Sökning: "nitrogen budget"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden nitrogen budget.

  1. 1. 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

  3. 2. 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

  4. 3. Silicon cycling in the Baltic Sea : Trends and budget of dissolved silica

    Författare :Liana Papush; Åsa Danielsson; Lars Rahm; Petra Tallberg; Linköpings universitet; []
    Nyckelord :Dissolved silica; trends; nutrient; nutrient ratios; diatoms; Redfield; limitation; eutrophication; riverine load; budget; fluxes; accumulation; retention; optimisation; Baltic Sea; Löst kisel; trender; näringsämne; näringsämnens kvoter; kiselalger; Redfield; tillväxtbegränsning; övergödning; flodtillförsel; budget; flöden; ackumulering; retention; optimering; Östersjön; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : The dissolved silicon (DSi) has a crucial role for growth of a large group of primary producers – diatoms and, hence, impact on functioning of the aquatic food web. This thesis contributes to an increased understanding of the modifications of the DSi cycling in the Baltic Sea. LÄS MER

  5. 4. Nutrient cycling in agroecosystems: nitrogen cycling in southern Sweden in the 1850s and two Tanzanian villages in the 1990s

    Författare :Lars-Erik Williams; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nutrient; nutrient model; nutrient cycling; nitrogen fixation; nitrogen budget; mixed system; miombo; manure; livestock; land use; historical system; food production; efficiency; crops; agroecosystem; carrying capacity; phosphorus; Scania; sustainability; Plant ecology; Växtekologi;

    Sammanfattning : This study presents a general model for analysing nutrient cycling in agroecosystems. The focus is on food production intensity, human carrying capacity, sustainability and efficiency. The model can be used on systems including different kinds of land uses, which makes it applicable for studies on different scales. LÄS MER

  7. 5. Agricultural nutrient budgets in Europe: data, methods, and indicators

    Författare :Rasmus Einarsson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Europe; EU; indicators; agriculture; nutrient balance; environment; nitrogen; nutrient budget; phosphorus;

    Sammanfattning : Agricultural production systems feed humanity but also cause a range of adverse environmental effects, including climate change, loss of biodiversity, and pollution of air and water. A main cause of these effects is the emissions of nitrogen (N) and phosphorus (P) that occur as a side effect of nutrient cycling in agriculture. LÄS MER