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Modelování dopadů sdružených klimatických událostí na růst, vývoj a výnosové parametry polních teplomilných zelenin a řepky olejné v systému pro podporu rozhodování v oblasti transferu agrotechnologií – DSSAT
Potopová, Vera ; Muntean, N. ; Chawdhery, M. ; Trifan, T. ; Zehnálek, P. ; Soukup, J. ; Potop, I. ; Zahradníček, Pavel ; Možný, Martin
Tato kniha vás seznámí s nejnovějšími informačními technologiemi a jejich aplikacemi v zemědělství, včetně systémů pro podporu rozhodování, simulačních modelů plodin a dalších počítačových nástrojů. Měla by vám také pomoci s řešením problémů na regionální úrovni v otázkách souvisejících s rostlinnou výrobou a dalšími otázkami spojenými se zemědělstvím, řízením přírodních zdrojů a pěstitelských systémů a potravinovou bezpečností, jakožto i problémů spojených se změnou a proměnlivostí klimatu. Tato odborná kniha nabízí uživatelům odpovídající doplňkový materiál, který jim umožní neustále naplňovat požadavky měnícího se klimatu. Kniha je rozdělena na dvě části, teoretickou a praktickou. V teoretické části jsou shrnuty základní informace o simulacích produkce plodin, hospodaření s vodou a živinami, klimatických rizik a environmentální udržitelnosti. V praktické části jsou uvedeny postupy pro práci v programu DSSAT (Decision Support System for Agrotechnology Transfer).
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Integrated national-scale assessment of climate change impacts on agriculture: the case of the Czech Republic
Arbelaez Gaviria, Juliana ; Boere, E. ; Havlík, P. ; Trnka, Miroslav
In recent years, investigating climate change impacts in the agricultural sector at the national level has become a priority for adaptation decision-making. Most of these studies quantify the impacts\nof biophysical effects and often ignore the cross-sectoral interactions and economic effects on relative competitiveness, international trade, global food supply, and food prices for the Czech Republic. Ignoring future productivity changes globally under climate change scenarios can underestimate or overestimate climate change impacts at the national level. Here, we use GLOBIOM-CZE, a global economic model, as part of a climate change impact assessment framework to evaluate the impacts on the Czech agricultural sector in terms of environmental and economic indicators. By comparing with the baseline, the ensemble of scenarios suggests a decrease in crop area and production while increasing grassland, positively affecting livestock production by mid-century. Corn and barley show the most adverse response in production and area, while rapeseed increases under scenario RCP 8.5 with CO2 fertilization effect. Livestock products production is projected to increase, especially bovine meat and milk, as within RCP 8.5, no constraints are placed on growing greenhouse gas emissions.
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Short-term application of elevated temperature and drought influences the isotopic composition of winter wheat grains
Pernicová, Natálie ; Urban, Otmar ; Čáslavský, Josef ; Klem, Karel ; Trnka, Miroslav
The study aimed to determine the differences in carbon (δ13C) and nitrogen (δ15N) stable isotope ratios in grains of three winter wheat varieties grown under optimal and stress conditions. We found that the wheat variety has a significant effect on both δ13C and δ15N isotope ratios. Short-term (nine days) exposure to drought and high temperature during the heading or stem extension development phase significantly enhanced δ13C values, but only high temperature affected δ15N values. Enhanced δ15N values support the assumption that global warming causes a higher representation of the 15N isotope in plants. Moreover, significant interactive effects of temperature and water availability on the values of both isotopes were found implying that C and N metabolisms have been altered under the investigated stress conditions. We conclude that δ13C and δ15N isotope ratios of cereal grains are sensitive indicators of stress conditions, even short-term ones
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Estimation of winter wheat yield using machine learning from airborne hyperspectral data
Švik, Marian ; Pikl, Miroslav ; Janoutová, Růžena ; Veselá, Barbora ; Slezák, Lukáš ; Klem, Karel ; Homolová, Lucie
Methods based on optical remote sensing allow nowadays to assess crop conditions over larger areas. The assessment of crop conditions and potential estimation of crop yields in the early growth\nstages can help farmers to better target their management practice such as application of fertilizers. In this study we analysed airborne hyperspectral images acquired several times during the growing season over two experimental sites in the Czech Republic (Ivanovice and Lukavec). The field experiments on winter wheat included 12 levels of fertilisation (combination of organic and mineral fertilisers). Such an experiment design and the possibility of combining the data from two sites together increased the variability in our wheat yield dataset, which varied between 2.8 and 10.0 t/ha. Further, we used a machine learning method – namely gaussian process regression from the ARTMO toolbox to train two variants of models: a) combining the spectral data from both sites and from the multiple acquisition days and b) combining the spectral data from both sites for individual acquisition days.The results showed that it was feasible to predict wheat yield already at the beginning of April with R2 > 0.85. This promising result, however, requires more thorough validation and therefore we plan to include more data from other sites in the next steps.
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Effect of elevated CO2 concentration and nitrogen nutrition on mais response to short-term high temperature and drought stress
Simor, J. ; Klem, Karel
Within an experiment conducted in open top chambers in which two mais genotypes differing in stay-green trait were cultivated under elevated atmospheric CO2 concentration (EC) in comparison\nwith ambient CO2 concentration (AC), and in two contrast levels of nitrogen nutrition, the effect of acclimation to these factors on photosynthetic performance and water use efficiency, and subsequent response to short-term high temperature and drought stress was studied. Although EC improved water use efficiency, this effect did not alleviate the response to drought stress, and under some combinations of factors even led to a decrease in CO2 assimilation rate under drought stress. Differences in the stay- green trait between genotypes did not have a major effect on the response to high temperature and drought stress. Differences between genotypes were manifested mainly in the interaction with nitrogen nutrition, while in the Korynt genotype, non fertilised variants showed a lower response of CO2 assimilation rate to drought. Slight alleviating effect of higher nitrogen dose was found under EC conditions, while no nitrogen fertilisation rather increased drought resilience under AC conditions.
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Interactive effects of adaptation technology, based on no-till sowing into the mulch of cover crop residues, and nitrogen nutrition on photosynthetic performance of maize under drought stress
Opoku, Emmanuel ; Holub, Petr ; Findurová, Hana ; Veselá, Barbora ; Klem, Karel
The aim of this study was to evaluate the interactive effect of adaptation technology based on no-till sowing into cover crop mulch and nitrogen nutrition on photosynthetic performance of maize under short term drought stress induced by rain-out shelters. The experiment was established in two locations in the same climatic condition but differing in soil fertility. The negative effect of drought on CO2 assimilation rate was modulated by nitrogen nutrition. However, while nitrogen nutrition led to alleviating effect at the location with higher fertility, the opposite effect was found at the site with lower fertility. Adaptation technology had only a minor impact on photosynthetic response to drought, but it generally increased CO2 assimilation rate at the site with higher soil fertility and decreased at the site with lower soil fertility. We can conclude that adaptation technology, despite of assumptions, did not significantly change the resilience of maize to drought, and probably longer use of such technology is required to improve soil water retention and thus also balanced supply of water to plants. \nAt the same time, we did not find a negative impact of adaptation technology on photosynthesis which can be related to cooler soil during maize emergence and slower mineralization, although the use of adaptation technology seems to be more effective in soils with higher fertility.
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Variation of glomalin content in the Czech soils and the relationships to the chemical soil characteristics and climatic regions
Polách, Vojtěch ; Patra, Sneha ; Klem, Karel
Glomalin is being investigated as a substance that improves soil quality, the resistance of soil aggregates and play a role in carbon sequestration. This study is the first nationwide survey of the glomalin content in the soil. Soil samples were collected from 181 locations in the Czech Republic to describe the variability of glomalin content in the soils of the Czech Republic and its dependence on soil chemical properties and climatic area. Sodium citrate buffer was used to extract easily extractable glomalin (EEG), and the glomalin concentration was determined spectrophotometrically. The soil glomalin content correlates most with the ratio of humic and fulvic acids. Moreover, the interrelation between glomalin content and climatic regions was also observed. The content of glomalin decreases from the warmest regions to the coldest. We also compared the glomalin content among different soil types groups and found out that the lowest glomalin content was found in Entic Podzols and Gleysols. On the contrary, the highest glomalin content was found in Vertisols, Phaeozems and Luvisols.
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Dendrochronology improves understanding of the charcoal production history, increasing the tourist potential in the Drahany Highlands
Rybníček, Michal ; Bajer, A. ; Friedl, M. ; Knott, R. ; Kočár, Petr ; Kučera, A. ; Novák, J. ; Vavrčík, H. ; Kolář, Tomáš
Over the last two years, three selected forest sites from Drahany Highlands were examined for traces of human activity. The most frequent traces found, and common to all three sites, were remains of charcoal production. This paper provides an anatomical and dendrochronological analysis of the charcoals found in two charcoal pile remains from each site. The species composition of the charcoals at the southern site was dominated by oak, followed by birch and hornbeam. Fir was more common than oak, beech, poplar, birch and hornbeam at the central site. Fir and beech were found at the northern site. By using dendrochronology, 23 fir, oak and beech charcoals were dated with the oldest sample coming from a central site and dated from the period 1753–1758. Charcoals from the three other charcoal piles fell into the first half of the 19th century. Radiocarbon dating of charcoals selected gave a very wide age range (1640–1955), except for one case (1399–1435). Providing information on the age of a charcoal pile can help raise public awareness and interest in viewing the sites where charcoal burners used to be active in the forests.
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