Sökning: "Irrigation"

Visar resultat 16 - 20 av 138 avhandlingar innehållade ordet Irrigation.

1. 16. Epiphytic lichen responses to nitrogen deposition

   Författare :Otilia Johansson; Kristin Palmqvist; Johan Olofsson; Annika Nordin; Lars E Ericson; Peter Crittenden; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lichens; air pollution; nitrogen deposition; phosphorus; growth; chlorophyll a; boreal forest; field experiment; irrigation; carbon based secondary compounds; Lavar; luftföroreningar; alg; svamp; kväve; fosfor; skog; Terrestrial ecology; Terrestrisk ekologi; ekologisk botanik; Ecological Botany;

   Sammanfattning : Nitrogen (N) deposition has increased globally over the last 150 years and further increase is predicted for the future. Nitrogen is an important nutrient for lichens, involved in many processes in both photobiont and mycobiont.  However, N can be a stressor, causing many lichens and lichen communities to disappear with increased deposition. LÄS MER

3. 17. The spectral reflectance of coniferous tree stands and of barley influenced by stress : an analysis of field measured spectral data

   Författare :Johan Kleman; Stockholms universitet; []
   Nyckelord :spectral reflectance; field measurement; middle infrared; crops; fertilisation; irrigation; coniferous forest; helicopter; measuring geometry;

   Sammanfattning : This thesis focuses on the spectral signatures for vegetation. Knowledge about the spectral characteristics of different vegetation types is imperative for an efficient use of existing remote sensing systems, and also to provide guidelines for sensor development. LÄS MER

4. 18. East African Hydropatriarchies : An analysis of changing waterscapes in smallholder irrigation farming

   Författare :Martina Angela Caretta; Lowe Börjeson; Margreet Zwarteveen; Stockholms universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; smallholder irrigation farming; local gender contract; landesque capital; common property regimes; dry lands; feminist epistemology; member checking; Kenya; Tanzania; Geography with Emphasis on Human Geography; geografi med kulturgeografisk inriktning;

   Sammanfattning : This thesis examines the local waterscapes of two smallholder irrigation farming systems in the dry lands of East African in a context of socio-ecological changes. It focuses on three aspects: institutional arrangements, gender relations and landscape investments. LÄS MER

5. 19. Irrigation with saline water using low-cost drip-irrigation systems in sub-Saharan Africa

   Författare :Louise Karlberg; Per-Erik Jansson; Reinder Feddes; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Water use efficiency; Radiation use efficiency; Management techniques; Modelling; Tomato; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : In the scope of future population support, agricultural productivity, in particular in sub-Saharan Africa, has to increase drastically to meet the UN’s millennium development goals of eradicating extreme poverty and hunger by 2015. Water availability in the root-zone limits crop production in large parts of the developing world. LÄS MER

7. 20. Irrigation and horticultural practices in ornamental greenhouse production : implementation of scientific knowledge into irrigation practices and methods

   Författare :Klara Löfkvist; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : Irrigation in greenhouse pot plant production is traditionally managed using a tactile perceptual method. This method, in this thesis called ‘the golden grip’, is based on the grower’s experiential knowledge where water requirement is determined by combining the estimated weight of the pot (both growing medium and plant) with factors such as plant age, developmental stage and size in combination with prevailing and future climate conditions. LÄS MER