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Sirvi Autor "Haberle, J." järgi

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  • Pisipilt
    Kirje
    Assessment of soil electrical conductivity using remotely sensed thermal data
    (2018) Křížová, K.; Haberle, J.; Kroulík, M.; Kumhálová, J.; Lukáš, J.
    Detection of heterogeneity (crop, soil, etc.) gained a lot of importance in the field of site - specific farming in recent years and became possible to be measured by different sensors. The therma l spectrum of electromagnetic radiation has a great potential today and experiments focused on describing a relation between canopy temperature and various vegetation characteristics are conducted. This paper was aimed to examine the relation between canop y temperature and electrical conductivity as one of staple soil characteristics. The related experiment was undertaken in Sojovice, Czech Republic, within an agricultural plot where winter wheat was grown in 2017 growing season. The examined plot was compo sed of three sub plots and 35 control points were selected within this area which the data were related to. A canopy was sensed by UAV (eBee carrying thermoMAP (FLIR TAU2) camera). Soil conductivity data were collected by terrestrial sampling using EM38 - MK 2 Ground Conductivity Meter in 1 m depth and 2 m sampling point distance. This dataset was later interpolated using the kriging method. The correlation analysis results showed a strong negative correlation between conductivity and thermal data ( - 0.82; p < 0.001 ). When comparing conductivity with NDVI representing the aboveground biomass, there was an opposite trend but also strong result (0.86; p < 0.001 ). Correlation coefficient of thermal data and NDVI comparison was - 0.86; ( p < 0.001 ). These preliminary results have a potential for further research in terms of soil characteristics studies.
  • Pisipilt
    Kirje
    The effects of irrigation on root density profiles of potato, celery, and wheat
    (2020) Svoboda, P.; Raimanová, I.; Duffková, R.; Fučík, P.; Kurešová, G.; Haberle, J.
    Irrigation rate should correspond to the effective root depth, however, crop root growth is influenced by a number of factors, and little data is available on the impact of irrigation. This contribution presents the results of several experiments in which the influence of sprinkler or drip irrigations on root density distribution of shallow, medium and deep rooted crops within the soil profile were studied. Irrigation significantly increased the root density of potato, celery, and wheat in the topsoil zone. On the contrary, at most cases there was only a slightly reduced root density in the subsoil layers. Total root length, to maximum root depth, only increased significantly with drip irrigation in potato. The root depths of these crops were not significantly modified by irrigation. The results suggest that the use of a constant value for the calculation of maximum irrigation depth in a specific crop may not correspond to the variability of root depth nor the distribution in different years or fields.