WEED INFESTATION IN DIFFERENT FARMING SYSTEMS

Predmetom práce bolo sledovať vplyv ekologickej a konvenčnej sústavy hospodárenia na vývoj potenciálnej a aktuálnej zaburinenosti porastov pšenice letnej, f. ozimnej na vybraných poľnohospodárskych podnikoch Sebechleby, Plavé Vozokany a Dačov Lom. Preukazný rozdiel medzi sústavami bol zistený iba v poľnohospodárskom podniku Sebechleby, kde bola vyššia potenciálna zaburinenosť v ekologickej sústave. V ekologickej sústave v Plavých Vozokanoch a v Dačovom Lome bol zistený vyšší počet druhov burín v pôdnej zásobe semien. Dominantnými druhmi v oboch sústavách boli Chenopodium album L. a Amaranthus retroflexus L.. Vyššia aktuálna zaburinenosť bola zaznamenaná v ekologickej sústave hospodárenia. Charakteristikou oboch sústav bol výskyt trváceho druhu Cirsium arvense a nezaznamenanie druhu Amaranthus retroflexus L., ktorý mal však veľmi vysokú zásobu semien v pôde.The aim of this work was to investigate the influence of ecological and conventional farming systems on weed seedbank and actual weed infestation of winter wheat at agricultural farms Sebechleby, Plavé Vozokany and Dačov Lom. Significant differences between systems were determined only at the co-operative Sebechleby where the higher weed seedbank was in ecological system. Higher number of determined weed species in weed seedstock was in ecological system at Plavé Vozokany and Sebechleby. Dominant weed species in both systems were Chenopodium album L. and Amaranthus retroflexus L.. Higher degree of actual weed infestation was determined in ecological system. Characteristics of systems was the occurrence of perennial species Cirsium arvense and non detection of Amaranthus retroflexus L., weed that had very high weed seedbank in soil

Characterization of ODS Steels after Gamma Irradiation for Application in ALLEGRO Reactor

Oxide-dispersion strengthened steels characterization using various spectroscopic techniques is presented. Microstructure of 15% chromium oxide-dispersion strengthened steels was studied in term of vacancy defects presence and their accumulation after defined irradiation treatment, respectively. Studied materials originated from Kyoto University and studied via IAEA collaborative project focused on generation IV reactors (ALLEGRO). Samples were characterized "as received" by positron annihilation lifetime spectroscopy, the Mössbauer spectroscopy and their microstructure was examined by transmission electron microscopy as well. Samples were afterwards irradiated in Washington State University Nuclear Radiation Center via a strong gamma source (6 TBq). Damage induced by gamma irradiation was evaluated by positron lifetime measurements in emphasis on defect accumulation in the materials. We have demonstrated strong defect production induced by gamma irradiation which results from positron measurement data

Vickers Hardness and Positron Annihilation Study of Eurofer97 and ODS Eurofer

This paper describes investigations of Eurofer97 and oxide dispersion strengthened version of this steel, in as received state and after annealing. Vickers hardness test was performed on the as received specimens and after annealing at various temperatures to obtain information about development of the strength of studied materials. After identifying the temperature region where significant changes of the strength take place we applied positron annihilation spectroscopy to probe the microstructural changes in ferritic/martensitic steels. An observation of phase transformation was observed in both steels at various temperatures indicating different behaviour of the base material and its strengthened version. All applied methods proved the importance of strengthening by oxides to improve properties of steels

German and Russian Irradiated Reactor Pressure Vessel Steels from PAS Point of View

This paper presents a comparison of commercially used German and Russian reactor pressure vessel steels from the positron annihilation spectroscopy point of view, having in mind knowledge obtained also from other techniques from the last decades. The second generation of Russian reactor pressure vessel steels seems to be fully comparable with German steels and their quality allows prolongation of NPP operating lifetime over projected 40 years. The embrittlement of CrMoV steels is very low due to the dynamic recovery of radiation-induced defects at reactor operating temperatures. Positron annihilation spectroscopy techniques can be effectively applied for evaluation of microstructural changes caused by extreme external loads by proton implantation, with aim to simulate irradiation and for the evaluation of the effectiveness of post-irradiation thermal treatments. We used our actual and previous results, collected during last 20 years from measurements of different reactor pressure vessel steels in "as received", irradiated and post-irradiation annealed state and compare them with the aim to contribute to general knowledge based on experimental positron annihilation spectroscopy data

The Possibility of Consensus Regarding Climate Change Adaptation Policies in Agriculture and Forestry among Stakeholder Groups in the Czech Republic

As ongoing research efforts contribute to elucidating the consequences of climate change as well as adaptation and mitigation options, aligning the current research knowledge with stakeholder opinions and perceptions remains critical for adopting effective climate change policies. This paper utilizes an interactive survey to (1) address the aforementioned gap in studies involving three groups of stakeholders and opinion makers and (2) perform a comparative primary study of the climate change assumptions, risk perceptions, policy preferences, observations, and knowledge of Czech farmers, governmental policy-makers and researchers. This study shows that the stakeholder groups agree that the climate is clearly changing, attribute this change mostly to man-made causes and expect the negative effects to either prevail or be unevenly geographically distributed. The large majority of all three groups consider unmitigated climate change a major threat even by 2050 and agree that preparing in advance is the best sectoral strategy. Importantly, while investment in adaptation measures is considered the most efficient tool for accelerating the implementation of adaptation measures, the CAP and EU rules (as valid in 2016) are believed to hinder such measures. The results of this study have ramifications for the wider region of Central Europe