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| Registros recuperados: 25 | |
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| 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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| Vinther, F.P.; Hansen, E.M.; Olesen, J.E.. |
| The impacts of crop rotation and input of organic matter in the form of green manure crops, straw residues and incorporation of catch crops on crop yield, nitrogen uptake, microbial biomass and activity was studied in unfertilised crop rotations differing in input of plant residues, i.e. high-input rotations with a grass-clover crop and catch crops included and low-input cereal rotations without catch crops. The parameters studied included substrate induced respiration (SIR), hydrolysis of fluorescein diacetate (FDA), arylsulfatase activity (ASA), N mineralisation, N2O emission, and soil respiration. These parameters were measured in bare soil plots, to estimate the effects of previous years crops and input of plant residues. In neighbouring plots crop... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Soil biology; Soil quality; Air and water emissions. |
| Ano: 2004 |
URL: http://orgprints.org/4012/1/Vinther%2C_Hansen_Olesen_2004.pdf |
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| Hansen, E.M.; Eriksen, J.; Vinther, F.P.. |
| Har man problemer med kløvertræthed i sine marker kan en løsning være, at dyrke grønbyg (byg høstet ved begyndende skridning) med udlæg af italiensk (ital.) rajgræs. Nye forsøg beskrevet her viser, at dyrkning af grønbyg med udlæg af ital. rajgræs giver mulighed for at reducere udvaskningen af kvælstof (N) til et minimum og samtidig opnå en stor produktion af grovfoder. I modsætning hertil er der normalt stor risiko for udvaskning af kvælstof ved ompløjning af kløvergræs på sandjorde. |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2005 |
URL: http://orgprints.org/5475/1/5475.PDF |
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| Hansen, E.M.; Eriksen, J.; Vinther, F.P.. |
| The objective of the study was to prevent the accumulation of high concentrations of mineral N in the soil during the drainage season by growing the presumably most effective catch crop, Italian ryegrass, undersown in barley as a green crop for silage on sandy soil. Further more, to examine the effect on two fields with different management of the grass-clover ley and therefore a different mineralization potential after ploughing. The green barley/Italian ryegrass treatment was compared with barley grown to maturity with and without an undersown conventional catch crop of perennial ryegrass. |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
| Ano: 2007 |
URL: http://orgprints.org/10621/1/10621.doc |
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| Hansen, E.M.; Eriksen, J.. |
| During the last 20 years the area with maize in Denmark has increased dramatically and reached 163,000 ha in 2008. Silage maize is easy to grow, is a suitable fodder for cows and goes well with grass-clover in the diet. This means that silage maize is often found in crop rotations with grass-clover on sandy soils in western Denmark. The ploughing in of grass-clover fields poses a serious risk of increased nitrate leaching on a coarse sandy soil, even when carried out in spring. With increased maize cropping, there is therefore a need for strategies to reduce nitrate leaching after ploughing of grass-clover.In the ICROFS project, OrgGrass, we examined the effect of catch crop and slurry application on nitrate leaching from maize after a spring-ploughed... |
| Tipo: Newspaper or magazine article |
Palavras-chave: Nutrient turnover; Air and water emissions. |
| Ano: 2009 |
URL: http://orgprints.org/17876/1/17876.pdf |
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| Hansen, E.M.; Eriksen, J.; Søegaard, K.; Kristensen, K.. |
| Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006-2007. In both years precipitation was above the long-term mean. The experiment was initiated in a 4-year-old grass-clover in south Denmark. Three treatments were included: grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm depth using ceramic suction cups. Because of considerable variation in measured nitrate concentrations, the 32 installed suction cups per treatment were insufficient to reveal... |
| Tipo: Journal paper |
Palavras-chave: Air and water emissions; Farm nutrient management. |
| Ano: 2012 |
URL: http://orgprints.org/20649/7/20649.pdf |
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| Vinther, F.P.; Hansen, E.M.; Olesen, J.E.. |
| The impacts of crop rotation and input of organic matter in the form of straw residues and incorporation of catch crops on crop yield, nitrogen uptake and microbial biomass and activity was studied in a field experiment initiated in 1996 at Research Centre Foulum. The parameters studied included substrate-induced respiration (SIR) from where microbial biomass C was calculated, hydrolysis of fluorescein diacetate (FDA), arylsulfatase activity (ASA), N mineralisation, N2O emission, and soil respiration. These experiments were carried out in bare soil plots to measure the effects of previous crops and input of organic matter. In 2001 measurements were carried out in four treatments where the crops in 2000 were winter wheat (W-w), pea-barley (P-b),... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover Soil quality Production systems Soil biology Air and water emissions Cereals; Pulses and oilseeds. |
| Ano: 2002 |
URL: http://orgprints.org/1790/1/Finn_Vinther_abstract.doc |
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| 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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| Hansen, E.M.; Eriksen, J.; Vinther, F.P.. |
| Nitrogen leaching following cultivation of grazed grass-clover on coarse sandy soil Background and objectives When grass-clover is ploughed there is a high risk of nitrogen leaching. The objective of this study was to measure the effectiveness of an early catch crop in reducing nitrogen leaching from coarse sandy soil. Barley as a green crop for silage was undersown with Italian ryegrass in spring and harvested at the beginning of early heading, and the Italian ryegrass was subsequently used for roughage production in autumn. Material and methods Experiments were established in spring 2003 on a commercial organic farm with a coarse sandy soil. Two fields with grass-clover were ploughed. One field, a 3-year-old grass-clover, had formed part of a... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover. |
| Ano: 2005 |
URL: http://orgprints.org/5476/2/5476.pdf |
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| Vinther, F.P.; Hansen, E.M.; Eriksen, J.. |
| Opløst organisk stof danner grundlaget for mange af de biogeokemiske processer der foregår i jorden. Der er foretaget talrige undersøgelser af dannelse og tab af organisk stof fra skovjorde, hvorimod kun få er gennemført i landbrugsjord. Det vides at græsmarker øger jordens pulje af organisk stof, men kendskabet til det organiske stofs skæbne efter ompløjning af græsmarker er mangelfuldt. Formålet med denne undersøgelse var at bestemme størrelsesordner for udvaskning af opløst organisk kulstof (DOC) og den samlede mængde mobilt organisk kulstof (MOC) i dyrkningssystemer med kløvergræs, med særlig fokus på perioden efter ompløjning af græsmarken. Undersøgelserne er gennemført dels i Foulum i et markforsøg anlagt med henblik på at måle kvælstofudvaskning og... |
| Tipo: Report chapter |
Palavras-chave: Nutrient turnover; Pasture and forage crops; Air and water emissions. |
| Ano: 2005 |
URL: http://orgprints.org/5373/1/5373.pdf |
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| Hansen, E.M.; Eriksen, J.; Vinther, F.P.. |
| Danish organic farmers experience increasing difficulties with clover soil fatigue due to continuous cultivation of clover. A solution could be to undersow barley with Italian ryegrass after ploughing of grass-clover where the barley could be used as a green crop for silage (i.e., barley harvested at the beginning of heading), and Italian ryegrass could be used for cutting in autumn. This method offers advantages not only for the farmer but also for the environment. When grass-clover is ploughed there is a high risk of N leaching. However, new field experiments show, that with the suggested method it is possible to reduce leaching to a minimum and simultaneously achieve a high production of roughage. |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2005 |
URL: http://orgprints.org/5474/1/5474.PDF |
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| Hansen, E.M.; Eriksen, J.; Vinther, F.P.. |
| Cultivation of grassland presents a high risk of nitrate leaching. This study aimed to determine if leaching could be reduced by growing spring barley (Hordeum vulgare L.) as a green crop for silage with undersown Italian ryegrass (Lolium multiflorum Lam.) compared with barley grown to maturity with or without an undersown conventional catch crop of perennial ryegrass (Lolium perenne L.). All treatments received 0,60 or 120 kg of ammonium-N ha-1 in cattle slurry. In spring 2003, two grass-clover fields (3 and 5 years old, respectively, with different management histories) were ploughed. The effects of the treatments on yield and nitrate leaching were determined in the first year, while the residual effects of the treatments were determined in the second year... |
| Tipo: Journal paper |
Palavras-chave: Soil. |
| Ano: 2007 |
URL: http://orgprints.org/21149/1/21149.pdf |
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| Vinther, F.P.; Hansen, E.M.; Olesen, J.E.. |
| In organic cropping systems, where commercial fertilisers not are used, the use of N2 fixing crops, such as grass-clover, is of crucial importance. Additionally, the use of catch crops will reduce the loss of nutrients from the soil and thereby maintain the nutritional status at a higher level leading to a sustainable crop production. The use N2 fixing crops and catch crops may also affect the microbial communities in the soil with consequences for the microbial biomass and activity. The objective of this study, which was a part of the DARCOF-project BIOMOD, was to investigate the influence of crop rotation, particularly the prehistory regarding plant residue amendment, on crop yields, soil respiration, N mineralisation, on emissions of the green... |
| Tipo: Newspaper or magazine article |
Palavras-chave: Nutrient turnover Soil quality Production systems Soil biology Cereals; Pulses and oilseeds. |
| Ano: 2003 |
URL: http://orgprints.org/1840/1/Finn_P_Vinther_e%2Dnews.doc |
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| Jacobsen, O.H.; Vinther, F.P.; Schjønning, P.; Hansen, E.M.; Eriksen, J.. |
| I Danmark har det høj prioritet, at vi kan drikke vores grundvand uden rensning. Der er en voksende erkendelse af, at rent grundvand kun kan opretholdes gennem en aktiv indsats. Amterne udpeger områder med særlig drikkevandsinteresser og efterfølgende zonerer de for arealer der er særlig nitrat- og pesticidfølsomme. En perspektivrig mulighed for at regulerede i forureningsfølsomme om-råder kan være, at man udlagde større sammenhængende arealer med økologisk jordbrug. Først og fremmest undgår man helt brug af pesticider. For kvælstof, vil tabet være afhængig af det økologi-ske dyrkningssystem og det er det der er fokus for denne undersøgelse. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover; Farm nutrient management; Air and water emissions. |
| Ano: 2004 |
URL: http://orgprints.org/5957/1/5957.doc |
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| Hansen, E.M.. |
| Klimaændringer og majs hører sammen, ligesom klimaændringer og risiko for udvaskning formentlig hører sammen. Noget tyder på, at dyrkning af majs og risiko for udvaskning også hører sammen. I et forsøg på grovsandet jord, hvor der blev høstet godt 13 tons tørstof pr. ha, blev der udvasket 86 kg N pr. ha i ugødet majs efter kløvergræs. Der er derfor god grund til at benytte dyrkningsmetoder, der effektivt kan reducere risikoen for udvaskning efter majs. Udlæg af efterafgrøder er en oplagt mulighed, da efterafgrøder er en velkendt metode til at redu-cere udvaskningen – så hvor svært kan det være? |
| Tipo: Newspaper or magazine article |
Palavras-chave: Nutrient turnover; Air and water emissions. |
| Ano: 2010 |
URL: http://orgprints.org/17878/1/17878.pdf |
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| Registros recuperados: 25 | |
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