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Sirvi Autor "Maliarenko, O." järgi

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  • Pisipilt
    Kirje
    Carbon and nitrogen uptake in above- and below-ground biomass of cereal crops in the integrated farming system
    (Estonian University of Life Sciences, 2023) Rancane, S.; Lazdins, A.; Zusevica, A.; Zute, S.; Jansone, I.; Damskalne, M.; Zarina, L.; Korolova, J.; Maliarenko, O.
    A significant reduction in greenhouse gas (GHG) emissions, as well as technologies that ensure removal of CO2 from the atmosphere, are necessary to achieve the set goals for the transition to carbon neutrality. During the crop growth cycle, a significant amount of biomass is produced, and carbon (C) and nitrogen (N) are captured both by the harvested crop removed from the field and by residues left on the field. The trials were conducted to find out patterns between crop and residues while trying to figure out the amount of captured C and N. In this study data of the most widely grown cereal crops in Latvia are summarized. The data are representative, obtained in different agroclimatic conditions, they vary both by species and variety, by year and fertilizers applied. The mean amount of biomass from cereal crops left on the field was 1,070.9 g m-2 DM, besides, 906.7 g m-2 of that was made up of above-ground (AG) residues and 164.2 g m-2 of below-ground (BG) residues. On average, 471.8 g m-2 C and 14.3 g m-2 N were captured, including: 411.2 g m-2 C and 12.9 g m-2 N by AG residues; 60.7 g m-2 C and 1.4 g m-2 N by BG residues. Regularities between grain yield and residues were found, however, they were not very strong. The dataset should be enlarged to reduce uncertainty. As the data calculated from crop have a greater uncertainty, the GHG inventory should be calculated according to the average AG and BG biomass, which provide more accurate data.
  • Pisipilt
    Kirje
    Measuring and alleviating drought stress in pea and lentil
    (Estonian University of Life Sciences, 2023) Prysiazhniuk, O.; Maliarenko, O.; Biliavska, L.; Voitovska, V.; Kononenko, L.; Klymovych, N.; Poltoretska, N.; Strilets, O.; Voievoda, L.
    Water deficit in the soil can cause drought stress in plants and drastically affect plant growth and crop yield. Therefore, early detection of drought stress in plants followed by the timely application of agronomic measures to alleviate plant conditions is crucial. This research aimed to study the agronomic practices that could reduce the sensitivity of pea and lentil to drought stress. The practices included (i) soil amendment with moisture retainer (hydrogel), (ii) seed treatment with a growth regulator to promote root formation, (iii) application of a biological formulation to boost soil mycorrhizal biota, and (iv) foliar application of micro fertilisers. The research was carried out in Ukraine in 2015−2020. Drought stress in plants was detected by measuring chlorophyll fluorescence with a portable fluorometer Floratest and calculating the ratio of variable to maximum fluorescence Fv/Fm of the photosystem. The content of proline, high values of which in vegetative organs point out to stress in plants, was determined by colorimetric analysis using ninhydrin. In pea, the incorporation of hydrogel (Aquasorb) and growth regulator (Mycofriend) combined with seed treatment (Kelpak SC) and foliar application of micro fertiliser (Biovit or Freya-Aqua Legumes) at BBCH 14 led to obtaining Fv/Fm values from 0.81 to 0.82. Similarly in lentil, the maximum value of Fv/Fm (0.67) was obtained with the application of all studied agronomic practices, with the correlation coefficient between yield and Fv/Fm at the flowering stage (BBCH 61) r = 0.97. In pea, the correlation between yield and Fv/Fm at the budding stage (BBCH 51) was r = 0.99. The content of proline in photosynthetic plant organs was species-specific; however, in the control treatment, where plants were exposed to drought, its maximum value was 1.10 μmol g-1 in pea and 1.40 μmol g-1 in lentil, while with the application of the proposed agronomic practices proline content was only 0.56 μmol g-1 in pea and 0.36 μmol g-1 in lentil. Obtained strong correlation between proline content in plant vegetative organs and the ratio of variable to maximum fluorescence Fv/Fm of the plant photosystem indicates that measurement of Fv/Fm with portable fluorometer might be an effective method of early identification of drought stress in pea and lentil.