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| Registros recuperados: 54 | |
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| Dalgaard, Tommy; Hutchings, Nicholas J.; Dragosits, U.; Olesen, J.E.; Kjeldsen, Chris; Drouet, J.L.; Cellier, P.. |
| The aim of this study is to illustrate the importance of farm scale heterogeneity on nitrogen (N) losses in agricultural landscapes. Results are exemplified with a chain of N models calculating farm-N balances and distributing the N-surplus to N-losses (volatilisation, denitrification, leaching) and soil-N accumulation/release in a Danish landscape. Possible non-linearities in upscaling are assessed by comparing average model results based on (i) individual farm level calculations and (ii) averaged inputs at landscape level. Effects of the non-linearities that appear when scaling up from farm to landscape are demonstrated. Especially in relation to ammonia losses the non-linearity between livestock density and N-loss is significant (p > 0.999), with... |
| Tipo: Journal paper |
Palavras-chave: Air and water emissions; Landscape and recreation; Farm nutrient management. |
| Ano: 2011 |
URL: http://orgprints.org/19043/4/19043.pdf |
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| Hauggaard-Nielsen, H; Ambus, P; Dalgaard, T; Johansen, A; Jørgensen, U; Nielsen, A.M.; Nielsen, L.H.; Olesen, J.E.; Roepstorff, A; Skytte, K; Smith, J.E.; Thomsen, A.B.; Thomsen, M.H.; Jensen, E.S.. |
| Energy production and energy use in organic agriculture (OA) need to be addressed in order to reduce the reliance on non-renewable fossil fuels and minimize greenhouse gas (GHG) emissions. Thus, there is an obligation to find consensus between the apparent opposing aims of renewable (bio) energy production and soil fertility in OA. This project aims at designing and evaluate a combined concept for biomass and bio-energy production in OA, while considering soil fertility. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Farm nutrient management; Biodiversity and ecosystem services; Social aspects; Technology assessment; Air and water emissions; Farm economics. |
| Ano: 2007 |
URL: http://orgprints.org/11312/1/NJF2007%2DBioConcens.pdf |
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| Berntsen, J.; Petersen, B.M.; Olesen, J.E.; Eriksen, J.; Søegaard, K.. |
| The FASSET farm model was used to simulate production in an experiment where a grass-clover or a grass ley was either cut or grazed with dairy cows receiving low or high N sup-plements. The six different ley types were ploughed in and followed by three years with spring cereals with undersown catch crops. The original model was extended with a new grass and clover model, which included the capability to simulate rhizodeposition and root growth. The new model predicted the observed annual carbon (C) and nitrogen (N) production satisfactorily. The simulated first year residual effects of a cut grass or grass-clover ley varied between 0 and 34, while the residual effect of a grazed grass or grass-clover ley varied between 71 and 150 fertilizer equivalents... |
| Tipo: Journal paper |
Palavras-chave: Denmark. |
| Ano: 2005 |
URL: http://orgprints.org/4592/1/4592.pdf |
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| Li, X.; Sørensen, P.; Petersen, S.O.; Olesen, J.E.. |
| Legume-based catch crops (LBCCs) may be an important source of nitrogen (N) in organic crop rotations since they are capable of taking up N both from the soil and from the atmosphere via biological N fixation (BNF). Consequently, they may help improve the crop yield through enhancing soil fertility and crop N supply. On the other hand, the legume-based catch crops may also have a negative impact on the climate as they may enhance the emissions of nitrous oxide (N2O), which is a powerful greenhouse gas. Therefore, the findings from two research projects HighCrop (Organic RDD 2) and Legume Future (EU-FP7) are promising, as they show that a higher level of N2O emission is not necessarily the consequence of growing LBCC. |
| Tipo: Web product |
Palavras-chave: Composting and manuring; Nutrient turnover. |
| Ano: 2015 |
URL: http://orgprints.org/28938/1/28938.pdf |
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| Melander, B.; Olesen, J.E.. |
| Weed problems can constrain organic crop production resulting in significant losses in yield and quality. Especially perennial weed species such as Elytrigia repens, Cirsium arvense and Tussilago farfara are posing problems as arable cropping systems do not hamper their vegetative proliferation sufficiently. Annual weeds may also reach unacceptable infestation levels leaving the growers with poor yielding crops and severe future weed problems owing to the shedding and spread of weed seeds. Effective weed management is a key component for successful organic crop production and a prerequisite to increase the yielding potential of many organic crop production systems. Weed problems are most severe on stockless arable farms because the supply of nutrients can... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop combinations and interactions; Weed management. |
| Ano: 2013 |
URL: http://orgprints.org/24550/1/24550.pdf |
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| Vinther, F.P.; Olesen, J.E.. |
| Models for simulating nitrogen leaching are often based on simulations of a number of individual processes in the soil, such as turnover of organic matter, nitrogen mineralisation and immobilisation, nitrification, denitrification etc. It has been found that the models used under Danish conditions (DAISY and/or FASSET) have some limitations especially concerning the turnover of organic matter with implications on e.g. soil respiration. Therefore, the models are being modified and for calibration of the model measurements of in situ soil respiration using a portable CO2-analyser, nitrogen mineralization using a field incubation technique and N2O emission using a static chamber method, were carried out during the growing season 2001. The measurements were... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Soil quality; Soil biology; Air and water emissions. |
| Ano: 2001 |
URL: http://orgprints.org/1816/1/Abstract_Finn_Vinther_Denmark.doc |
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| Pugesgaard, S.; Dalgaard, T.; Jørgensen, U.; Olesen, J.E.; Møller, H.; Jensen, E.S.. |
| Can biogas and bioethanol production make organic farming more sustainable? - Results from a model for the fossil energy balance, Nitrogen losses, and greenhouse gas emissions in a 1000 ha energy catchment with organic dairy farming and integrated biogas and bioethanol production. Dalgaard T1, Pugesgaard S1, Jørgensen U1, Olesen JE1, Møller HB1 and Jensen ES2 1) Dept. Agroecology and Environment. Faculty of Agricultural Sciences (DJF), University of Aarhus. DK-8830 Tjele. Denmark. Contact: tommy.dalgaard@agrsci.dk 2) Biosystems Department, Risø DTU, The National Laboratory for Sustainable Energy, The Technical University of Denmark DK-4000 Roskilde, Denmark The vision of organic farming systems, independent of fossil energy resources, with... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Farm nutrient management; Air and water emissions. |
| Ano: 2008 |
URL: http://orgprints.org/14801/1/14801.pdf |
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| Olesen, J.E.. |
| Landbruget øver en væsentlig indflydelse på kvaliteten af både grundvand og overfladevand (vand-løb, søer og fjorde) gennem udledning af pesticider, kvælstof og fosfor. Alle stoffer har væsentlig betydning for kvaliteten af overfladevand, mens der for beskyttelsen af grundvandet har været størst fokus på at forhindre nedsivning af pesticider og reduktion af nitratudvaskningen fra landbrugsarea-ler, især i områder med indvinding af grundvand. Vandmiljøplanerne (VMP) har haft størst fokus på reduktion af kvælstofudvaskningen. Dog er der med VMP-III fra 2003 også inkluderet tiltag til reduktion af landbrugets udledning af fosfor til vandløb, søer og fjorde. I forbindelse med den faglige evaluering forud for VMP-II blev det anslået, at økologisk jord-brug i... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Air and water emissions. |
| Ano: 2004 |
URL: http://orgprints.org/4672/1/4672.doc |
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| Chirinda, N.; Kracher, D.; Porter, J.R.; Olesen, J.E.; Petersen, B.M.; Doltra, J.; Kiese, R.; Butterbach-Bahl, K.. |
| Modelling of soil emissions of nitrous oxide (N2O) and carbon dioxide (CO2) is complicated by complex interactions between processes and factors influencing their production, consumption and transport. In this study N2O emissions and heterotrophic CO2 respiration were simulated from soils under winter wheat grown in three different organic and one inorganic fertilizer-based cropping system using two different models, i.e., MoBiLE-DNDC and FASSET. The two models were generally capable of simulating most seasonal trends of measured soil heterotrophic CO2 respiration and N2O emissions. Annual soil heterotrophic CO2 respiration was underestimated by both models in all systems (about 10−30% by FASSET and 10−40% by MoBiLE-DNDC). Both models overestimated annual... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Air and water emissions. |
| Ano: 2010 |
URL: http://orgprints.org/18512/1/Chirinda_et_al_(modelling).pdf |
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| Berntsen, J.; Petersen, B.M.; Kristensen, I.S.; Olesen, J.E.. |
| Med udgangspunkt i regnskabsdata fra Fødevareøkonomisk Institut (FØI) og data fra Centrale Registre (CR) blev importen af kvælstof (N) i gødning til marken til konventionelle og økologiske planteavlere estimeret til hhv. 129 og 51 kg N ha-1 år-1. Desuden blev der med udgangspunkt i den aktuelle afgrødefordeling opstillet et generelt sædskifte for hver af de to systemer. Det opstillede sædskifte for den økologiske planteavl havde en høj andel af vårsæd og desuden 20% kløvergræs, mens den konventionelle planteavl var domineret af kornafgrøder primært i form af vintersæd. Med baggrund i disse model-sædskifter blev N-balancen på markniveau beregnet ved anvendelse af FASSET modellen. Dette inkluderede også N-udvaskning og ændring i jordens Npulje. Alle... |
| Tipo: Report |
Palavras-chave: Nutrient turnover; Production systems; Farming Systems; Air and water emissions. |
| Ano: 2004 |
URL: http://orgprints.org/4605/1/4605.pdf |
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| Berntsen, J.; Petersen, B.M.; Olesen, J.E.. |
| Measurements of crop yield and soil carbon in the Bad Lauchstädt long-term fertiliser experiment were analysed with the FASSET model. The model satisfactorily predicted yield and soil carbon development in four treatments with no fertiliser, mineral fertiliser, farm yard manure and farm yard manure plus mineral fertiliser, respectively. However, there was a residual between the observed and simulated yield, which was correlated with year. This could be attributed to an increase in observed yields during the last six decades. Scenario analysis showed that the most probable explanation for this yield increase was the use of new crop varieties and/or pesticides, while the increase in atmospheric CO2 and changes in local N deposition were of lesser importance.... |
| Tipo: Journal paper |
Palavras-chave: Soil biology. |
| Ano: 2006 |
URL: http://orgprints.org/10591/2/10591.pdf |
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| Doltra, J.; Gallejones, P.; Olesen, J.E.; Hansen, S.; Frøseth, R.B.; Krauss, M.; Stalenga, J.; Jończyk, K.; Martínez-Fernández, A.; Pacini, G.C.. |
| Soil fertility building measures should be explored at the short and long-term for an adequate evaluation of their impact on sustaining yields and of its environmental consequences in crop rotations under organic farming. For such a purpose, process-based crop models are potential useful tools to complement and upscale field observations under a range of soil and climatic conditions. Organic rotations differ in soil fertility dynamics in comparison to conventional farming but very few modelling studies have explicitly considered this specific situation. Here, we evaluate the FASSET model to predict the effects of different fertility management options in organic crop rotations on dry matter (DM) and nitrogen (N) yield, and soil N dynamics, including N2O... |
| Tipo: Journal paper |
Palavras-chave: Soil quality; Nutrient turnover; Soil tillage. |
| Ano: 2019 |
URL: http://orgprints.org/34308/1/doltra-etal-2019_FCR_Vol233_p1-11.pdf |
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| Olesen, J.E.. |
| Den forventede udvidelse af det økologisk dyrkede areal i Danmark er betinget af øget planteproduktion, som kræver højere og mere stabile udbytter. Denne udfordring skal kunne løses samtidig med at importen af konventionel husdyrgødning udfases og miljøpåvirkningen, f.eks. udledningen af drivhusgasser, reduceres væsentligt. HighCrop har to hoved-hypoteser: 1) Højere udbytter og mindre miljøpåvirkning kan opnås ved at inddrage flerårige energiafgrøder og forbedre styring af kvælstof (N) frigivet fra efterafgrøder, grøngødninger og afgrøderester; og 2) Lave udbytter i praktisk økologisk jordbrug skyldes et vidensgab mellem forskning og praksis, som kræver nye strategiske planlægningsværktøjer for at løse. HighCrop bygger på et tæt samarbejde mellem... |
| Tipo: Report |
Palavras-chave: Crop combinations and interactions Cereals; Pulses and oilseeds Air and water emissions Weed management. |
| Ano: 2014 |
URL: http://orgprints.org/26631/1/26631.pdf |
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| Chirinda, N.; Olesen, J.E.; Porter, J.R.; Schjønning, P.. |
| Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots in Sept 2007, April... |
| Tipo: Journal paper |
Palavras-chave: Soil biology; Nutrient turnover; Air and water emissions. |
| Ano: 2010 |
URL: http://orgprints.org/18511/1/18511.pdf |
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| Chirinda, N.; Carter, M.S; Albert, K.R.; Ambus, P.; Olesen, J.E.; Porter, J.R.; Petersen, S.O.. |
| Conventional cropping systems rely on targeted short-term fertility management, whereas organic systems depend, in part, on long-term increase in soil fertility as determined by crop rotation and management. Such differences influence soil nitrogen (N) cycling and availability through the year. The main objective of this study was to compare nitrous oxide (N2O) emissions from soil under winter wheat (Triticum aestivum L.) within three organic and one conventional cropping system that differed in type of fertilizer, presence of catch crops and proportion of N2-fixing crops. The study was replicated in two identical long-term crop rotation experiments on sandy loam soils under different climatic conditions in Denmark (Flakkebjerg–eastern Denmark and... |
| Tipo: Journal paper |
Palavras-chave: Farming Systems; Air and water emissions; Environmental aspects. |
| Ano: 2010 |
URL: http://orgprints.org/18510/1/chirinda_et_al_2010_%28N2O%29.pdf |
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| Rasmussen, I.A.; Askegaard, M.; Olesen, J.E.; Kristensen, K.. |
| We investigated the effects on annual weeds of location, weed control, manure application and catch crops and their interactions in a crop rotation with cereals and pulses for grain during conversion to organic farming in order to better understand the combined effects of management. An experiment with a four-year crop rotation (spring barley/undersown ley, grass-clover, winter wheat, pea/barley) was carried out from 1997 to 2000 under organic conditions at three locations in Denmark with four treatments: with and without catch crop, and with and without manure. Mechanical weed control was reduced or absent in cereals or pulses with undersown catch crops or grass-clover. Manure application increased weed biomass, but not the proportion of total biomass... |
| Tipo: Journal paper |
Palavras-chave: Cereals; Pulses and oilseeds Crop combinations and interactions Weed management. |
| Ano: 2006 |
URL: http://orgprints.org/7904/1/7904.pdf |
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| Rasmussen, I.A.; Askegaard, M.; Olesen, J.E.. |
| A crop rotation experiment was established in 1997 at three locations representing different soil types and climates. Three factors were tested: crop rotation, catch crop and manure. Catch crop reduced nitrate leaching, but prohibited stubble cultivation. The use of catch crops resulted in increased levels of perennial weeds (E. repens) at one location, while at another; the level of C. arvense was not affected by catch crops, when compared with the use of stubble cultivation. Management of perennial weeds should include considerations of where in a crop rotation to use stubble cultivation, and this should preferably not be after a pulse crop. Catch crops are a more profitable way to manage C. arvense than stubble cultivations. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Cereals; Pulses and oilseeds Crop combinations and interactions Weed management. |
| Ano: 2005 |
URL: http://orgprints.org/6070/1/6070a.pdf |
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| Registros recuperados: 54 | |
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