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The study has determined the composition of dissolved organic matter in Luvisols, Fluvisols and Histosols using spectroscopic (FTIR) and chromatographic (HPLC and Py-GCMS) methods. It has been found that aliphatic hydrocarbons (linear) containing from 4 to 12 atoms of carbon constitute the dominant group of compounds included in the dissolved organic matter (DOC). The preparations isolated from Histosols and Luvisols demonstrated a higher proportion of hydrophobic fraction with a longer retention time probably containing more compounds with long-chain aliphatic and simple aromatic structure than the DOC of Fluvisols. The differences in infrared spectra are evident particularly in the wave number between 1650–1030 cm⁻¹. The DOC of Histosols is richer in aromatic compounds (range 1620 cm⁻¹) but the DOC of Luvisols and Fluvisols is richer in alkene chains and hydroxyl (OH) and methoxy (OCH₃) groups. The results showed differences in the composition of the DOM across the soils, caused their genesis.
The aim of the study was evaluation of the effect of dressing seed material of spring barley with a humus preparation and foliar potassium fertilization with Drakar on its yield and content of nitrogen, phosphorus, potassium and magnesium in the grain. One-way field experiment was carried out in the years 2006-2008, in Chrząstowo (53°09’ N; 17°35’ E) near Bydgoszcz, on soil classified as mesic Typic Hapludalfs, of a granulometric composition of light sandy loam. The effect of the following was evaluated: humus preparation Humistar (12% humic acids and 3% fulvic acids), used for dressing at a rate of 1 dm3 per 50 kg of barley grain (1), foliar fertilizer Drakar (25.7% K and 3% N), applied at two doses of 2 dm3·ha-1, before flowering and after its end (2), as well as the combined application of Humistar and Drakar (3). The results of using Humistar and Drakar were compared with the control (4) where these preparations were not used. A significant increase was found in 1000 grain weight and yield of barley grain under the effect of dressing the seed material with Humistar. However, this factor’s effect on spike density per unit of area or on the grain number per spike was not indicated. Foliar fertilizer Drakar did not affect significantly the grain yield or its components. The studied preparations did not affect significantly the leaf greenness index in barley in the stage of tillering, shooting and flowering. However, a positive effect of Humistar was found on values of this index in the milk stage. The total nitrogen concentration in barley grain was independent of the used preparations. However, a significant increase in the content of phosphorus and magnesium was found in barley grain dressed with Humistar. Concentration of phosphorus and potassium in barley grain on plots with a foliar fertilization with Drakar was lower, while of magnesium higher than on the control.
Considering the discrepancies in the reports on seasonal changes in the content of dissolved organic carbon, this paper concerns the research which aimed at defining the content and seasonal changes in dissolved organic matter (DOM) in arable and meadow soils in moderate climate conditions. The research has involved the soils sampled in the kujawsko-pomorskie province (Poland). Gleic Phaeozems (meadow soils), Brunic Arenosols and Eutric Cambisols were sampled from the depth of 0-30 cm, 30-60 cm and 60-100 cm, November 2011 through September 2013. The soil samples were analyzed for dry weight content, pH, content of total organic carbon and total nitrogen. DOM was extracted with 0.004 mol·dm⁻³ CaCl₂, in the extracts the content of dissolved organic carbon (DOC) and dissolved nitrogen (DNt) were assayed. The share of DOC was determined by the soil management. The analysis of variance did not show significant differences in the content of TOC and Nt across the soil sampling dates. Were recorded changes in DOC and DNt between successive sampling dates; for topsoil for DOC – from -12.06% to 13.34% (meadow soils) and for DNt -40.84% to 47.44% (arable soils).
The aim of the paper was to determine the effect of soil pollution with polycyclic aromatic hydrocarbons (PAHs) on the content of carbon, nitrogen and the share and content of dissolved organic carbon (DOC) and dissolved nitrogen (DNt). The study was carried out based on soil samples (Luvisols, Phaeozems, Haplic Arenosols, Fluvisols) representative of the Kujawsko-Pomorskie Region.Soil samples were polluted with selected PAHs (fluorene, anthracene, pyrene and chrysene), in the amount corresponding to 10 mg PAHs kg⁻¹. The PAHs-polluted soil samples were incubated for 120, 180 and 360 days at the temperature of 20-25°C and fixed moisture (50% of field water capacity). In the soil samples prior to and after incubation the following were determined: the content of total organic carbon (TOC), and total nitrogen (Nt), as well as the content and share of DOC and DNt. It was shown that soil pollution with PAHs (anthracene, fluorene, pyrene, chrysene), in general, did not result in significant changes in the content of TOC and Nt. The content and share of dissolved organic carbon and nitrogen is characteristic for a given soil. The pollution of soils with PAHs disturbs the balance, resulting in temporary changes in the content and share of soluble organic matter throughout the incubation of the soil material polluted once with selected PAHs.
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