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Elemental composition of surface soils in Nature Park Shumen Plateau and Shumen City, Bulgaria

Abstract

Anthropogenic activities cause environmental pollution and alter biogeochemical cycles. Soils in cities and their vicinity are exposed to different pollutants. Nature Park Shumen Plateau is a protected area situated in the proximity of Shumen (Bulgaria). The aim of this research was to compare elemental composition of surface soil samples from Nature Park with two areas in Shumen city.

Soil samples from seven sites on the territory of Nature Park and from two urban sites were collected. The elemental composition of the samples was determined using Energy Dispersive X-Ray Fluorescence technique. Principal component analysis and cluster analysis were performed to interpret the complex data.

The content of 24 elements was determined: Br, Y, Zr, Mo, Ag, Cd, Sn, Sb, I, Cs, Ba, La, Ce Si, K, Ca, Ti, Mn, Fe, Cu, Zn, Rb, Sr, and Pb. Results presented here and previously showed that concentrations of heavy metals Cu, Zn, Cd and Pb are below the upper limit according to Bulgarian legislation. Concentrations of Mn and Fe in samples from Nature Park were comparable to the literature data reported for unpolluted areas. Principal component analysis and cluster analysis show similarity of the content of 24 elements between samples from Nature Park and from Shumen city. These findings are in accordance with our previous positive results from Allium-test: cytogenetic endpoints showed a presence of harmful compounds in Nature Park soils.

The content of heavy metals in the surface soils studied show a lack of environmental risk for Nature Park. However, a similar distribution pattern of the investigated elements in the park and two anthropologically influenced areas in Shumen city indicated a potential hazard in Nature Park.

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Predicting Unit Pressure Indispendable for Generation of Specific Compaction of a Soil Sample

Abstract

The objective of the research was to construct an empirical model for prediction of a unit pressure indispensable for generation of a specific compaction of soil samples. Soil material in the form of loose mass was collected from the soil layer deposited in the depth from 35 to 40 cm and then its typical properties were determined (textural group, density of solid particles, humus content, reaction, plastic and liquid limits) and in order to compact it in Proctor apparatus and in the uniaxial compression test. Results of both tests were used for construction of regression models reflecting the course of the unit strength (Pρd) necessary to generate compaction (ρdj) equal to the dry bulk density obtained in Proctor apparatus (ρdp), in relation to the sample moisture (ρdm). Searching for relations was restricted to the scope of moisure between an optimal one acc. to Proctor and the soil plastic limit. It was stated that the pressure value dp made on the soil sample in the uniaxial compression test depends significantly on w s and ρdm, and for description of this relation the use of multiple regression is sufficient. It was found out that for model samples with a textural group of silt loam and loam, differences in dry bulk density obtained in Proctor apparatus are approximately up to 0.15 g⋅cm−3.

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The influence of Chemical Works “Police” on chemical composition of Pinus sylvestris needles, Pleurozium schreberi and soil samples

Abstract

The aim of this study was an evaluation of the influence of Chemical Works “Police” (“Grupa Azoty”) on total S, N, C, Mg, K, Ca, Na Hg, Pb, Cd, Cu, Co, Cr, Mn, Ni and Zn concentrations in II-year-old needles of Pinus sylvestris L., Pleurozium schreberi (Brid.) Mitt. and soil samples. The research material was collected in spring 2013 in the coniferous habitats. The total Hg content was determined by Mercury Analyzer AMA 254. The total content of S, N and C was analysed by COSTECH CHNS elementary analyser. The total content of other elements was determined using atomic absorption spectrometer ASA iCE 3000. The highest mercury content was similar in pine needles (0.06 mg • kg-1 d. w.) and in moss (0.07 mg • kg-1 d. w.). The soil samples pH value was typical for rusty soils, in which the obtained pH-KCl value was 3.13-4.39 and pH-H2O was 3.69-5.14 (extreme acid soils). The Zn, Pb, Ni, Hg, Fe, Cu and Cr concentrations were higher in moss than in needles. The content of Pb in Pleurozium schreberi (3.13 mg • kg-1 d. w.) was few times higher than in Pinus sylvestris needles (0.073- 0.817 mg • kg-1 d. w.). The soil contamination with heavy metals was not observed. There has been almost a double reduction of sulphur content in pine needles and moss over last 20 years.

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The Effect of Edaphic Factors on the Similarity of Parasitic Nematodes in the Soil Sampled in Nurseries of Ornamental Trees and Shrubs

Abstract

The largest faunistic similarity of nematodes was found in soils sampled in coniferous nurseries where arborvitae (Thuja occidentalis - Cupressaceae), spruces (Picea spp. - Pinaceae) and pines (Pinus spp. - Pi-naceae) were grown. In soil sampled from deciduous tree and shrub nurseries, similar species composition of parasitic nematodes was found in stands of oaks (Quercus spp. - Fagaceae), black locusts (Robiniapseudo-acacia - Fabaceae) and maples (Acer spp. - Sapindaceae). In soils, especially the light and medium, from stands of coniferous and deciduous trees and shrubs, Aphelenchus avenae was often isolated. Bitylenchus dubius occurred in both types of nurseries, particularly in light soils. The largest faunistic similarities between nematodes isolated from places of growth of coniferous and deciduous plants were recorded in soils of loamy sand and sandy loam. The most abundant nematode species and the greatest similarity in species of plant parasitic nematodes were observed in soils with neutral pH or slightly acidic. Aphelenchus avenae was found in soil samples collected from both coniferous and deciduous plants, with no relation to soil acidity.

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Prediction of soil properties with machine learning models based on the spectral response of soil samples in the near infrared range

Abstract

One of the basic methods for soil analysis time and cost reduction is using soil sample spectral response in laboratory conditions. The problem with this method lies in determining the relationship between the shape of the soil spectral response and soil physical or chemical properties. The LUCAS soil database collected by the EU’s ESDAC research centre is good material to analyse the relationship between the soil properties and the near infrared (NIR) spectral response. The modelling described in the paper is based on these data. The analysis of the impact of soil properties configuration on absorbance levels in various NIR spectrum ranges was conducted using the stepwise regression models with the properties, properties squared and products of properties being explanatory variables. The analysis of partial correlation of soil properties values with absorbance values and absorbance derivative in the entire spectral range was conducted in order to evaluate the impact of the absorbance transformation (the first derivative of absorbance vector) on the change of significance of relationship with properties values. The Multi Layer Perceptron (MLP) models were used to estimate the absorbance relationship with single soil features. Soil property modelling based on the selection and transformation algorithm of raw values and first and second absorbance derivatives was also conducted along with the suitability evaluation of such models in building digital soil maps. The absorbance is affected by a limited number of tested soil features like pH, texture, content of carbonates, SOC, N, and CEC; P and K contents have, in case of this research, a negligible impact. The NIR methodology can be suitable in conditions of limited soil variation and particularly in development of thematic soil maps.

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Impact of Friction on the Uniaxial Soil Sample Compression Process

Abstract

The objective of the research was to determine the impact of the friction force between the cylinder wall and soil on the soil compaction resistance in relation to the sample height and diameter of the compaction plate. Samples with the diameter of (D) 100 mm and heights (H) of 30, 50 or 100 mm made of of soil material collected from subsoil of the selected plastic soils were used. The soil material wasidentified by the following properties: the granulation type, density of the solid phase, humus and calcium carbonate content, reaction, plastic and liquid limit. Properties of the samples were described with moisture, dry density of solid particles, porosity of aeration, plastic degree and saturation. The samples were loaded with plates of varied diameters (d A: 20; 30; 50; 70; 80; 90 and 98 mm) measuring at the same time forces on the main plate (F A) and the bottom one (F B) with the fixed diameter (d B=98 mm). The registered relationships between the forces F A and F B and plate sinkage (samples deformation) were used for determination of the impact of external friction forces (between the cylinder wall and soil) on the compression resistance of soils. It was found out that the participation of the friction force in relation to the height of samples and plate diameter varied from 0 to ca. 70%. It was proved that one may avoid the impact of the plate diameter d A on the measurement of force F A, when the relation d A /D, for samples with the heights of H30 and H50, is respectively within 0.5 ≤ d A /D < 0.8 and 0.5 ≤ d A /D < 0.7.

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Comments on the occurrence of Leptonchus granulosus Cobb, 1920 in the Slovak Republic

[1] Andrássy, I. (1958): Szabadonélö fonálférgek (Nematoda libera), Fauna Hungariae 36, Budapest [2] Bohra, P., Baqri, G.H. (2006): Plant and Soil Nematodes from Ranthambhore National Park, Rajkasthan, India. Zoos Print J., 21: 21–26 [3] Brown, D. J. F., Boag, B. (1988): An examination of methods used to extract virus-vector nematodes (Nematoda: Longidoridae and Trichodorida) from soil samples. Nematol. medit., 16: 93–99 [4] Goseco, C. G., Ferris, V. R

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Influence of organic manure amendments on water repellency, water entry value, and water retention of soil samples from a tropical Ultisol

Abstract

Lowered stability of soil aggregates governed by insufficient organic matter levels has become a major concern in Sri Lanka. Although the use of organic manure with water repellent properties lowers the wetting rates and improves the stability of soil aggregates, its effects on soil hydrophysical properties are still not characterized. Therefore, the objective of this study was to examine the relation of water repellency induced by organic manure amendments to the water entry value and water retention of a Sri Lankan Ultisol. The soil was mixed with ground powders of cattle manure (CM), goat manure (GM), Gliricidia maculata (GL) and hydrophobic Casuarina equisetifolia (CE) leaves to obtain samples ranging from non-repellent to extremely water repellent, in two series. Series I was prepared by mixing GL and CE with soil (5, 10, 25, 50%). Series II consisted of 5% CM, GM, and GL, with (set A) and without (set B) intermixed 2% CE. Water repellency, water entry value, and water retention of samples were determined in the laboratory. Soil-water contact angle increased with increasing organic matter content in all the samples showing positive linear correlations. Although the samples amended with CE showed high soil-water contact angles in series I, set A (without 2% CE) and set B (with 2% CE) in series II did not show a noticeable difference, where >80% of the samples had soil-water contact angles <90°. Water entry value (R2 = 0.83–0.92) and the water retention at 150 cm suction (R2 = 0.69–0.8) of all the samples increased with increasing soil-water contact angles showing moderate to strong positive linear correlations. However, set A (without 2% CE) and set B (with 2% CE) in series II did not differ noticeably. Water entry value of about 60% the samples was <2.5 cm. Mixing of a small amount (2%) of hydrophobic organic matter with commonly used organic manures slightly increased the water repellency of sample soils, however not up to detrimental levels. It did not generate adverse effects on water entry and increased the water retention. It was clear that intermixing of small quantities of hydrophobic organic manure with organic manures commonly used in Sri Lankan agriculture, would not generate unfavorable impacts on soils.

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Assessment of industrial contamination of agricultural soil adjacent to Sadat City, Egypt

Standardization and Equidosimetry for Radioecology and Environmental Ecology. Kiev, Ukraine, 14-20 April 2002. DOI: 10.1007/1-4020-3650-7. [5] Agency for Toxic Substances and Disease Registry (ATSDR) Toxicological Profile for Uranium: Update. U.S. Public Health Service. 1999. DOI: 10.4135/9781412963855.n24. [6] IAEA-TECDOC-1415, Soil Sampling for Environmental Contaminants, 1-12, 2004. http://www-pub.iaea.org/MTCD/publications/PDF/te_1415_web.pdf . [7] Frontasyeva M. Scientific reviews: Radioanalytical investigations at the IBR-2 Reactor in Dubna. Neutron

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The genus Longidorus (Nematoda: Longidoridae) from Bohemia and South Moravia in the rhizosphere of fruit orchards and vineyards

–41 [4] Bartošová, R., Háněl, L. (1994): Seasonal dynamics of soil nematode community in an oak-hornbeam wood. Acta Soc. Zool. Bohem., 58: 127–134 [5] Brown, D. J. F., Boag, B. (1988): An examination of methods used to extract virus-vector nematodes (Nematoda: Longidoridae and Trichodoridae) from soil samples. Nematol. Medit., 16: 93–99 [6] Chen, Q. W., Hooper, D. J., Loof, P.A.A., Xu, J. (1997): A revised polytomous key for the identification of species of the genus Longidorus Micoletzky, 1922 (Nematoda

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