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See detailUsing UAV Collected RGB and Multispectral Images to Evaluate Winter Wheat Performance Across a Site Characterized by Century-Old Biochar Patches in Belgium
Heidarian Dehkordi, Ramin ULiege; Burgeon, Victor ULiege; Fouche, Julien et al

in Remote sensing (2020), 12

Remote sensing data play a crucial role in monitoring crop dynamics in the context of precision agriculture by characterizing the spatial and temporal variability of crop traits. At present there is ... [more ▼]

Remote sensing data play a crucial role in monitoring crop dynamics in the context of precision agriculture by characterizing the spatial and temporal variability of crop traits. At present there is special interest in assessing the long-term impacts of biochar in agro-ecosystems. Despite the growing body of literature on monitoring the potential biochar effects on harvested crop yield and aboveground productivity, studies focusing on the detailed crop performance as a consequence of long-term biochar enrichment are still lacking. The primary objective of this research was to evaluate crop performance based on high-resolution unmanned aerial vehicle (UAV) imagery considering both crop growth and health through RGB and multispectral analysis, respectively. More specifically, this approach allowed monitoring of century-old biochar impacts on winter wheat crop performance. Seven Red-Green-Blue (RGB) and six multispectral flights were executed over 11 century-old biochar patches of a cultivated field. UAV-based RGB imagery exhibited a significant positive impact of century-old biochar on the evolution of winter wheat canopy cover (p-value = 0.00007). Multispectral optimized soil adjusted vegetation index indicated a better crop development over the century-old biochar plots at the beginning of the season (p-values < 0.01), while there was no impact towards the end of the season. Plant height, derived from the RGB imagery, was slightly higher for century-old biochar plots. Crop health maps were computed based on principal component analysis and k-means clustering. To our knowledge, this is the first attempt to quantify century-old biochar effects on crop performance during the entire growing period using remotely sensed data. Ground-based measurements illustrated a significant positive impact of century-old biochar on crop growth stages (p-value of 0.01265), whereas the harvested crop yield was not affected. Multispectral simplified canopy chlorophyll content index and normalized difference red edge index were found to be good linear estimators of harvested crop yield (p-value(Kendall) of 0.001 and 0.0008, respectively). The present research highlights that other factors (e.g., inherent pedological variations) are of higher importance than the presence of century-old biochar in determining crop health and yield variability. [less ▲]

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See detailRemotely-sensed assessment of the impact of century-old biochar on chicory crop growth using high-resolution UAV-based imagery
Heidarian Dehkordi, Ramin ULiege; Denis, Antoine ULiege; Fouche, Julien et al

in International Journal of Applied Earth Observation and Geoinformation (2020), 91(September 2020),

In recent years, special attention has been given to the long-term effects of biochar on the performance of agro-ecosystems owing to its potential for improving soil fertility, harvested crop yields, and ... [more ▼]

In recent years, special attention has been given to the long-term effects of biochar on the performance of agro-ecosystems owing to its potential for improving soil fertility, harvested crop yields, and aboveground biomassproduction. The present experiment was set up to identify the effects on soil-plant systems of biochar producedmore than 150 years ago in charcoal mound kiln sites in Wallonia (Belgium). Although the impacts of biochar onsoil-plant systems are being increasingly discussed, a detailed monitoring of the crop dynamics throughout thegrowing season has not yet been well addressed. At present there is considerable interest in applying remotesensing for crop growth monitoring in order to improve sustainable agricultural practices. However, studiesusing high-resolution remote sensing data to focus on century-old biochar effects are not yet available. For thefirst time, the impacts of century-old biochar on crop growth were investigated at canopy level using high-resolution airborne remote sensing data over a cultivatedfield. High-resolution RGB, multispectral and thermalsensors mounted on unmanned aerial vehicles (UAVs) were used to generate high frequency remote sensinginformation on the crop dynamics. UAVs wereflown over 11 century-old charcoal-enriched soil patches and theadjacent reference soils of a chicoryfield. We retrieved crucial crop parameters such as canopy cover, vegetationindices and crop water stress from the UAV imageries. In addition, our study also providesin-situmeasurementsof soil properties and crop traits. Both UAV-based RGB imagery andin-situmeasurements demonstrated that thepresence of century-old biochar significantly improved chicory canopy cover, with greater leaf lengths in biocharpatches. Weighted difference vegetation index imagery showed a negative influence of biochar presence on plantgreenness at the end of the growing season. Chicory crop stress was significantly increased by biochar presence,whereas the harvested crop yield was not affected. The main significant variations observed between referenceand century-old biochar patches usingin situmeasurements of crop traits concerned leaf length. Hence, theoutput from the present study will be of great interest to help developing climate-smart agriculture practicesallowing for adaptation and mitigation to climate. [less ▲]

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See detailTravaux Pratiques de Télédétection Spatiale II - Avec données et logiciels libres
Denis, Antoine ULiege

Learning material (2020)

Ce manuel présente une série d’exercices de télédétection spatiale, prêts à l’emploi, avec données et logiciels libres. Les exercices vont du « niveau découverte » à un « niveau plus avancé » tout en ... [more ▼]

Ce manuel présente une série d’exercices de télédétection spatiale, prêts à l’emploi, avec données et logiciels libres. Les exercices vont du « niveau découverte » à un « niveau plus avancé » tout en restant très abordables pour des étudiants de Master 1 et 2. Les exercices peuvent se réaliser en autonomie grâce aux instructions méthodologiques détaillées et aux nombreuses illustrations. En plus des exercices en tant que tels de nombreuses ressources complémentaires sont proposées (sites web, applications). [less ▲]

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See detailTravaux Pratiques de Télédétection Spatiale I
Denis, Antoine ULiege

Learning material (2020)

Ce manuel était (avant 2020) le support principal des travaux pratiques de télédétection spatiale du cours de télédétection spatiale dispensé sur le Campus d’Arlon Environnement, Université de Liège ... [more ▼]

Ce manuel était (avant 2020) le support principal des travaux pratiques de télédétection spatiale du cours de télédétection spatiale dispensé sur le Campus d’Arlon Environnement, Université de Liège, Belgique. Ce manuel est téléchargeable gratuitement à l’adresse web : http://orbi.ulg.ac.be/handle/2268/143553. Les données associées à ces travaux pratiques sont disponibles ici https://dox.uliege.be/index.php/s/boXXpcD8FSkPOOn (confer section 4.1 page 22 du manuel). Le logiciel principalement utilisé dans le cadre de ces TP est un logiciel payant (ENVI, de la firme L3HARRIS GEOSPATIAL). Les autres logiciels/applications utilisés sont gratuits et disponibles sur le web: TIMESAT, ViewSpecPro et Google Earth notamment. Les exercices concernent, par ordre d'importance: la classification supervisée d'une image haute résolution (observation 2D et 3D, identification des zones d'entrainement et caractérisation statistique des échantillons, classification, validation), l'analyse diachronique de 2 images NDVI basse résolution (analyse de changement), l'analyse temporelle de séries d'images basses résolution (profil NDVI) et la caractérisation des saisons de végétation, la création de néo-canaux (NDVI, Tasseled cap, ACP,…), la correction géométrique d’une image (géoréférencement), l'analyse de données hyperspectrales (image et donnée ponctuelle), la découverte de Google Earth Pro, la recherche d'images satellites sur le web, la présentation de quelques exemples d’applications de la télédétection spatiale pour la gestion des risques et des catastrophes,… [less ▲]

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See detailInitiation à QGIS avec QGIS 3.10.0 - Travaux pratiques sur les Systèmes d'Information Géographique - SIG
Denis, Antoine ULiege

Learning material (2020)

This manual (in French) is an introduction to QGIS with data needed provided. It is freely available here: http://hdl.handle.net/2268/190559 Objectives of this manual are: 1. To give you a global view and ... [more ▼]

This manual (in French) is an introduction to QGIS with data needed provided. It is freely available here: http://hdl.handle.net/2268/190559 Objectives of this manual are: 1. To give you a global view and understanding of what a GIS is and what it is useful for 2. To introduce you to manipulation and processing of geographic data with the free QGIS software The vast majority of this manual is composed of exercises contextualized on the thematic of developing countries, environment management, and natural risk management. [less ▲]

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See detailWeather-Based Predictive Modeling of Wheat Stripe Rust Infection in Morocco
El Jarroudi, Moussa ULiege; Lahlali, Rachid; Kouadio, Louis et al

in Agronomy (2020), 10(2), 1-18

Predicting infections by Puccinia striiformis f. sp. tritici, with su cient lead times, helps determine whether fungicide sprays should be applied in order to prevent the risk of wheat stripe rust (WSR ... [more ▼]

Predicting infections by Puccinia striiformis f. sp. tritici, with su cient lead times, helps determine whether fungicide sprays should be applied in order to prevent the risk of wheat stripe rust (WSR) epidemics that might otherwise lead to yield loss. Despite the increasing threat of WSR to wheat production in Morocco, a model for predicting WSR infection events has yet to be developed. In this study, data collected during two consecutive cropping seasons in 2018–2019 in bread and durum wheat fields at nine representative sites (98 and 99 fields in 2018 and 2019, respectively) were used to develop a weather-based model for predicting infections by P. striiformis. Varying levels of WSR incidence and severity were observed according to the site, year, and wheat species. A combined e ect of relative humidity > 90%, rainfall 0.1 mm, and temperature ranging from 8 to 16 C for a minimum of 4 continuous hours (with the week having these conditions for 5% to 10% of the time) during March–May were optimum to the development of WSR epidemics. Using the weather-based model, WSR infections were satisfactorily predicted, with probabilities of detection 0.92, critical success index ranging from 0.68 to 0.87, and false alarm ratio ranging from 0.10 to 0.32. Our findings could serve as a basis for developing a decision support tool for guiding on-farm WSR disease management, which could help ensure a sustainable and environmentally friendly wheat production in Morocco. [less ▲]

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See detailEmploying Weather-Based Disease and Machine Learning Techniques for Optimal Control of Septoria Leaf Blotch and Stripe Rust in Wheat
El Jarroudi, Moussa ULiege; Lahlali, Rachid; El Jarroudi, Haifa et al

in Advanced Intelligent Systems for Sustainable Development (2020)

Septoria tritici blotch (STB) is among the most important crop diseases causing continuous threats to wheat production worldwide. STB epidemics are the outcome of interactions between susceptible host ... [more ▼]

Septoria tritici blotch (STB) is among the most important crop diseases causing continuous threats to wheat production worldwide. STB epidemics are the outcome of interactions between susceptible host cultivars, favorable environmental conditions, and sufficient quantities of pathogen inoculum. Thus, to determine whether fungicide sprays should be applied to prevent the risk of epidemics that might otherwise lead to yield loss, weatherbased systems as stand-alone or combined with other disease or agronomic variables have been implemented in decision-support systems (DSS). Given the economic importance of wheat in Morocco and increasing concerns caused by fungal plant pathogens in wheat-growing regions, DSS integrating a disease risk model would help to limit potentially harmful side effects of fungicide applications while ensuring economic benefits. Here we describe the use of an artificial intelligence algorithm, i.e. the artificial neural network, within a weatherbased modelling approach to predict the progress of STB in wheat in Luxembourg. The reproducibility of area-specific modelling approaches is often a hurdle for their application in operational disease warning system at a regional scale. Hence, we explore the potential of coupling artificial intelligence algorithms with weather-based model for predicting in-season progress of a major economically important fungal disease – wheat stripe rust – in selected wheatproducing regions in Morocco. [less ▲]

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See detailRevue des modes de représentation de l'information spatiale
Denis, Antoine ULiege

Learning material (2020)

Cette revue, en format diaporama, a pour objet de présenter de manière relativement exhaustive et synthétique les différents modes de représentation de l’information spatiale. Bien qu’elle se concentre ... [more ▼]

Cette revue, en format diaporama, a pour objet de présenter de manière relativement exhaustive et synthétique les différents modes de représentation de l’information spatiale. Bien qu’elle se concentre essentiellement sur l’aspect formel des représentations, leur aspect fonctionnel est aussi parfois considérés. [less ▲]

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See detailQGIS Universe - Illustration presenting the global organisation of QGIS 3.10 main components and functionalities
Denis, Antoine ULiege

Learning material (2019)

Illustration presenting the global organisation of QGIS 3.10 main components and functionalities. ! Diagram not validated !

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See detailL'univers QGIS - Illustration présentant l'organisation globale des principaux constituants et fonctionnalités de QGIS 3.10
Denis, Antoine ULiege

Learning material (2019)

Illustration présentant l'organisation globale des principaux constituants et fonctionnalités de QGIS 3.10. Schéma non validé.

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See detailAdapted transcription of the tutorial video “ESA Echoes in Space - Hazard: Flood mapping with Sentinel-1 (ESA EO College), by Chris Stewart, 5 November 2017” Augmented with additional illustrations and comments.
Denis, Antoine ULiege

Learning material (2019)

This document is an adapted transcription of the tutorial video (YouTube channel “EO College”) entitled « ESA Echoes in Space - Hazard: Flood mapping with Sentinel-1 (ESA EO College)” from 5 November 2017 ... [more ▼]

This document is an adapted transcription of the tutorial video (YouTube channel “EO College”) entitled « ESA Echoes in Space - Hazard: Flood mapping with Sentinel-1 (ESA EO College)” from 5 November 2017 where Dr. Chris Stewart explains how to derive a flood map from Sentinel-1 images, using SNAP. The transcription is augmented with additional illustrations and comments. The video tutorial is available here: https://www.youtube.com/watch?v=derOXkPCH80 [less ▲]

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See detailManuel de formation SIG sous QGIS 3.8.1 à destination de l’Association Intercommunale des Eaux du Condroz (AIEC)
Denis, Antoine ULiege

Learning material (2019)

L’Association Intercommunale des Eaux du Condroz (AIEC - http://www.eauxducondroz.be/) a en charge la production et la distribution d'eau potable dans le Condroz (Belgique) dans les 5 communes de Ciney ... [more ▼]

L’Association Intercommunale des Eaux du Condroz (AIEC - http://www.eauxducondroz.be/) a en charge la production et la distribution d'eau potable dans le Condroz (Belgique) dans les 5 communes de Ciney, Hamois, Havelange, Hotton et Somme-Leuze. L’AIEC est notamment amenée à cartographier les canalisations d’eau et divers éléments du réseau d’eau et à le positionner en prenant comme référence le Projet Informatique de Cartographie Continue (PICC) de la Wallonie. Ce manuel a pour vocation de guider les techniciens de l’AIEC dans leur prise en main du logiciel de cartographie libre QGIS pour mener à bien leur mission de cartographie. Les concepts et manipulations de données utiles aux techniciens de l’AIEC sont listés dans la table des matières de ce manuel. [less ▲]

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See detailLes drones Un nouvel eldorado pour les scientifiques et les entrepreneurs?
Heidarian Dehkordi, Ramin ULiege; Denis, Antoine ULiege

Scientific conference (2018, December 13)

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See detailCan satellites help organic crops certification?
Denis, Antoine ULiege

Doctoral thesis (2018)

Organic agriculture products are in increasing demand globally principally because, compared to conventional products, organic food is seen to be healthier and organic farming is more respectful of the ... [more ▼]

Organic agriculture products are in increasing demand globally principally because, compared to conventional products, organic food is seen to be healthier and organic farming is more respectful of the environment by avoiding the use of synthetic chemical fertilizers and pesticides, and it excludes genetically modified organisms. Organic labelled farming products have to comply with established international standards and rules, and, in particular, organic producers have to be certified annually by organic certification bodies. One of the challenges of this certification process is the efficient targeting of the relatively small percentage of fields declared to be organic that must effectively be subject to an in situ inspection. The main objective of the present research, the first of its kind, is to assess how spatial remote sensing may support the organic crop certification process. This research is based on the hypothesis that the differences in treatments between organically and conventionally managed crop fields, primarily the differences in fertilization and crop protection, would result in biochemical and biophysical differences between the fields. Among these differences, some are supposed to be observable by spatial remote sensing derived indices. Consequently, these indices could be used at the beginning of the field certification process to target for priority in situ control fields declared as organic but that would show on satellite imagery an appearance that is closer to conventional fields. Such a technique would provide organic certification bodies with a supplementary and independent means of control which might be particularly useful for large farms and in production regions located in remote areas where the certification process might be more difficult and costly. In order to address this objective, 3 case studies were elaborated. The first case study focuses on wheat and maize in central-eastern Germany and consists of an exploratory approach combining a wide range of both in situ measurements and satellite sensors of various spatial and spectral resolutions. The second case study has a main purpose to assess the robustness of the method developed in the first case study over years and regions. It consisted in repeating the method on the German study site for the following cropping season for wheat and maize, and, for wheat exclusively, on a region located in central France. Near operational conditions were simulated by a limited use of satellite images. The third case study focuses on organic cotton in Burkina Faso and has a primary purpose of assessing the method’s efficiency in the context of a developing country where rural areas are sometimes more difficult to reach, making the use of remote sensing particularly relevant. Results show that the efficiency of the proposed method varies greatly depending on the situation. Indeed, in some situations, it appeared that biochemical and biophysical differences between organically and conventionally managed fields may exist at given crop growth stages and are sufficiently pronounced to enable a complete discrimination between organic and conventional management modes through various simple indices derived from multispectral satellite images. In other situations however, the discrimination appeared to be far more difficult and required the complementarity of different types of indices integrated in multivariate linear models. Given these mixed results and the limited representativeness of the 3 case studies compared to the diverse contexts where the developed method is supposed to be used in operationally, it appeared that there is simultaneously both room for optimism but also considerable uncertainty with regard to whether spatial remote sensing could effectively contribute to ensuring that crop fields declared as organic are truly organic. [less ▲]

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See detailTélédétection pour le suivi des cultures et la sécurité alimentaire
Vrieling, Anton; Pini, Giancarlo; Tapela, Mataba et al

Learning material (2018)

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See detailLivret - Guide. Voyage d'étude dans l'Oriental marocain
Denis, Antoine ULiege

Learning material (2018)

Ce document est utilisé comme livret-guide d'un voyage d’étude d'une semaine dans l'Oriental marocain et a pour thème la gestion de l'environnement. Ce voyage est organisé dans le cadre du Master ... [more ▼]

Ce document est utilisé comme livret-guide d'un voyage d’étude d'une semaine dans l'Oriental marocain et a pour thème la gestion de l'environnement. Ce voyage est organisé dans le cadre du Master Complémentaire en Sciences et Gestion de l’Environnement dans les Pays en Développement de l'Université de Liège. Ce livre guide contient essentiellement un résumé de toutes les problématiques environnementales abordées au cours du voyage (station d'épuration de l'eau, décharges, dégradation des sols et désertification, reboisement, parc naturel, gestion d'une oasis, aménagement du litoral, etc. [less ▲]

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See detailLandings profile of small-scale fisheries in Senegal: The case of the Kayar Marine Protected Area
Gueye, Ndiapaly; Diop, Mamadou; Denis, Antoine ULiege et al

Poster (2015, October 08)

As marine fisheries in Senegal are in serious decline due to overexploitation, the management of sustainable fisheries requires effective tactics based on scientific data. In order to characterize the ... [more ▼]

As marine fisheries in Senegal are in serious decline due to overexploitation, the management of sustainable fisheries requires effective tactics based on scientific data. In order to characterize the current state of the artisanal fishery of the Kayar Marine Protected Area (MPA), a daily survey of fish landings was carried out between October 2013 and May 2015, and a database was created. Results showed that the landings are largely dominated by pelagic species in terms of weight. In total, 84 taxa were registered, including the species Sardinella aurita, which has been the most landed (30.5%), followed by Trichiurus lepturus (18.9%). These species are mainly captured by means of purse seine. The other types of fishing gear used in the area are the long line and the single line, which target particular species (e.g., Epinephelus aeneus). The temporal evolution of landings shows a period of abundance between May and June, while fishing effort is generally increasing. Regarding the spatial distribution, landings originate primarily from the MPA, where the landing per unit of effort was higher in the Angleterre area compared to other studied areas. These temporal and spatial variations seem to be related to the upwelling intensity which is highly seasonal, habitat features (i.e., presence of an underwater canyon in the MPA), the ecological behaviour of fish species and overexploitation. Our results confirm the need for detailed and extensive population monitoring across fish species. As a result of this study, we hope to provide the first essential information for the integrated management of fisheries in the Kayar MPA and its surrounding area. [less ▲]

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See detailMyEorganics ! Where it goes?
Denis, Antoine ULiege

Conference given outside the academic context (2015)

Oral contribution to the "Mobile Applications for Agriculture" workshop. Description of the workshop: The myEOrganics project: Challenges and opportunities of space based services for certification July ... [more ▼]

Oral contribution to the "Mobile Applications for Agriculture" workshop. Description of the workshop: The myEOrganics project: Challenges and opportunities of space based services for certification July 2nd, 2015, 12:30 – 17:30h, Park Inn By Radisson Liege Airport Hotel - Rue de l'Aéroport 14, 4460 Grâce-Hollogne INFOPOLE Cluster TIC would like to kindly invite you in the name of the myEOrganics consortium to the “Mobile Applications for Agriculture” Workshop. This Workshop shall support the development and implementation of the myEOrganics service and analyses technical and policy requirements for this business case in general. myEOrganics supports the auditing procedure of organic agriculture by providing information on several indicators, like nitrogen level in plants, field shape, etc. to auditors on a mobile app. The necessary information is derived from processed Earth Observation (EO) satellite data and enables the auditor to determine whether a field is being cultivated according to standards of organic farming or not, thus making the distinction between non-organically (i.e. conventionally) and organically grown crop. With the help of geo-referencing, this data can be used in-situ on a mobile device capable of geo-positioning by certification personnel during their audits. This Stakeholder Workshop within the myEOrganics project is targeted towards experts from different areas of organic farming, certification, satellite data management and processing, as well as related topics. myEOrganics and its business case will be discussed in order to identify potentials and barriers of its implementation, further discussions will take place to analyze the general potential of alike business cases (mobile satellite data based services for agriculture). [less ▲]

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See detailMyEorganics ! Where it comes from?
Denis, Antoine ULiege

Conference given outside the academic context (2015)

Oral contribution to the "Mobile Applications for Agriculture" workshop. Description of the workshop: The myEOrganics project: Challenges and opportunities of space based services for certification July ... [more ▼]

Oral contribution to the "Mobile Applications for Agriculture" workshop. Description of the workshop: The myEOrganics project: Challenges and opportunities of space based services for certification July 2nd, 2015, 12:30 – 17:30h, Park Inn By Radisson Liege Airport Hotel - Rue de l'Aéroport 14, 4460 Grâce-Hollogne INFOPOLE Cluster TIC would like to kindly invite you in the name of the myEOrganics consortium to the “Mobile Applications for Agriculture” Workshop. This Workshop shall support the development and implementation of the myEOrganics service and analyses technical and policy requirements for this business case in general. myEOrganics supports the auditing procedure of organic agriculture by providing information on several indicators, like nitrogen level in plants, field shape, etc. to auditors on a mobile app. The necessary information is derived from processed Earth Observation (EO) satellite data and enables the auditor to determine whether a field is being cultivated according to standards of organic farming or not, thus making the distinction between non-organically (i.e. conventionally) and organically grown crop. With the help of geo-referencing, this data can be used in-situ on a mobile device capable of geo-positioning by certification personnel during their audits. This Stakeholder Workshop within the myEOrganics project is targeted towards experts from different areas of organic farming, certification, satellite data management and processing, as well as related topics. myEOrganics and its business case will be discussed in order to identify potentials and barriers of its implementation, further discussions will take place to analyze the general potential of alike business cases (mobile satellite data based services for agriculture). [less ▲]

Detailed reference viewed: 40 (3 ULiège)