Szerző szerinti böngészés "Filep, Tibor"

Megjelenítve 1 - 5 (Összesen 5)
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    A szervetlen-C és a szerves-C mennyiségének változása egy homoktalajban, meszezés hatására
    (2002) Nagy, Péter Tamás; Filep, Tibor; Kincses, Sándorné
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    Az NPK-trágyázás hatása a kukorica tápelemfelvételének dinamikájára, öntözött és nem öntözött viszonyok között
    (2002-03-27) Kincses, Sándorné; Filep, Tibor; Loch, Jakab
    The effect of NPK-fertilization on the dynamics of nutrient uptake of maize (Zea mays L., cv. Clarica) was examined on chernozem soil under irrigated and non-irrigated conditions in a field experiment. The following results were made: • the element concentrations in the plant decreased over time, • there is no difference between the dynamics of nutrients on irrigated and non-irrigated sites because rainfall was satisfactory for plants in vegetation period, • the N doses not only significantly increase the nitrogen content in maize, but also have a noticable effect on Ca and Mg concentrations, • because of the acidifying effect of N-fertilizers, increasing the amount of N-fertilizer increased the Mn, Zn, Cu content of the plants, • the P doses have a significant effect on the maize P and N content and the Zn concentration of the plant via P-Zn antagonism in the soil, • as the high K doses treatments alter the ion ratios in the soil, the Ca, Mg content of the plant decreased.
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    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.
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    A szervetlen-C és a szerves-C mennyiségének változása egy homoktalajban, meszezés hatására
    (2002-03-27) Nagy, Péter Tamás; Filep, Tibor; Kincses, Sándorné
    The effect of liming on different organic and inorganic carbon forms in soil was studied in a pot experiment on acidic sandy soil (pH(H2O)=4.38; pH(KCl)=3.42). We used three kinds of liming doses (which were signed M1, M2, M3,). M1 was half of the M2 dose; M2 was the calculated lime dose and M3 was one and the half dose of M2. Lime (CaCO3) was mixed into the soil in powdery form. In addition to liming treatments, a uniform N, P and K treatment (1-1-1g N, P2O5 and K2O per pot) was given. Water supply was set up to 75% field water capacity of soil. Pots were watered daily. During the vegetation period soil and plant (oats; Avena sativa L.) samples were taken from each treatment three times (after 6-10-15 weeks). We determined inorganic- and total-C of the soil by Vario EL element analyser (based on dry combustion method) and calculated the organic-C. The conclusions can be summarized as follows: – Liming treatments had a significant positive effect on the soil-pH and caused quantitative change of different carbon forms of soil. – Increasing tendency of liming doses caused more intensive changes in inorganic- and organic-C forms of soil. – A significant correlations was found between the soil pH and the inorganic-C fraction of soil. – A decreasing correlation was found between the vegetation period and the organic-C fraction.