Poiša, Liena

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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

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  • Publication
    EVALUATION OF CHEMICAL CONTENT IN DIFFERENT ENERGY CROPS
    (2018)
    Aleksandrs ADAMOVICS
    ;
    Poiša, Liena 
    For energy crops (reed canary grass and timothy grass), it is important to evaluate the sulphur and carbon content, and the harvested dry matter dependency on the fertilizer norm. Sulphur and carbon are important elements of a combustible material, and carbon is directly important as it forms the burning component. On the other hand, sulphur is an unwelcome element in combustible materials as it promotes environmental pollution. The field trials were carried out in sod calcareous soils in 2011–2013. A research was conducted to investigate the chemical content of two grasses: reed canary grass var. ‘Bamse’ (Phalaris arundinacea L.), and timothy grass ‘Jumis’ (Phleum pratense L.). Fertiliser norms (kg ha-1) applied in the research were: N0P0K0 (control), N30, N60, and N90. The harvest yield is one of the most important factors to obtain biocombustible materials; however, it does not mean that the amount of the harvest yield guarantees also a good quality of grasses. The research showed that the trial year had the most significant influence on both the sulphur yield and content in dry matter, the fertiliser norm essentially influenced the sulphur (η=30.1%) and carbon (η=6.5%) yield, but for the sulphur yield, a 6% interaction effect was established between the trial year and the nitrogen fertilizer norm.
  • 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.