%0 Journal Article %J European Journal of Agronomy %D 2007 %T A whole-farm assessment of the efficacy of slurry acidification in reducing ammonia emissions %A Kai, P %A Pedersen, P %A jensen, J. E %A Hansen, M. N %A Sommer, S. G %K EPNB %X Livestock slurry in animal houses, in manure stores and applied on fields is in Denmark the most important source of ammonia (NH3) in the atmosphere. The emitted NH3 is a source of NH3 and ammonium (NH4 +) deposition, which causes eutrophication of N-deficient ecosystems and may form NH4 +-based particles in the air, which are a risk to health. This study examines the reductions in NH3 emissions from pig houses, manure stores and manure applied in the field achieved by acidifying the slurry in-house. Sulphuric acid was used to acidify pig slurry to pH < 6 and the system was constructed is such a way as to prevent foaming in the animal house as well as during storage. Acidification of the pig slurry reduced the NH3 emission from pig houses by 70% compared with standard techniques. Acidification reduced NH3 emission from stored slurry to less than 10% of the emission from untreated slurry, and the NH3 emission from applied slurry was reduced by 67%. The mineral fertilizer equivalent (MFE) of acidified slurry was 43% higher compared with the MFE of untreated slurry when applied to the soil. The odour emission from the slurry was not affected significantly by the treatment. The slurry acidification system is approved Best Available Technology (BAT) in Denmark. %B European Journal of Agronomy %V 28 %P 148-154 %1 General %0 Journal Article %J J. Limnol. %D 2008 %T The water chemistry of Northern Patagonian lakes and their nitrogen status in comparison with remote lakes in different regions of the globe %A Rogora, M %A Massaferro J. %A Marchetto A. %A Tartari G. A. %A Mosello R. %K Alps %K Antarctica %K atmospheric deposition %K Nepal %K Nitrate %X Eighteen small shallow lakes located in the Northern Patagonian Lake District, in southern South America, were sampled in 2001 and analysed for the main chemical variables (pH, conductivity, alkalinity, major ions and nutrients). The study lakes span a wide geographical and altitudinal range and belong partly to the Pacific and partly to the Atlantic watershed. The main aim of this study was to investigate the relationships between water chemistry and physical/geographical properties of these lakes. Secondly, the nitrogen content of the lakes was considered in detail, and results compared to those obtained in previous studies carried out in other remote areas of the globe (the Central Southern Alps in Italy, the Sierra da Estrela region in Portugal, the Svalbard Islands in the Arctic, the Khumbu-Himal region in Nepal, and the Terra Nova Bay area in Antarctica). In the Alps, lakes are characterised by markedly high nitrogen concentrations, manly as nitrate, due to the high inputs of nitrogen compounds from downwind sources like the Po Plain in Northern Italy. Conversely, lakes at remote locations such as the Andes, Antarctica and Himalaya are characterised by a low nitrogen content, mainly as organic nitrogen. This status is related to the limited atmospheric inputs of nitrogen affecting these regions. %B J. Limnol. %V 67 %P 75-86 %N 2 %1 General