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| Registros recuperados: 31 | |
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| Nørremark, Michael; Griepentrog, Hans W.. |
| The objective of this paper is to analyse and define the field conditions close to the crop plants of sugar beet (Beta vulgaris L.). The aim is to use this study for the choice and development of new physical weeding methods to target weeds at individual plant scale level. It was found that the close to crop area is like a ring structure, comprising an area between an inner- and outer-circle around the sugar beet seedling. Physical weeding should not be applied to the area within the inner circle. The radius of the inner circle increases with the appearance of young beet leaves during the growth season. It was also found, that no weeds were germinating within 1 cm around individual sugar beet seedlings. Therefore this distance should be added to the... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management. |
| Ano: 2004 |
URL: http://orgprints.org/4834/1/4834.pdf |
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| Griepentrog, Hans W.; Nørremark, Michael; Nielsen, Henning; Blackmore, Simon. |
| Individual plant care may well become embodied in precision farming in the future and will lead to new opportunities in agricultural crop management. The objective of this project was to develop and evaluate a data logging system attached to a precision seeder to enable high accuracy seed position mapping of a field of sugar beet. A Real Time Kinematic Global Positioning System (RTK GPS), optical seed detectors and a data logging system were retrofitted on to a precision seeder to map the seeds as they were planted. The average error between the seed map and the actual plant map was about 16–43 mm depending on vehicle speed and seed spacing. The results showed that the overall accuracy of the estimated plant positions was acceptable for the guidance of... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2005 |
URL: http://orgprints.org/4831/1/4831.pdf |
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| Tyystjärvi, Esa; Nørremark, Michael; Mattila, Heta; Keränen, Mika; Hakala-Yatkin, Marja; Ottosen, Carl-Otto; Rosenqvist, Eva. |
| Automatic identification of crop and weed species is required for many precision farming practices. The use of chlorophyll fluorescence fingerprinting for identification of maize and barley among six weed species was tested. The plants were grown in outdoor pots and the fluorescence measurements were done in variable natural conditions. The measurement protocol consisted of 1 s of shading followed by two short pulses of strong light photosynthetic photon flux density 1700 lmol m-2 s-1) with 0.2 s of darkness in between. Both illumination pulses caused the fluorescence yield to increase by 30–60% and to display a rapid fluorescence transient resembling transients obtained after long dark incubation. A neural network classifier, working on 17 features... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2011 |
URL: http://orgprints.org/20654/4/20654.pdf |
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| Rasmussen, Jesper; Nørremark, Michael. |
| The main drawback by using crop soil cover in weed harrowing research is that it is assessed by visual scores, which are biased and context dependent. This problem may be solved by using digital image analysis. In this paper a new image capture standard and digital image analysis procedure was used to illustrate three key issues in relation to weed harrowing; selectivity, resistance and recovery. All issues require reliable assessments of crop soil cover. Crop soil cover was deduced from assessments of leaf cover, which is defined as the proportion of pixels in digital images determined to be green. Objective assessments of leaf cover and crop soil cover showed that the selectivity of weed harrowing in winter wheat and spring barley was unaffected by... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management. |
| Ano: 2007 |
URL: http://orgprints.org/10758/1/10758.pdf |
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| Swain, Kishore; Nørremark, Michael; Jørgensen, Rasmus N.; Midtiby, Henrik S.; Green, Ole. |
| Weed identification and control is a challenge for intercultural operations in agriculture. As an alternative to chemical pest control, a smart weed identification technique followed by mechanical weed control system could be developed. The proposed smart identification technique works on the concept of ‘active shape modelling’ to identify weed and crop plants based on their morphology. The automated active shape matching system (AASM) technique consisted of, i) a Pixelink camera ii) an LTI Lehrstuhlfuer technische informatik) image processing library, iii) a laptop pc with the Linux OS. A 2-leaf growth stage model for Solanum nigrum L. (nightshade) is generated from 32 segmented training images in Matlab software environment. Using the AASM algorithm, the... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2011 |
URL: http://orgprints.org/20658/4/20658.pdf |
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| Nørremark, Michael; Swain, Kishore; Melander, Bo. |
| Use of chemical has been reduced in agriculture for controlling weeds emergence. The use of alternative systems, such as cultural practices (mulching, flame, intercropping etc.) and mechanical system (hoe, tine etc.) has been introduced by various researchers. Automation technique based on sensors controlled system has enhanced the efficiency of the mechanical system for weed control. Mostly, low cost image acquisition sensors and optical sensor to detect the plant ensuring swift operation of vehicles close the crop plants to remove competitive weeds. The available system need to be evaluated to get best possible system for close to plant (CTP) weed removal. In the study various non-chemical weed control measures has been explored and 30 mechanical tools... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management. |
| Ano: 2009 |
URL: http://orgprints.org/20656/4/20656.pdf |
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| Swain, Kishore C.; Nørremark, Michael; Bochtis, Dionysis; Sørensen, Claus Grøn; Green, Ole. |
| Robots in agriculture offer new opportunities for real time weed identification and quick removal operations. Weed identification and control remains one of the most challenging task in agriculture, particularly in organic agriculture practices. Considering environmental impacts and food quality, the excess use of chemicals in agriculture for controlling weeds and diseases is decreasing. The cost of herbercides and their field applications must be optimized. As an alternative, a smart weed identification technique followed by the mechanical and thermal weed control can fulfill the organic farmers’ expectations. The smart identification technique works on the concept of ‘shape matching’ and ‘active shape modeling’ of plant and weed leafs. The automated... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management. |
| Ano: 2010 |
URL: http://orgprints.org/20653/4/20653.pdf |
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| Sørensen, Claus G.; Nørremark, Michael; Jørgensen, Rasmus N.; Jensen, Kjeld; Maagaard, Jørgen; Jensen, Lars Aa.. |
| Based on the development of a robotic tool carrier (Hortibot) equipped with weeding tools, a feasibility study was carried out to evaluate the viability of this innovative technology. The feasibility was demonstrated through a targeted evaluation adapted to the obtainable knowledge on the system performance in horticulture. A usage scenario was designed to set the implementation of the robotic system in a row crop of seeded bulb onions considering operational and functional constraints in organic crop, production. This usage scenario together with the technical specifications of the implemented system provided the basis for the feasibility analysis, including a comparison with a conventional weeding system. Preliminary results show that the automation... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Buildings and machinery. |
| Ano: 2007 |
URL: http://orgprints.org/11263/1/ASABE_paper_(2007)_%2DS%C3%B8rensen.pdf |
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| Melander, Bo; Nørremark, Michael; Fløjgaard, Erik. |
| The control of perennial weeds in organic crop production needs reconsideration to minimise losses of nutrients through leaching. Long post-harvest periods with mechanical weed control hinder a plant cover with the purpose of taking up nutrients not being utilised by the main crop to maintain soil fertility. To meet the interests of nutrient and weed management, we suggest a new concept for the control of perennial weeds with propagules placed within the plough layer. The concept comprises uprooting and immediate removal of Elytrigia repens rhizomes with modified machinery to allow for a quick re-establishment of a plant cover to avoid longer periods of bare soil. Four passes with a modified cultivator where each pass was followed by rhizome removal and... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2012 |
URL: http://orgprints.org/22277/13/22277.pdf |
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| Kristensen, Erik Fløjgaard; Melander, Bo; Nørremark, Michael. |
| Elymus repens (coach grass) is traditionally controlled by repeated and prolonged stubble cultivation. However, the efficacy is strongly depending on weather and secondly on the exposure of rhizomes. The shorter the required period of cultivation stays the more compliance with the objective in organic farming where farmers aim at minimizing leaching of nutrients by keeping the soil plant-covered during autumn and winter. Effective technique and strategies for uprooting, exposing and destroying Elymus repens are needed. In a Danish organic research project the focus is on technological solutions for uprooting, exposing and destroying of the rhizomes within a short time span. Machines of standard type, modified machines and machines constructed for other... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management. |
| Ano: 2010 |
URL: http://orgprints.org/18343/1/18343.pdf |
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| Rasmussen, Jesper; Nørremark, Michael; Bibby, Bo Martin. |
| A web-based digital image analysis tool (IMAGING Crop Response Analyser) has been developed, tested and made public (www.imaging-crops.dk). This new technology makes possible objective estimations of crop-soil cover (i.e. how much crop is buried with soil) associated with post-emergence weed control with spring tine harrows, rotary hoes and other weeders. Objective estimation of crop-soil cover offers new possibilities to improve decision support of physical weed control practises with low selectivity because trade-offs between weed control and resulting injury to the associated crop now may be quantified, communicated and incorporated into models. The objective of this resentation is to suggest key parameters and research priorities for future research... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management; Technology assessment. |
| Ano: 2008 |
URL: http://orgprints.org/13688/1/13688.pdf |
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| Melander, Bo; Nørremark, Michael; Kristensen, E.F.. |
| Mechanical weed control of perennial weeds in organic crop production over long post-harvest periods is incompatible with the establishment of cover crops for improving soil quality and preventing nutrient leaching. We suggest a new concept that comprises uprooting and immediate removal of vegetative propagules located within the plough layer to allow for quick re-establishment of a plant cover. A field experiment comparing the effects of conventional practices (stubble cultivation) with different combinations of rotary cultivation (1, 2 or 4 passes) and cover crops (none vs rye-vetch-mustard mixture) on Elytrigia repens rhizome removal, shoot growth and suppression of a subsequent barley crop were examined in two growing seasons. Four passes with a... |
| Tipo: Journal paper |
Palavras-chave: Crop husbandry; Weed management. |
| Ano: 2013 |
URL: http://orgprints.org/25676/7/25676.pdf |
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| Hefner, M.; Labouriau, R.; Nørremark, Michael; Kristensen, Hanne Lakkenborg. |
| Increased farm machinery weight in agricultural production results in soil compaction. Controlled traffic farming (CTF) restricts traffic to permanent lanes, thereby creating traffic free beds for crop production. Field experiments were conducted at two organic vegetable farms in Denmark, on a sandy loam (2013–2016) and on coarse sand (2013–2015) to investigate CTF effects compared with random traffic farming (RTF) on vegetable yield, root growth, and soil mineral nitrogen (N). Root growth was measured using minirhizotrons. White cabbage, potato, and beetroot yield increased by 27%, 70% and 42%, respectively, in CTF compared with RTF in 2015 and winter squash indicated a yield increase of 43% on sandy loam in 2016. White cabbage (2015) and potato, beetroot... |
| Tipo: Journal paper |
Palavras-chave: Soil quality; Crop combinations and interactions; Nutrient turnover; Soil tillage; Air and water emissions; Vegetables; Root crops. |
| Ano: 2019 |
URL: http://orgprints.org/35456/1/Hefner%20et%20al%202019%20Controlled%20traffic%20farming.pdf |
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| Griepentrog, Hans W.; Nørremark, Michael. |
| Mulighederne indenfor præcisionsjordbrug er i de seneste år blevet mangfoldige. Præcisionsjordbrug har hidtil været anvendt på markniveau til graduering af forskellige produktionsmidler. Dette kan have en miljøforbedrende effekt både mht. udvaskning af nærringssalte og pesticider. Det overordnede mål har derved været at forøge effektiviteten af det enkelte produktionsmiddel. I den sammenhæng er det interessant at undersøge mulighederne for at forøge effektiviteten af det enkelte produktionsmiddel ved direkte at tilføre midlet til hver enkel kulturplante. Problemstillingen er derfor at udvikle teknologi, som gør det muligt at positionsbestemme hver enkel kulturplante på en mark. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management. |
| Ano: 2002 |
URL: http://orgprints.org/4833/1/4833.pdf |
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| Gundersen, Hanne; Rasmussen, Jesper; Nørremark, Michael. |
| This study defines crop tolerance to post-emergence weed harrowing as the combined effect of crop resistance and crop recovery. Crop resistance is the ability of the crop to resist soil covering and recovery is the ability to recover in terms of yield. In two experiments, resistance, recovery and tolerance were quantified in barley, oat, wheat and triticale by a new method based on digital image analysis. Important differences in resistance, recovery and tolerance among species were seen and resistance was not linked to recovery. Oat showed higher resistance than wheat, and barley. Triticale showed the lowest resistance. Oat and barley showed both lower ability to recover from soil covering than wheat, and triticale showed complete recovery. Triticale was... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management. |
| Ano: 2006 |
URL: http://orgprints.org/8082/1/8082.pdf |
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| Registros recuperados: 31 | |
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