Poiša, Liena

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Preferred name
Poiša, Liena
Official Name
Poiša, Liena
Alternative Name
Poisa, Liena
Liena Poisa
Poisa, L
Main Affiliation
Email
liena.poisa@rta.lv
ORCID
Scopus Author ID
55014398000
Researcher ID
HJZ-3782-2023

Research Output

Now showing 1 - 3 of 3
  • Publication
    Hemp (Cannabis sativa L.) as an Environmentally Friendly Energyplant
    (2011-03-05)
    Poiša, Liena 
    ;
    Aleksandrs Adamovics
    Hemp (Cannabis sativa L.) as an Environmentally Friendly Energyplant. Hemp is suitable as a renewable energy resource. The aim of this study was to clarify local hemp's (Cannabis sativa L.) possibilities for energy use. Arsenic (As), cadmium (Cd), lead (Pb) and titanium (Ti) presence in hemp was determined using an inductively coupled plasma optical emission spectrometer Optima 2100 DV. If there were increased N fertilizer rates, there were increased hemp ‘Pūriņi’ seeds and shive yield increases, but the oil content was reduced. Arsenic content was higher in the shives than in the stems with fibre. The ash content depends on non-organic substances which the plants absorb during the vegetation season. The lignin content depends on several factors: plant parts, and the N fertilizer rate. The unexplored factors have a great effect on the ash and lignin content. Hemp is suitable for cultivation and for bio-energy production in the agro-climatic conditions in Latvia.
  • Publication
    Content of Heavy Metals in the Reed Canarygrass (Phalaris Arundinacea L.) in the First Year of Harvest
    (2011-03-05)
    Rasma Platace
    ;
    Aleksandrs Adamovics
    ;
    Poiša, Liena 
    One of the major factors in achieving more biofuel is the amount of crop yield, but that is not synonymous with the yield quality. Plants are contaminated by heavy metals not only through the soil, but also from atmospheric pollution. The aim of this research was to establish the amount of heavy metals in the dry matter of reed canarygrass (Phalaris arundinacea L.). The Marathon variety of reed canarygrass was studied with two sowing periods and four Nfertilizer rate applications. The concentration level of arsenic (As), cadmium (Cd), lead (Pb) and titanium (Ti) in the samples of reed canarygrass were analysed with the coupled plasma optical emission spectrometer Perkin Elmer 2100 DV. The samples of reed canarygrass taken in April had a greater concentration of As, Cd, Pb, which means that the plants absorb the heavy metals also from the snow covering. The first year yield of reed canarygrass established a fundamental negative correlation between the amount of As, Cd, Pb and the ash content. The samples taken in April have a greater heavy metal contamination, than the samples taken in October. The sowing period fundamentally affected the concentration of lead in reed canarygrass samples, but the level of N-fertilizer rate application affected the amount of cadmium and arsenic.
  • Publication
    Evaluation of the Factors that Affect The Lignin Content in The Reed Canarygrass (Phalaris arundinacea L.) in Latvia
    (2011)
    Poiša, Liena 
    ;
    Aleksandrs Adamovics
    ;
    Rasma Platace
    ;
    Teirumnieka, Ērika 
    : In the production of granules from plants the cohesive substance lignin has a great importance, as it holds the granule together and does not allow it to disintegrate. The objective of this research was to evaluate the influencing factors of lignin content in reed canarygrass (Phalaris arundinacea L.) crop yield. In this research the varieties of reed canarygrass ‘Marathon’ and ‘Bamse’ were analysed for yields of first and second year. The lignin content of the samples was established by Classon's method. Arsenic (As), Cadmium (Cd), and Lead (Pb) and other chemical elements were established in the reed canarygrass samples with the spectrometer Optima 2100DV. The reed canarygrass second year crop yield was 3-4 times greater than the first year crop yield. A significantly correlation (p<0.05) was established in the first crop yield October samples between lignin and natrium (Na). Some correlation relationships are contradictory, which confirms that within the plant growth period the meteorological conditions are of great importance. Analysing the determining factors of lignin content it can be seen that they were influenced by the interaction of various factors - the sowing and growing period, the variety and the N-fertilizer rate application.