Szerző szerinti böngészés "Jakab, Gergely"

Megjelenítve 1 - 3 (Összesen 3)
  • Nincs kép
    TételSzabadon hozzáférhető
    Insight into the dynamics of protected and non-protected carbon pools in four soils with different land uses
    Filep, Tibor; Zacháry, Dóra; Kovács, Andrea Balláné; Király, Csilla; Béni, Áron; Jakab, Gergely; Juhász, Evelin Kármen; Szalai, Zoltán; Balláné Kovács Andrea (1967-) (okleveles vegyész); Béni Áron (1978-) (vegyész); Juhász Evelin Kármen (1992-) (okleves környezetgazdálkodási agrármérnök; élelmiszerbiztonsági és -minőségi mérnök); Agrokémiai és Talajtani Intézet -- 1136; MÉK; Debreceni Egyetem
    Background and aims To provide insight into the patterns of soil organic matter decomposition, changes in the quantity of biopolymers and the correlation between them were followed using 2D correlation spectroscopy (2DCOS) FTIR. Methods Soil organic matter fractions with different vegetation/land use (grass, spruce, oak and arable) were examined in a 1-year laboratory incubation. The non-protected organic matter fraction was calculated in terms of particulate organic matter (POM), the carbon stabilized in aggregates as S + A (sand + aggregates), and the mineral-associated organic matter (MAOM) as the s + c (silt and clay) fraction. Results Forest soils (spruce, oak) exhibited high C and N accumulation in the POM fraction (48, 43% and 29, 22% for spruce and oak, respectively) due to the limited decomposition, caused by low pH and high soil C/N ratio. The 2DCOS analysis evealed that carbohydrate-protein and carbohydrate-lignin correlations could be observed most frequently during incubation. The carbohydrate-protein correlation was negative in all cases, for all fractions and for all vegetation types, which suggests biogeochemical linkage between these biopolymers. The temporal order of the spectral changes was widely varied for the vegetation types and especially for the SOM fractions. Lipid/ Lignin → Carbohydrate or Lipid → Lignin/Carboxyl/ Protein sequences were found for the protected carbon pools (S + A and s + c), possibly because of the readily available abundant N compounds present in MAOM. Conclusion Although lipids and lignin are considered as chemically stable materials that commonly remain constant during decomposition, these compounds were found to be very susceptible in all the fractions.
  • Nincs kép
    TételSzabadon hozzáférhető
    Spatial analysis of changes and anomalies of intense rainfalls in Hungary
    (2019) Jakab, Gergely; Bíró, Tibor; Kovács, Zoltán; Papp, Ádám; Sarawut, Ninsawat; Szalai, Zoltán; Madarász, Balázs; Szabó, Szilárd
  • Nincs kép
    TételKorlátozottan hozzáférhető
    The effect of soil physicochemical characteristics on zinc analysis methods
    Vona, Viktória; Tóth, Endre Andor; Centeri, Csaba; Giczi, Zsolt; Biró, Zsolt; Jakab, Gergely; Milics, Gábor; Kulmány, István Mihály; Kalocsai, Renátó; Kovács, Attila József; PhD hallgató; egyetemi oktató, kutató
    Zn is an essential micronutrient involved in a wide variety of physiological processes. Soils are tested for zinc in many countries with several extractants. Each country has its validated methods, best-suited for its soils. The current study was designed to compare different zinc content measuring methods with seventy-one samples from Hungary. The data were first compared for the whole dataset and then in certain categories such as CaCO3-content, pH, texture and clay content. The zinc content was determined by the water extraction, KCl-EDTA (ethylenediaminetetraacetic acid), Mehlich 3, CoHex (cobalt hexamine trichloride), and XRF (X-ray fluorescence) methods. Based on the analyses of all the data, we can conclude that all the methods are different. However, further analyses during the comparison of the methods based on the influencing factors, such as the pH, lime content, texture class, and clay content proved that, in some of the cases, there are similarities among the methods and, this way, we can get more knowledge on the measurements and the results provided. Farmers can gain extra knowledge from the comparison of the influencing factors to know where intervention is needed to use extra Zn for the proper fertilisation of their plants.