Sökning: "nitrogen fixation"

Visar resultat 16 - 20 av 80 avhandlingar innehållade orden nitrogen fixation.

  1. 16. Strategic nitrogen management in stockless organic cropping systems : redistribution of residual biomass for improved energy and nitrogen balance

    Författare :Tora Råberg; RISE; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; bioenergy; biomass management; crop rotation; ecological intensification; green manure; life cycle assessment; nitrogen cycling; organic agriculture; soil incubation; stockless cropping systems;

    Sammanfattning : A griculture faces the challenge of producing high yields to feed a growing world population, while simultaneously addressing environmental problems such as eutrophication, emissions of greenhouse gases, loss of biodiversity and soil degradation. Organic farming can be part of the solution, as it promotes biodiversity, uses less energy for fertiliser production and often has higher inputs of organic matter to soil than conventional farming. LÄS MER

  3. 17. Distribution and activity of nitrogen-fixing bacteria in marine and estuarine waters

    Författare :Hanna Farnelid; Lasse Riemann; Jonathan Zehr; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 454-pyrosequencing; diazotrophs; heterotrophic bacteria; marine bacteria; marine microbial ecology; microbiology; nifH; nitrogenase; nitrogen fixation; PCR; qPCR; Mikrobiologi; Microbiology;

    Sammanfattning : In aquatic environments the availability of nitrogen (N) generally limits primary production. N2-fixing prokaryotes (diazotrophs) can convert N2 gas into ammonium and provide significant input of N into the oceans. Cyanobacteria are thought to be the main N2-fixers but diazotrophs also include a wide range of heterotrophic bacteria. LÄS MER

  4. 18. Ammonia assimilation and nitrogen fixation in phototrophic bacteria : studies on glutamine synthease and the metabolic regulation of nitrogenase in Rhodospirillum rubrum

    Författare :Abdelhamid Soliman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The phototrophic bacteria and a few other species, are able to control nitrogen fixation on the metabolic level. This is a fast and reversible mechanism, which “switches off and on” the nitrogenase activity in response to the accessibility of combined nitrogen, the energy supply and the level of oxygen in the medium. LÄS MER

  5. 19. Nitrogen fixation associated with Sphagnum and some other musci

    Författare :Karl Basilier; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  7. 20. Electron transport to nitrogenase in Rhodospirillum rubrum

    Författare :Tomas Edgren; Stefan Nordlund; Patrick Hallenbeck; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Rhodospirillum rubrum; nitrogen fixation; electron transport; FixABCX; ferredoxin; Biochemistry; Biokemi;

    Sammanfattning : Biological nitrogen fixation is a key step in the global nitrogen cycle. In this process, dinitrogen in the air is converted to biologically accessible ammonia, which is further assimilated in to the biosphere. LÄS MER