Mise en évidence des émissions ammoniacales issues des épandages de lisier en Bretagne

[Departement_IRSTEA]EEE [TR1_IRSTEA]E33-Maîtrise et gestion des déchetsThis paper presents results obtained during four field experiments carried out in Brittany in 1993. Ammonia losses through volatilization following pig slurry spredaing were measured using the wind tunnel method. Volatilization curves analysis showed the importance of losses during the few first hours following spreading . Cumulative ammonia losses within the first 6 hours were well correlated to the rates of ammoniacal-N applied. It appared that ammonia flux densities were adjusted to the day-nigh fluctuations of air temperature. Water applied (equivalent to 60% in volume of the slurry applied) reduced ammonia emission by 32%.Cet article expose les résultats de mesures d'émissions ammoniacales liées aux épandages de lisiers obtenus lors de 4 essais au champ réalisés en Bretagne en 1993. Après épandage de lisier de porc, les pertes d'ammoniac par volatilisation ont été mise en évidence et quantifiées au moyen de tunnels de ventilation.. L'analyse des courbes de volatilisation souligne l'importance du processus durant les premières heures qui suivent l'épandage. L'analyse des résultats a également montré que les pertes mesurées lors des 6 premières heures étaient étroitement corrélées à la dose d'azote apportée. Le processus de volatilisation mis en évidence lors de cet essai suit des variations nycthémérales identiques aux fluctuations de température de l'air. L'apport d'eau supplémentaire, à hauteur de 60% de l'apport de lisier, a entraîné une diminution de 32% des pertes d'ammoniac par volatilisation

Etude de la volatilisation de l'azote des lisiers de porcs. Recherche des moyens pour la prévenir et la limiter

A study on ammonia volatilisation studies was developped based on two approaches : - the study of the external factors on this process of losses (temperature air, soil, wind speed...) ; - the study of the internal factors from slurry composition (ph, TS, VFA...). / Une étude sur la volatilisation de l'azote ammoniacal des lisiers a été réalisée en distinguant deux aspects liés à la quantification et à la maîtrise de ce processus : l'étude des facteurs physiques externes (climatiques, température, vitesse, vent...) ; - l'étude des facteurs physico-chimiques internes au lisier (ph, teneur en M.S., teneur en AGV...). L'impact de l'azote ammoniacal apporté par le lisier sur l'azote du sol sous toutes ses formes (NO3, n-organique) a été abordé

Mises au point méthodologiques concernant l'utilisation de "wind tunnel" pour la mesure des émissions ammoniacales consécutives aux épandages de lisier

In agricultural research, particularly when it comes to field experiments and when the results may have regulatory consequences, it is important to ensure the reliability of the methods used to obtain them. Intercomparative projects such as those mentioned in this article will have to be encouraged. / Dans le domaine de la recherche en agriculture, notamment lorsqu'il s'agit d'essais terrain, et lorsque les résultats sont susceptibles d'avoir des répercussions "réglementaires", il est important de s'assurer de la fiabilité des méthodes mises en oeuvre pour les obtenir. Les travaux d'intercomparaisons tels ceux faisant l'objet de ce rapport, doivent donc être encouragés

Ammonia volatilization following surface-applied pig and cattle slurry in France

Field experiments were carried out in Brittany (Western France) in 1993 to measure ammonia losses from surface-applied pig and cattle slurry. On average, 75% of the total loss in all experiments occured within the first 15 h after spreading. Significant correlations were found between ammonia loses (KgN /ha) and mean soil temperature and slurry dry matter content (%) using simple linear regessions and stepwise procedures. / Une série d'essais au champs ont été conduits en Bretagne au cours de l'année 1993 pour mesurer les émissions d'ammoniac après épandage de lisier bovin et porcin. En moyenne 75% des pertes totales sont enregistrées au cours de 15 heures suivant l'épandage. Des corrélations significatives ont été observées entre les pertes d'ammoniac (en KgN/ha) et la température moyenne du sol et la teneur en matière sèche du lisier

Contribution du traçage isotopique 15N à l'étude du devenir des émissions azotées gazeuses du lisier

15N tracer techniques are usually recognised as a unique tool to follow nitrogen turn-over from soil-plant studies, particularly from nitrogen fertilizer applications, they remain poorly documented in studying losses from animal manures. Direct labelling of animal manure with 15N is possible by incorporating 15N into animal feed, but is very expensive, labor intensive and time consuming. It is however particularly relevant when the organic N fraction is investigated. More frequently, authors labelled the NH4+-N pool of a slurry by adding a small amount of highly enriched NH4+-N. Moal et al conducted a preliminary study that demonstrated that the added N behaves as the endogenous NH4+ initially present in the slurry. This abstract describes field and laboratory 15N balance studies conducted to determine the fate of labelled ammonium sulphate into a pig slurry.L'utilisation de l'isotope stable 15N est largement répandue pour l'étude du devenir de l'azote - dans le système sol-plante - des fertilisants chimiques. Peu d'études ont été conduites pour l'étude du devenir de l'azote des lisiers à l'aide de l'outil isotopique. Ce résumé illustre différentes applications du traçage isotopique 15N pour l'étude du devenir de l'azote des lisiers, à la fois des émissions d'ammoniac après épandage et des processus de nitrification dénitrification

Ammonia volatilization following surface-applied pig and cattle slurry in France

Field experiments were carried out in Brittany (Western France) in 1993 to measure ammonia losses from surface-applied pig and cattle slurry. On average, 75% of the total loss in all experiments occured within the first 15 h after spreading. Significant correlations were found between ammonia loses (KgN /ha) and mean soil temperature and slurry dry matter content (%) using simple linear regessions and stepwise procedures. / Une série d'essais au champs ont été conduits en Bretagne au cours de l'année 1993 pour mesurer les émissions d'ammoniac après épandage de lisier bovin et porcin. En moyenne 75% des pertes totales sont enregistrées au cours de 15 heures suivant l'épandage. Des corrélations significatives ont été observées entre les pertes d'ammoniac (en KgN/ha) et la température moyenne du sol et la teneur en matière sèche du lisier

Marquage de l'azote du lisier de porc par ajout direct de sulfate d'ammonium : une expérience en laboratoire de la volatilisation de NH3

International audienceThe addition of exogenous ammoniacal nitrogen to slurry can be used to study the influence of ammoniacal nitrogen concentration or the presence of different ions on ammonia emissions. This preliminary study aimed to test the validity of such a direct incorporation of ammonium salts to slurries in relation to ammonia volatilization. It was conduted using cylindrical glass volatilization chambers an 15N-labelling techniques. Labelled pig slurry was prepared by direct addition of 15N-(NH4)2SO4(15N-AS). The fate of total ammoniacal nitrogen was followed for 48 h from surface application to soil. The analysis of isotopic excess (E%) of volatilized ammonia 0.25, 2, 6, 12, 24 and 48 h after labelled slurry application suggested that the added N4+ behaved as the endogenous NH4+ initially present in the slurry. An average TAN-15N (total ammoniacal nitrogen) recovery of 97.5% (CV 2%) was obtained. During this study, no immobilization or nitrification of slurry-derived nitrogen was noticed.Description d'une procédure de marquage de l'azote du lisier par ajout direct de sulfate d'ammonium enrichi en N15 au cours d'une étude cinétique de volatilisation de l'azote des lisiers

Evaluation of the wind-tunnel method for measurement of ammonia volatilization from land

A comparison was made of the percentage ammonia recovery from a UK and a French system of small wind-tunnels, commonly used for studying ammonia volatilization losses from grassland. Evaluation of wind-tunnel systems is necessary if data generated by this method are to be used for estimating ammonia losses form field-scale sites and if comparisons are to be drawn between results from different laboratories, organisation and countries. Indoor trials resulted in an average ammonia percentage recovery of 86 and 90% for the UK and French wind tunnel systems, respectively. The difference was probably related to the sampling procedure or to the calculation of the loss rather than to the real process of volatilization from the trays or to the small differences in equipment. Nevertheless, the results suggest that the ammonia trapping efficiency of the wind tunnel system should be evaluated on a regular basis. / Une campagne expérimentale a été conduite à la Station de Recherches de North-Wyke (Royaume-Uni). L'efficacité de deux systèmes de tunnels de ventilation (wind tunnel) a été comparée au cours d'essais de calibration en conditions contrôlées. Trois tunnels construits d'après le modèle de LOCKYER et utilisés régulièrement en France (Cemagref Rennes) ont été testés en regard de six "wind tunnels" développés et utilisés en routine par la station de North Wyke. En moyenne, le pourcentage de recouvrement des tunnels Français s'établit à 90% contre 86% pour les tunnels britanniques. Ces essais ont permis de confirmer que la méthodologie "wind tunnel" permet d'obtenir une mesure par défaut de la volatilisation, mais également que les deux systèmes de tunnels testés, fournissent des résultats comparables et fiables

Lipid composition of the giant lion's-paw scallop (Nodipecten subnodosus) in relation to gametogenesis: I. Fatty acids

cited By 37International audienceSeasonal variations in fatty acid composition in several tissues of a 1-year-old population of giant lion's-paw scallop Nodipecten subnodosus were analyzed during gonad development. Samples were taken bimonthly from December 1999 to June 2000, a period in which gonad development was occurring. Fatty acid accumulation in neutral and polar lipids of the female gonad was concomitant to the gonad development and presented a maximum in June. Among essential fatty acids, a specific accumulation was observed only for 20:5n - 3 in the female gonad, as suggested by an increase in its proportion in the neutral and the polar fractions. However, no specific accumulation was observed for 22:6n - 3, as its proportion remained relatively constant in both fractions. We suggest that a specific increase of 22:6n - 3 is not necessary during gametogenesis because its proportion was high enough for reproductive purposes (20-30%). Although some data suggest a partial mobilization of polyunsaturated fatty acids from the muscle and digestive gland to the female gonad during gonad development, the main supply came directly from the diet. The maximum increase in total and specific fatty acids in the digestive gland occurred in April and was maintained in June. These changes reflect either a higher lipid availability of the food, or the beginning of storage process in the digestive gland. However, in the female gonad, the maximum increase was observed in June, whereas gonad development and spawning were observed from April. It is suggested that different patterns of lipid accumulation in the first (April) and second (June) maturation processes could be related to the reproductive cycle of this species, which exhibits an initial facultative maturation during spring and the main reproductive activity during summer. © 2005 Elsevier B.V. All rights reserved