3 research outputs found
Zawarto艣膰 zwi膮zk贸w fenolowych w glebach pochodz膮cych z dw贸ch trwa艂ych do艣wiadcze艅 nawozowych
The objective of the study was to compare the impact of three systems of multiannual fertilization applied in two long-term field experiments on the content of phenolic compounds in the soil. In the study, both natural (manure, slurry) and mineral (NPK) fertilizers were used, along with combined, organic-and-mineral fertilization. Experiment I was established in 1972 on grey brown podzolic soil; experiment II, in 1973 on brown soil. In both experiments crops were cultivated in a 7-year rotation, with a 75% share of cereals. The experimental samples were taken from the top layer of soil after 36 (experiment I) and 35 (experiment II) years following the establishment of the experiments. It was demonstrated that the presence of phenolic compounds in the soils was significantly dependent on the contents of organic C and total N, type of soil and the type and dose of used fertilizers. In grey brown podzolic soil, the content of total phenolic compounds was at a lower level than the content found in brown soil. Multiannual fertilization contributed to an increase in the content of total phenolic compounds in relation to the values obtained in control objects, which was particularly reflected in the soil originating from objects fertilized with slurry applied at a dose being equivalent to manure in terms of the amount of introduced organic carbon. The percentage of water-soluble phenols in the total content of these compounds in grey brown podzolic soil was at the level of 18.4%, while in brown soil it amounted to 29.1%.Zwi膮zki fenolowe to grupa substancji biologicznie aktywnych, pochodz膮ca najcz臋艣ciej z naturalnych
przemian substancji organicznej b膮d藕 z biosyntezy prowadzonej przez mikroorganizmy. Istota dzia艂ania
tych zwi膮zk贸w w glebie polega na zaburzaniu przemian metabolicznych w ro艣linie, co powoduje zahamowanie
ich wzrostu i obni偶enie plonowania. Celem pracy by艂o por贸wnanie wp艂ywu trzech system贸w wieloletniego
nawo偶enia stosowanego w dw贸ch trwa艂ych do艣wiadczeniach polowych na zawarto艣膰 zwi膮zk贸w fenolowych
w glebie. W badaniach stosowano nawozy naturalne (obornik, gnojowica), mineralne (NPK) oraz nawo偶enie
艂膮czne organiczno-mineralne. Do艣wiadczenie I za艂o偶ono w 1972 r. na glebie p艂owej, natomiast do艣wiadczenie
II w 1973 r. na glebie brunatnej. W obu do艣wiadczeniach ro艣liny uprawiano w 7-letnim zmianowaniu, z 75%
udzia艂em zb贸偶. Materia艂 do bada艅 stanowi艂y pr贸bki pobrane z wierzchniej warstwy gleby po 36 (do艣wiadczenie
I) i 35 (do艣wiadczenie II) latach od chwili za艂o偶enia do艣wiadcze艅. Wykazano, 偶e obecno艣膰 zwi膮zk贸w fenolowych
w glebach by艂a istotnie uzale偶niona od zawarto艣ci C organicznego oraz N og贸艂em. Na ich zawarto艣膰 istotny wp艂yw
mia艂 rodzaj gleby oraz rodzaj i dawka stosowanych nawoz贸w. W glebie p艂owej 艣rednia zawarto艣膰 zwi膮zk贸w
fenolowych og贸艂em kszta艂towa艂a si臋 na poziomie ni偶szym w stosunku do zawarto艣ci stwierdzanych w glebie
brunatnej. Wieloletnie nawo偶enie wp艂yn臋艂o na wzrost zawarto艣ci zwi膮zk贸w fenolowych og贸艂em w stosunku do
warto艣ci uzyskanych w obiektach kontrolnych, co szczeg贸lnie uwidoczni艂o si臋 w glebie pochodz膮cej z obiekt贸w
nawo偶onych gnojowic膮, stosowan膮 w dawce r贸wnowa偶onej z obornikiem pod wzgl臋dem ilo艣ci wprowadzanego
w臋gla organicznego. Udzia艂 form fenoli rozpuszczalnych w wodzie w og贸lnej zawarto艣ci tych zwi膮zk贸w w glebie
p艂owej kszta艂towa艂 si臋 艣rednio na poziomie 18.4%, za艣 w glebie brunatnej 29.1%
The effect of L-theanine supplementation on the immune system of athletes exposed to strenuous physical exercise
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International Asteroid Warning Network Timing Campaign: 2019 XS
As part of the International Asteroid Warning Network's observational exercises, we conducted a campaign to observe near-Earth asteroid 2019 XS around its close approach to Earth on 2021 November 9. The goal of the campaign was to characterize errors in the observation times reported to the Minor Planet Center, which become an increasingly important consideration as astrometric accuracy improves and more fast-moving asteroids are observed. As part of the exercise, a total of 957 astrometric observations of 2019 XS during the encounter were reported and subsequently were analyzed to obtain the corresponding residuals. While the timing errors are typically smaller than 1 s, the reported times appear to be negatively biased, i.e., they are generally earlier than they should be. We also compared the observer-provided position uncertainty with the cross-track residuals, which are independent of timing errors. A large fraction of the estimated uncertainties appear to be optimistic, especially when <0 2. We compiled individual reports for each observer to help identify and remove the root cause of any possible timing error and improve the uncertainty quantification process. We suggest possible sources of timing errors and describe a simple procedure to derive reliable, conservative position uncertainties. 漏 2022. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]