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The pig production in walloon region exists in different forms. The conventional production exists side by side with some productions of "differentiated qualities" that are encouraged as much by the European Union as by the Walloon Region. At the same time, the EU and the Walloon Region are imposing environmental limitations concerning the management of nitrogen, the respect to the residents... Differentiated quality and the respect of the environment seem to be linked implicitly, but no demonstration of this exists for the pig production. The object of the present survey was to compare the nitrogen balances, the atmospheric emissions and the distance of odour diffusion for the conventional production, organic production and the production "fermier". This is taking into account the real process performances of the farms, existing legislation, the opinion of a jury of experts on the relative importance of the atmospheric emissions of pig production and the political objectives of the Region they are situated in. This survey is based on 21 farms, which are organised into three categories. These farms have been audited with the software "Ecoferme". The nitrogen fluxes and the nitrogen balance within these exploitations were simulated. The atmospheric emissions and the distance of odour diffusion were estimated as well. A jury of 16 experts was formed, which was composed of four poles : a scientific pole, a pole of public proxies and administrations, a pole of producers and a pole of the third party (citizens, neighbours,...). This jury was questioned according to a Delphi method (individually and repetitively) to assign a relative importance to the emissions of ammonia, greenhouse gases, molecular nitrogen and odour. The most important weighting was assigned to the odour diffusion, the emission of ammonia came next, then the emissions of greenhouse gas and finally the emission of molecular nitrogen got a weak weighting. Some criteria have been constructed to charact erize the performances of the farms, which take into account of the spreading of organic nitrogen and the commitment taken by the Region to follow the protocols of Kyoto and Gothenburg. The comparison of the process performances was achieved by means of the method of multicriteria analysis Electre III, which was applied to the global averages. The relative ordering obtained was : organic production, production "fermier" and conventional production. However within every sample an important variability of the performances was observed. The same method applied within every sample enables the creation of subgroups, working according to the same specifications but with weak, middle and good performances. The application of the ordering method to the nine subgroups shows that the most effective exploitations of every system of production are classified as top of the class. Thus, on average, the production of differentiated qualities are more environmentally effective than the conventional pr oduction but the variability of the performances within a system of production is important and it is quite possible for the conventional exploitations to reach some results comparable to those of the best organic and "fermier" exploitations.

Swine --- Intensive husbandry --- animal husbandry methods --- Environmental impact --- Nitrogen --- nitrogen cycle --- Animal feeding --- Pollution --- surveys --- Regulations --- evaluation. --- evaluation --- methodology --- Wallonie --- Ecoferme --- Methode delphi

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Piggeries --- air pollution --- Slurry --- storage --- Fertilizer application --- Animal housing --- design --- Aeration. --- Aeration --- Animal feeding --- Pollution --- surveys --- Models --- Cost analysis

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In recent decades, agriculture is challenged to develop strategies for sustainability which conserve non-renewable natural resources such as soil. Soil improving conservation systems aim at improving soil functions and at the same time ensuring high productivity. Such soil management systems have to be adapted to climate and soil specific conditions, and may include reduced tillage, balanced crop rotation, retention of crop residues, cover crops, and appropriate timing of field operations. Changes in soil functions have huge impacts on environmental flows like hydrology, crop production, solute transfer, and CO2 emission at macroscale. Soil structure is considered as one of the key factors for soil functioning. The effect of different land management on soil structure and consequently on soil hydrodynamics is not fully understood and still under investigation. The main aim of this thesis was to evaluate the effect of crop residue management on soil structure by measuring soil hydraulic properties in pedon and core scale. The agronomic context was different crop residue management in a reduced tillage system. The experimental field is named as Solresidus located in Gembloux, Belgium. Since 2008, the field has been under conservation system. Different residue management includes reduced tillage with incorporation of crop residues (RT-in) and without incorporation (RT-out). A large part of this thesis was methodological development to obtain accurate results from experimentations. Many studies have been made and documented in literature to develop indirect methods to predict soil hydrology from soil water retention curve (SWRC). There is no measuring device available which can determine the SWRC over the entire soil moisture range. Therefore, one of the methodological developments was to obtain complete SWRC by combining three different methods in core scale: X-ray computed microtomography (X-ray CT), HYPROP evaporation and Richards pressure plate method to obtain the entire SWRC. The combination of these methods found well justified to obtain the accurate and complete SWRC. Saturated hydraulic conductivity (Ks), specific connectivity (SC) of soil pores and bulk density of the soil were also measured in core and pore scale. There were soil moisture sensors (capacitance sensors) in the field to observe the soil moisture dynamics in pedon scale. Another important methodological development was to obtain the calibration results with the moisture sensor according to the soil texture and horizons. Calibration results found quite satisfying to get the accurate moisture content of the field; it was also noticed that it could be over estimation of soil moisture without the calibration. Significantly, average higher moisture content was observed by the moisture sensors in RT-in than RT-out during the canopy formation to harvest of winter wheat in 2014. The SWRCs also showed that plant available water content was higher in RT-in than RT-out. SC of soil pores was also significantly higher at the surface soil of RT-in than RT-out. RT-in found to have significant positive effects on soil structure by reducing bulk density, increasing SC, Ks and retention of soil moisture during the observation period of this study. Crop yield was marginally higher and organic matter content was significantly higher in RT-in than RT-out (results from close collaboration). Therefore, reduced tillage with residues incorporation found to have better soil hydraulics together with better crop yield than reduced tillage without incorporation of crop residues.

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Au Burkina Faso, face à la persistance des aléas climatiques qui compromettent la production agricole essentiellement pluviale, le développement de l'irrigation est apparu comme une alternative porteuse pour sécuriser, intensifier et accroitre durablement la production agricole. Cependant, l'une des principales contraintes au développement de l'irrigation est la disponibilité en eau, la rareté ou le manque d'eau dans les zones irriguées. La présente recherche a contribué à la réflexion sur la problématique de l'eau sur les périmètres irrigués au Burkina Faso à travers l'évaluation des indicateurs de performances techniques, l'analyse de la gestion de l'irrigation et l'efficacité organisationnelle des irrigants, tout en examinant préalablement le contexte général du développement de l'irrigation. L'étude montre qu'il tombe globalement des quantités d'eau relativement importantes au Burkina Faso. Cependant, la répartition de cette eau dans le temps et dans l'espace est très aléatoire et ne permet pas de garantir une bonne campagne agricole de saison humide. La mise en œuvre de techniques de collecte des eaux de ruissellement et la pratique de l'irrigation d'appoint permettraient de sécuriser davantage la production agricole de saison humide. Ce contexte pluviométrique aléatoire justifie le choix des producteurs et des politiques de développer l'agriculture irriguée. L'irrigation au Burkina Faso est essentiellement gravitaire et est faiblement développée, avec 33 % de superficies aménagées sur un potentiel irrigable de233500 ha. Des efforts sont consentis dans la réalisation des ouvrages pour l'irrigation. Cependant, le pilotage de l'irrigation est peu maîtrisé et les producteurs peu organisés pour assurer la bonne gestion de l'eau et l'entretien des ouvrages hydrauliques. Par ailleurs, si l'eau utilisée pour l'irrigation ne présente aucun risque pour les cultures et le sol pour l'instant, une mauvaise gestion des engrais et des pesticides a été mise en exergue, ce qui pourrait avoir des conséquences négatives sur l'environnement à plus ou moins long terme. Afin d'évaluer les performances techniques des périmètres irrigués, une synthèse bibliographique a permis de passer en revue et d'éclaircir davantage les concepts d'efficience et de productivité de l'eau selon leurs domaines d'application ainsi que les systèmes d'irrigation et les outils à mettre à contribution dans le pilotage efficient de l'irrigation. Les résultats de l'évaluation des performances techniques des périmètres irrigués de Savili et de Mogtédo, montrent que l'efficience d'application de l'eau est inférieure à 20 % à Savili et comprise entre 41 et 55 % à Mogtédo. La productivité de l'eau varie de 1,12 à 3,4 kg m-3 pour Allium Cepa (oignon) à Mogtédo et à Savili, 0,31 kg m-3 pour Zea mays (maïs) à Mogtédo et 0,34 kg m-3pour Phaseolus vulgaris (haricot vert) à Savili. La modélisation des calendriers théoriques et réels d'irrigation montre que par rapport au calendrier théorique d'irrigation, le calendrier réel d'irrigation des périmètres formels et informels présentait des irrigations trop fréquentes et abondantes, les cultures recevant de l'eau avant d'avoir épuisé les réserves en eau disponibles. Une mauvaise gestion de l'irrigation a entraîné une perte d'eau importante, estimée à 2 999 923 m3 / an pour les sites de Mogtédo et Savili. La raison principale de cette contre-performance semble être liée aux faiblesses techniques et organisationnelles des producteurs. Cette étude a mis en évidence le gaspillage de l'eau pour l'irrigation et la forte concurrence entre les périmètres formels et informels. Ainsi, le problème de l'eau sur les périmètres irrigués au Burkina Faso n'est pas directement lié au manque d'eau mais surtout à sa mauvaise gestion. L'amélioration des performances des périmètres irrigués autour des petits réservoirs pourrait nécessiter de : - renforcer les capacités techniques, organisationnelles et opérationnelles des agriculteurs ; - améliorer la qualité technique des aménagements parcellaires ; - privatiser l'approvisionnement en eau des périmètres irrigués, de sorte que l'agriculteur bénéficie du service de l'eau.