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Spectral Indices as a Tool for Hop Growth Evaluation
Seidlová, Jana ; Procházka, Pavel ; Kumhálová, Jitka
The use of unmanned aerial vehicles (UAV) to monitor crop growth is nowadays a common non-invasive way how to obtain information on the current state of crops. Spectral indices derived from multispectral images obtained in the right growth stage can then serve as a good data source for agro-technical interventions and yield estimation. Hop belongs among the crops where it is possible to scan the individual growth parameters very exactly. In the year 2021, significant precipitation amounts were recorded during the growing season, when it turned out that UAVs are a very powerful tool for determining the quality of production or quantification of vegetation damage compared to the previous year (2020). It was found that the common spectral indices were possible to use for calculation leaf area, structure, vigor and chlorophyll content of hop gardens.
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Assessment of changes in slope topography and soil depth redistribution in relation to different soil tillage technologies
Ureš, Jan ; Kumhálová, Jitka (advisor) ; Novák, Petr (referee)
Water, wind, or tillage-induced soil erosion can significantly degrade soil quality and decrease crop yield from farm fields. Traditionally, the research in soil erosion is mostly focused on water or wind erosion. Recent studies over last two decades, however, point to the importance of tillage operations as a source of soil translocation on hilly agricultural land. Tillage disturbs the soil not only vertically but also horizontally by throwing soil in the tillage direction.
This study was designed to assess the soil translocation effect in topsoil before and after 5 tillage operations by using three different practices, namely mouldboard ploughing (A), chisel plough (B), and disc harrow (C) in the Chernozems region at the Sardice (South Moravia, the Czech Republic).
The influence of different tillage practices on the changes in depth of topsoil was assessed through description of 37 shallow pits - 10 pits was digged out before the tillage operations and then other 27 pits after five tillage operations. The results of the soil survey are based on the evaluation of the stratigraphy of the soil profile where the potential loss of topsoil was determined by a change in transition between the dark Ac horizon and yellow loess Ck horizon and by the type of the transition. Shift of topsoil after five performed operations is in the range of 9-15 cm at the top position of concave-convex slope and 4-14 cm at the top of concave slope. From the results of the experiment are also apparent significant shifts across to each tillage practice (C to A), which are, however, more or less caused by the shape of the slope.
By creating and comparing the DEM for the conducted experiment I managed to learn that the largest transport of soil particles was caused by mouldboard plough. Transport of soil particles was larger in the vertical direction than in the horizontal and moved in the range
of -5 to +13 cm. When undermining by a chisel plough was a significant horizontal shift of soil particles to the sides in the range of -5 to +5 cm. The method of shallow tillage with a disc harrow showed a change of the relief in the horizontal direction also in the range of -5 to +5 cm.
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Influence of water erosion parameters choice stand establishment in relation to the location and arrangement of the land
Faltejsková, Michaela ; Novák, Petr (advisor) ; Kumhálová, Jitka (referee)
The aim of the diploma thesis was to evaluate and assess the crop stand establishment in terms of resistance the soil to water erosion. For this purpose, a field experiment was set up in Nespeská Lhota, which consists of six different crops and methods of treatment and one control variant maintained without vegetation. Measured variables for evaluating were the surface runoff and soil washes away. There was used the rainfall simulator for measurement.
Based on the results presented in the diploma thesis a positive impact of reduced tillage on measured values of water erosion can be confirmed. The consequence is especially a reduction of erosive washes of soil and surface runoff. Also the positive effect of ground cover with organic matter was confirmed, which contributes to the better soil qualities and the soil is less prone to water erosion.
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Topographical data sources and derived topographic attributes for describing the variability of agricultural plot
Ladmanová, Markéta ; Kumhálová, Jitka (advisor) ; Komárek, Jan (referee)
This diploma thesis is focused on examination of effect topography on yield on the field. Theoretical research is given in literary overview and it is focused on sources of elevation data in conditions of the Czech Republic. Further there is given description of topographic attributes, which have influence on crop on the agricultural field.
Practical part of this thesis processed data about agricultural field in Vendolí near Svitavy in East Bohemia. One of aims of this thesis was to compare two sets of elevation data. First set of elevation data was provided by Czech office for surveying, mapping and cadastre, data came from airborne laser scanning. Second set of elevation data was measured by DGPS receiver placed on combine harvester during the harvest. Topographic attributes were derived from these two sets of elevation data with help of tools in software ArcGIS 10.2. In the further process topographic attributes were compared with yield of winter wheat from 2014 to assess relationship between topography and yield. In given data there was found dependence of yield on digital elevation model (higher amount of yield was found in higher elevations). Significant relationship between yield and other topographic attributes has not been proved.
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Comparison of selected vegetation indices and determination of suitability for yield description on agricultural field
Křížová, Kateřina ; Kumhálová, Jitka (advisor) ; Novák, Petr (referee)
Calculation of vegetation indices (VI) is an effective method how to evaluate a condition of a monitored vegetation. It is a non-destructive and low-cost approach and its results are crucial for planning agronomic management within a monitored field.
Diploma thesis deals with the determination of suitability of selected VI to describe the yield variability related to topographic attributes and weather conditions. The study area was a 11.5 ha field. To derive selected VI LANDSAT 5 images with a spatial resolution of 30 m were used. These images were taken in years 2005 and 2011 for winter wheat and in years 2006 and 2010, when oat was grown. SW ENVI and ArcGIS were used to obtain specific values. Those were used for statistical analysis. The results indicated a strong relationship between all selected VI and yield, respectively topographic factor. Selected VI derived from LANDSAT 5 images can be used to describe yield variability over a monitored field.
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