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Use of the Agrorisk.cz portal – an early warning system against the negative effects of weather on agriculture
Žalud, Zdeněk ; Svobodová, Eva ; Klem, Karel ; Hlavinka, Petr ; Semerádová, Daniela ; Zahradníček, Pavel ; Štěpánek, Petr ; Bláhová, Monika ; Kudláčková, Lucie ; Balek, Jan
The early warning system against negative weather effects offers a daily updated description of abiotic and selected biotic risks threatening field production at the cadastral level. It includes their 9-day forecast. The methodology is primarily intended for agronomists,plant doctors and agricultural managers, as well as scientists, agricultural consultants and representatives of public administration.
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Plevele polních plodin pěstovaných ve vybrané lokalitě východních Čech
Hroch, Josef
The diplom thesis deals with the characterization of the agricultural enterprise AGROSPOL Bolehost, a.s., its system of growing cereals and other crops and their weed infestation. The infestation was observed in the following crops: winter wheat, spring wheat, maize, peas, winter rape, sugar beet and white cabbage. The most numerous weeds found in the crops are Amaranthus retroflexus, Bromus sterilis, Capsella bursa‑pastoris, Echinochloa crus‑galli, Elytrigia repens, Galinsoga parviflora, Geranium pusillum, Chenopodium album, Lolium perenne, Mentha arvensis, Poa annua, Silene latifolia, Triplerospermum inodorum.
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Comparing of observed and simulated field crop production in HERMES2Go model at Hněvčeves locality
Bohuslav, Jakub ; Kersebaum, Kurt Christian ; Madaras, M. ; Hlavinka, Petr ; Trnka, Miroslav ; Žalud, Zdeněk
The main objective of this study was calibration and testing of crop growth model \nHERMES2Go under long–term field experiment in Hněvčeves locality (coordinate 50°18´N, 15°43´E, \naltitude 265 m.a.s.l.). Observed data of yields and the other parameters like a weather data, soil \nparameters, management practice, phenology phases etc. monitored in last 38 years was used for model \ncalibration. Input parameters were available for 4 different fertilizer practices: i) control, ii) manure, iii) \nmineral fertilizer and iv) manure together with mineral fertilizer on each plot. Observed data are \navailable for yields of main and by–product and above ground biomass. The main grown crops were \nsugar beet, spring barley, winter wheat, silage maize, oat and alfalfa. Outputs of the model for main \nproduct are relatively accurate, but values of by–product requires additional calibration parameters \nsettings together with above–ground biomass.
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The effect of drought and nitrogen fertilization on the production, morphometry, and spectral characteristics of winter wheat
Trunda, Petr ; Holub, Petr ; Klem, Karel
Methods of study based on the spectral reflectance of vegetation are now commonly used in researching both natural ecosystems and field crops.The aims of this experiment were to evaluate the effect of drought and nitrogen (N) fertilization on N use efficiency in winter wheat and use the obtained spectral characteristics to assess stand heterogeneity as a potential consequence of different crop nutrition. Twelve experimental plots of winter wheat were manipulated to drought from 8 May 2013 to 12 June 2013. The effect of drought was observed in two treatments: control without fertilization (N0; 0 kg N ha−1) and N fertilization (N140; 140 kg N ha–1). Plant samples were then taken for determination of above-ground biomass and N content in dry matter. Spectral characteristics of wheat were measured in the earing phase at canopy level. The effect of drought on the morphometric parameters of winter wheat was statistically significant only on N-fertilized plots (N140). Total above-ground biomass decreased by a significant 18% in the N140 treatment as a result of the simulated drought. This decrease was reflected in statistically significant reductions of all individual plant parts (stems, leaves, spikes) in N140. Responses to drought stress were observed in many vegetation indices, particularly in NDVI, GNDVI, and WI/NDVI. The results show there are significant relationships between N content in the grain and vegetation indices. A quite marked separation was observed in the relationships between dry and ambient treatments for vegetation indices NRERI, TCARI/OSAVI, VOG2 and GM. Generally, the impact of drought increased at higher levels of N content in the grain, which corresponded with the results of morphometric analysis. Use of reflectance in the study of vegetation and field crops regarding risk assessment of mineral N leaching from soils has considerable potential especially in mapping large areas and monitoring temporal changes relating to N release.
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Utilization of economical threshold in management of pest control in field crops
Kocourek, František
In the methodology, basic principles of expert system for decision about using of pesticides according to economic threshold are described. Decision about using of pesticides is based on analysis of economical parameters and evaluation of pesticide impact on the environment. Methods of construction of damage curves for pests and diseases of field crops are described. Damage curves are quantified for economically important diseases and pests of field crops and injury levels are specified for 77 diseases and pests. Model for development of multidimensional economic threshold is described. It is an original mathematical model that includes (beside formerly used parameters as cost of pest control, yield, and price of product) two new parameters, efficacy of pest control and environmental impact of active substance of pesticide. Method of determination of environmental impact of active substances of pesticides is described and its values are given for pesticides registered in the Czech Republic against pests and diseases in field crops. In the end of methodology, principles of pest management on the basis of economic thresholds are summarized.
Fulltext:  PDF
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Problems of damages caused by game to field crops
We evaluated the importance of field crops for the ungulate game species. The large herbivores exploit the field crops at the different intensity according to crop species, season, feeding strategy, human disturbance in the forest etc. The field crops are generally not too important as a food resource for wild ungulate species and in the environment with sufficiency of herb and shrub layer in the forest environment they prefer native diet components.
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The evaluation of yield losses after simulated defoliation
Cerkal, R. ; Dvořák, J. ; Kamler, Jiří ; Vejražka, K. ; Šejnohová, H.
We evaluated the importance of field crops for the ungulate game species. The large herbivores exploit the field crops at the different intensity according to crop species, season, feeding strategy, human disturbance in the forest etc. The field crops are generally not too important as a food resource for wild ungulate species and in the environment with sufficiency of herb and shrub layer in the forest environment they prefer native diet components.
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Free living ungulates and field crops
Kamler, Jiří ; Dvořák, J. ; Heroldová, Marta ; Homolka, Miloslav
We evaluated the importance of field crops for the ungulate game species. The large herbivores exploit the field crops at the different intensity according to crop species, season, feeding strategy, human disturbance in the forest etc. The field crops are generally not too important as a food resource for wild ungulate species and in the environment with sufficiency of herb and shrub layer in the forest environment they prefer native diet components.
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