Sökning: "nitrogen"

Visar resultat 1 - 5 av 1266 avhandlingar innehållade ordet nitrogen.

  1. 1. Marine nitrogen fixation : Cyanobacterial nitrogen fixation and the fate of new nitrogen in the Baltic Sea

    Författare :Isabell Klawonn; Helle Ploug; Lasse Riemann; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; biogeochemistry; nitrogen cycling; nitrogen fixation; cyanobacteria; Baltic Sea; Marine Ecology; marin ekologi;

    Sammanfattning : Biogeochemical processes in the marine biosphere are important in global element cycling and greatly influence the gas composition of the Earth’s atmosphere. The nitrogen cycle is a key component of marine biogeochemical cycles. LÄS MER

  3. 2. Assessing reactive nitrogen flows in European agricultural systems

    Författare :Rasmus Einarsson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; LANTBRUKSVETENSKAPER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; AGRICULTURAL SCIENCES; food; nitrogen indicator; nitrogen budget; nitrogen; agriculture; nitrogen footprint; uncertainties;

    Sammanfattning : In most ecosystems, nitrogen is a scarce and growth-limiting nutrient. Natural and anthropogenic processes convert unreactive atmospheric dinitrogen (N2) into reactive, bioavailable, nitrogen. LÄS MER

  4. 3. Nitrogen Losses from a Clay-rich Soil used for Cereal Production in south-western Sweden

    Författare :Magdalena Wallmann; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; nitrogen; fertilisers; soil; nitrous oxide; nitrogen leaching; 15N; nitrogen use efficiency; nitrogen budget; agriculture; Sweden;

    Sammanfattning : Addition of fertiliser nitrogen (N) in crop production increases yields and protein contents, but all is not taken up by the crop. Instead, some of the N is lost to air and waters, contributing e.g. to climate change, stratospheric ozone depletion, eutrophication and acidification. LÄS MER

  5. 4. Biological nitrogen fixation : the effect of irridiated nitrogen gas on nitrogen fixation by Azotobacter

    Författare :Bengt Zacharias; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  7. 5. Riverine nitrogen : Analysis and modelling under Nordic conditions

    Författare :Berit Arheimer; Linköpings universitet; []
    Nyckelord :SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

    Sammanfattning : The Baltic Sea in northern Europe is a brackish water body where eutrophication is considered a serious problem, partly as a result of high nitrogen load from rivers. This thesis includes statistical analysis of nitrogen behaviour in 55 small catchments. The results were used for further development of a dynamic model (HBV-N). LÄS MER