Sökning: "Nutrient use efficiency"

Visar resultat 1 - 5 av 32 avhandlingar innehållade orden Nutrient use efficiency.

  1. 1. 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; 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

  3. 2. Nutrient use strategies of plants of various life-forms in a subarctic environment : Nutrient conservation as an adaption to infertile habitats

    Författare :Rolf Lutz Eckstein; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Mean residence time; Nutrient productivity; Nutrient use efficiency; Plant strategies; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Plant performance in relation to limiting nutrients was analysed using the concept of nutrient use efficiency (NUE). NUE can be decomposed into (1) the nutrient productivity (aNP) and (2) the mean residence time (MRT). LÄS MER

  4. 3. Soil phosphorus – a multidimensional resource that plays an important role for grassland plant species richness

    Författare :Jakob Sandberg; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; niche dimension; nutrient limitation; niche differentiation; competition; soil nitrogen; soil phosphorus; plant diversity; species richness; Grassland; land use; landscape scale;

    Sammanfattning : The semi-natural grassland habitats contain an important part of the plant diversity in Europe. Changes in farming practices have lead to drastic decreases in plant species richness. The aim of the present thesis is to contribute to the knowledge about mechanisms governing the plant species richness in grasslands with emphasis on soil nutrients. LÄS MER

  5. 4. Associations among early-season root and shoot traits, nutrient use efficiency and grain yield of spring wheat

    Författare :Hui Liu; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Nutrient-efficient and high-yielding spring wheat is needed in high-latitude regions. The aims of this thesis were: (1) to evaluate the effects of soil compaction and differential weather conditions on plant growth and grain yield, (2) to identify critical nutrient elements limiting plant growth and grain yield, and (3) to identify root and shoot traits at an early growth stage (early vigor) influencing nutrient use efficiency and grain yield of spring wheat. LÄS MER

  7. 5. On-farm agrohydrological analysis of the Sahelian yield crisis : rainfall partitioning, soil nutrients and water use efficiency of pearl millet

    Författare :Johan Rockström; Jim Wallace; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Natural Resources Management; naturresurshushållning;

    Sammanfattning : Sub-Saharan Africa is presently experiencing a steadily aggravated food security crisis. This crisis is a result of a rapidly growing population combined with insignificant yield increases of the major cereal crops maize, millet and sorghum, during the last decades. LÄS MER