.; Rasmussen, J..
Large nitrogen (N) surplus and return of excreta-N in localised patches at high N rates in intensively grazed pasture systems markedly increases the risk of N losses to waterways and the atmosphere. Here are described the main routes of N input to grazed pastures, losses via N leaching, methane (CH4) and nitrous oxide (N2O) emissions. Furthermore farm N budgets and N use efficiency in relation to management strategies that can be applied to reduce N losses are discussed. Nitrate leaching increases exponentially with increased inputs and is closely related to urine patches, which also influence the leaching of dissolved organic N. High N2O emission rates in grazed pastures are related to fertiliser-N or N in excreta combined with compaction by animal...
Tipo: Conference paper, poster, etc. Palavras-chave: Air and water emissions; Farm nutrient management.
Ano: 2010 URL: http://orgprints.org/17879/4/17879.pdf
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Fate of 15N- and 14C from labelled plant material: Recovery in perennial ryegrass-clover mixtures and in pore water of the sward Organic Eprints
Rasmussen, J.; Gjettermann, B.; Eriksen, J.; Jensen, E.S.; Høgh-Jensen, H..
The below ground C and N dynamics leading to organic and inorganic N leaching from perennial ryegrass-clover mixtures are not well understood. Based on the hypothesis that four different plant materials would degrade differently, a 16 months field experiment was conducted to determine (i) the source strength of labelled plant residues in dissolved inorganic N (DIN) and dissolved organic N (DON) in pore water from the plough layer, and (ii) the plant uptake of organically bound N. Litterbags containing 14C- and 15N-labelled ryegrass or clover roots or leaves were inserted into the sward of a ryegrass-clover mixture in early spring. The fate of the released 14C and 15N was monitored in harvested biomass, roots, soil, and pore water percolating from the...
Tipo: Journal paper Palavras-chave: Nutrient turnover; Soil biology; Air and water emissions.
Ano: 2008 URL: http://orgprints.org/16290/1/16290.pdf
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Forage legume impact on soil fertility and N balance Organic Eprints
Eriksen, J.; Søegaard, K.; Askegaard, M.; Hansen, E.M.; Rasmussen, J..
Dairy production systems in Europe are to a large extent based on ley-arable rotations. In the ley phase of such rotations nitrogen accumulation occurs as a result of (1) organic carbon accumulation in soil not disturbed by tillage operations and (2) a considerable nitrogen surplus in grasslands, particularly under grazing regimes where a large part of the N in ingested grass is recycled to soil via urine and faeces. The accumulation of N and C in grasslands starts soon after establishment, the rate asymptotically declining with age and depends on practices such as fertiliser level, animal feed composition, stocking density, length of grazing and the botanical composition of the sward. In these pasture systems, key perennial legumes are white clover...
Tipo: Conference paper, poster, etc. Palavras-chave: Nutrient turnover; Air and water emissions.
Ano: 2010 URL: http://orgprints.org/17881/4/17881.pdf
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Grassland carbon sequestration and emissions following cultivation in a mixed crop rotation Organic Eprints
Acharya, B.S.; Rasmussen, J.; Eriksen, J..
Grasslands are potential carbon sinks to reduce unprecedented increase in atmospheric CO2. Effect of age (1 to 4-yr-old) and management (slurry, grazing multispecies mixture) of a grass phase mixed crop rotation on carbon sequestration and emissions upon cultivation was compared with 17-yr-old grassland and a pea field as reference. Aboveground and root biomass were determined and soils were incubated to study CO2 emissions after soil disturbance. Aboveground biomass was highest in 1-yr-old grassland with slurry application and lowest in 4-yr-old grassland without slurry application. Root biomass was highest in 4-yr-old grassland, but all 1 to 4-yr-old grasslands were in between the pea field (0.81±0.094 g kg-1 soil) and the 17-yr-old grassland (3.17±0.22...
Tipo: Journal paper Palavras-chave: Soil quality; Biodiversity and ecosystem services.
Ano: 2012 URL: http://orgprints.org/22041/7/22041.pdf
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Kamdyrkning (drill) – et økologisk alternativ Organic Eprints
Henriksen, C.B.; Rasmussen, J..
I projektet CARMINA undersøges de potentielle fordele ved at anvende kamme som alternativ til pløjning. Det er tidligere vist at kamme kan reducere udvaskning af kvælstof, øge omsætningen af organisk stof og sikre en tidligere såning samt bedre etablering. I CARMINA kombineres kamme med dyrkning af fangafgrøder og inkorporering af husdyrgødning i en række nye forsøg.
Tipo: Conference paper, poster, etc. Palavras-chave: Nutrient turnover; Production systems; Soil tillage.
Ano: 2002 URL: http://orgprints.org/125/1/Kamdyrkning_fra_rapp_03_2002.pdf
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N2-fixation and residual effect of four legume species and four companion grass species Organic Eprints
Rasmussen, J.; Søegaard, K.; Eriksen, J..
Inclusion of forage legumes in low-input forage mixtures improves herbage production and soil fertility through addition of nitrogen (N) from N2-fixation. The impact of different grass–legume mixtures on the N contribution of the forage mixture has rarely been investigated under comparable soil and climatic conditions. We conducted a field experiment on a sandy soil at two nitrogen levels with seven twospecies forage mixtures: alfalfa, bird’s-foot trefoil, red clover, or white clover in mixture with perennial ryegrass, and white clover in mixture with meadow fescue, timothy, or hybrid ryegrass. We found high N2- fixation of more than 300 kg N ha−1 from both red clover and alfalfa even when the two mixtures received 300 kg total-N ha−1 in cattle slurry....
Tipo: Journal paper Palavras-chave: Crop combinations and interactions; Farm nutrient management.
Ano: 2012 URL: http://orgprints.org/20635/4/20635.pdf
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Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland Organic Eprints
Pirhofer-Walzl, K.; Rasmussen, J.; Høgh-Jensen, H.; Eriksen, J.; Søegaard, K.; Rasmussen, J..
Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red clover (Trifolium pratense L.) and lucerne (Medicago sativa L.) were leaf-labelled with 15N enriched urea during one growing season. N transfer to grasses (Lolium perenne L. and xfestulolium), white clover, red clover, lucerne, birdsfoot trefoil (Lotus corniculatus L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.), salad burnet (Sanguisorba minor L.)and caraway (Carum carvi L.) was assessed. Neighbouring plants contained greater amounts of N...
Tipo: Journal paper Palavras-chave: Pasture and forage crops.
Ano: 2012 URL: http://orgprints.org/20613/4/20613.pdf
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Root size fractions of ryegrass and white clover contributes differently to C and N inclusion in SOM Organic Eprints
Rasmussen, J.; Eriksen, J.; Jensen, E.S.; Høgh-Jensen, H..
Grass-clover mixtures are essential in many low-N-input cropping systems, but the importance of various root fractions for the below-ground N dynamics are not well understood. This may be due to the difficulties of studying root longevity and turnover in situ in mixtures. The present field study, investigated (1) the development in root biomass over two growing seasons and (2) the turnover of dual N-15- and C-14-labelled ryegrass and white clover root material. Litter bags containing various dual-labelled plant materials were incubated in cylinders inserted in the topsoil of a young ryegrass-clover ley. Disappearance of C-14 and N-15 from the litter bag material were studied for 1 year following incubation. Four times during two growing seasons, roots were...
Tipo: Journal paper Palavras-chave: Farming Systems; Biodiversity and ecosystem services.
Ano: 2010 URL: http://orgprints.org/17875/4/17875.pdf
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Soil carbon storage and yields of spring barley following grass leys of different age Organic Eprints
Christensen, B.T.; Rasmussen, J.; Eriksen, J.; Hansen, E.M..
The inclusion of leys in arable cropping is generally found to improve soil fertility. The effect of leys depends on their botanical composition and management, but the significance of individual management factors remains confounded in most studies. We quantified the effects of one- to six-year-old pure grass leys on soil C (0-20 cm) and yields of three subsequent test crops of spring barley (Hordeum vulgare) under-sown with Italian ryegrass (Lolium perenne). Each ley was a mixture of four grass species (Lolium perenne, Festuca pratensis, Phleum pratense, Poa pratensis), exposed to three to four cuts annually. Only mineral fertilizers were applied (225 kg N ha-1 yr-1). The yield of barley was tested at six rates of N fertilizer (0 to 150 kg N ha-1). The...
Tipo: Journal paper Palavras-chave: Nutrient turnover; Crop combinations and interactions; Air and water emissions.
Ano: 2009 URL: http://orgprints.org/16289/1/16289.pdf
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Udfordring eller mulighed for økologien Organic Eprints
El-Nagger, A.; Ounmaa, A.; Muukka, E.; Zaleckas, E.; Abraityté, G.; Jansons, I.; Rasmussen, J.; Ahnström, J.; Pirhofer-Walzl, K.; O'Doherty Jensen, K.; Jørgensen, K.F.; Sarunaite, L.; Bleidere, M.; Knudsen, M.T.; Pugliese, M.; Nielsen, M.H.M.; Muguerza, N.B.; Bakewell-Stone, P.; Hansen, P.K.; Abed-Ali Al-Kufaishi, S.A.; Kobayashi, S.; Rydberg, T.; Klubova, V.; Liorancas, V.; Høgh-Jensen, H..
During one intensive week in October 2005, the authors were gathered to discuss the impact that globalisation has on the Organic Food Systems and the opportunities that globalisation opens up for developing these systems. The meeting took place as a Ph.D. course under the auspices of the Research School of Organic Farming and Food Systems (SOAR; www.soar.dk). All participants research within Organic Agriculture and Food Production in one way or another.
Tipo: Newspaper or magazine article Palavras-chave: "Organics" in general Values; Standards and certification.
Ano: 2005 URL: http://orgprints.org/10492/1/10492.pdf
Registros recuperados: 16
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