Sökning: "crops"

Visar resultat 26 - 30 av 266 avhandlingar innehållade ordet crops.

  1. 26. Nitrogen cycling communities associated to roots of arable crops in relation to management : plant, intercropping and soil effects

    Författare :Enid Ming Zhao; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Management of terrestrial nitrogen (N) has been identified as a key challenge in the implementation of sustainable agricultural practices. Transformations of inorganic N are mainly performed by microbial functional guilds that regulate the retention or loss of N. LÄS MER

  3. 27. Leguminous service crops in cereal production at high latitudes : provision of ecosystem services and disservices from a novel intercropping system

    Författare :Elsa Lagerquist; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Service crops, crops grown to provide services such as soil protection, weed control, or nutrient capture and provision, can reduce the need for mineral fertilisers and intensive weed control. However, high biomass production is necessary in order for these services to be provided. This can be difficult to achieve at high latitudes (e.g. LÄS MER

  4. 28. Environmental effects on pollen performance:potential consequences on gene flow

    Författare :Margaret Mollel; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plant ecology; siring ability; risk assessment; pollen germination; pollen tube growth rate; Nicotiana alata; morphological markers; Cucumis sativus; Genetically modified crops hybridisation; Växtekologi;

    Sammanfattning : This thesis illustrates the effects of environmental factors on pollen performance and its importance on gene flow. Pollen competitive ability between the wild and cultivated species of four genera belonging to Cucurbitaceae family was compared to evaluate the evolutionary potential for selection on pollen tube growth rate. LÄS MER

  5. 29. Conservation biological control of insect pests in two horticultural crops : a study of the cabbage root fly Delia radicum and the lily leaf beetle Lilioceris lilii

    Författare :Ulf Nilsson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  7. 30. Geochemistry of Trace Elements in the Bolivian Altiplano : Effects of natural processes and anthropogenic activities

    Författare :Oswaldo Eduardo Ramos Ramos; Prosun Bhattacharya; Jorge Quintanilla; Roger Thunvik; Jochen Bundshuh; Maria Eugenia Garcia Moreno; Luiz R.G. Guilherme; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arsenic; Bolivian Altiplano; Eastern Cordillera; Trace elements; Surface water and shallow groundwater; Soils and crops.; Mark- och vattenteknik; Land and Water Resources Engineering;

    Sammanfattning : The occurrence of As in groundwater in Argentina was known since 1917; however, the occurrence, distribution and mobilization of As and other trace elements (TEs) in groundwater in the Bolivian Altiplano are still quite unknown. An investigation applying a geochemical approach was conducted in the Poopó Basin and Lake Titicaca to understand processes of TEs in different systems such as water, soils, crops and sediments in mining areas. LÄS MER