


Volume 72, Nº 1 (2017)
- Ano: 2017
- Artigos: 7
- URL: https://journals.rcsi.science/0147-6874/issue/view/10678
Genesis and Geography of Soils
Analysis of structure and composition of soil cover in the Salym-Irtysh interfluve based on updated medium-scale soil map
Resumo
Specific features of the structure and composition of the soil cover in the Salym-Irtysh interfluve, Western Siberian Lowland, are studied with consideration of the capabilities of digital mapping. The properties of predominating and accompanying soils, which determine the modern status of boreal landscapes, are evaluated. Aspects of genesis and the Quaternary history of the investigated region are analyzed by a comparative approach. Possible trends of soil-plant cover transformation under climate changes are discussed.



Methodical aspects of investigation of dynamic of litter fall input under conditions of stationary soil lysimeters
Resumo
Time regularities of litter fall input are revealed in the investigation of phytocenoses under conditions of stationary soil lysimeters. These regularities correlate well with the dynamics typical of phytocenoses of the Botanical Garden of Moscow State University. The data on litter fall input obtained by sampling with the use of stationary litter fall traps and by the approach of collection of the total year litter fall are highly comparable. The total amount of organic substance and ash elements received with litter fall corresponds to the data given for natural ecosystems. It may be concluded that the functioning of modern phytocenoses under conditions of very restricted volume and area of soil lysimeters is normal.



Colorimetric analysis of soils using digital cameras
Resumo
Color is an important physical property in the diagnosis of soils and the description of soil profiles. Quantitative data from spectrophotometers and colorimeters have been used in soil studies for this purpose, but Munsell color description remains the main method of soil color evaluation. Low cost digital devices (cameras) could largely replace the semi-quantitative assessment of color yielded by Munsell charts, so long as they can be colorimetrically characterised to yield accurate and reproducible data. In this study, we explore the feasibility of using a digital camera to derive colorimetrically accurate images and data of 136 soil samples, using soil chart for calibration. Accurate color characterization can be achieved (ΔEab* color errors of <3) for 84% of studied soil samples, highlighting the merit of this rapid and low cost approach for soil color evaluation.



Soil Physics
Texture of the Bureya River bottom sediments in the area of the Lower Bureya HPP
Resumo
The texture of bottom sediments of the Bureya River and its tributaries in the region of the Lower Bureya HPP is studied by sieve analysis, laser diffractometry, optical microscopy, and X-ray fluorimetry. It is found that the texture of sediments in the studied area varies from pebble to silt. Sediments of the Bureya River tributaries mainly consist of fine earth (particle diameter <2 mm). Fine earth in the Bureya River is more transformed, sorted, and represented by significantly smaller particles than in the tributaries. In contrast to bottom sediments, suspension sediments are similar in particle size. The studies reveal that the bottom sediment composition corresponds to the genesis of the river basin rocks, although differences in the bulk composition of sediments are not observed on the texture level.



Changes in the pore space of soil constructions in physical laboratory models
Resumo
The dynamics of pore space structure in different filled soil constructions during water infiltration and wetting–drying processes is studied. Model laboratory experiments in columns physically simulate water infiltration after penetration at a rate of 600 mm with free outflow from the lower end of the column followed by multiple drying of soil constructions composed by alternating layers of sand, peat, and A and В horizons of soddy-podzolic soil. In two- and three-dimensional tomographic images, changes in the pore space and the interpenetration of solid phase at the boundaries between individual horizons of soil constructions are analyzed.



Ecology
Effect of introduction of clays, mineral fertilizers, and soil ameliorants on decomposition of organic pollutants in oil-polluted sand under conditions of model experiment
Resumo
The results of a model laboratory experiment in which the acidic oil-polluted sand was incubated for three months in the presence of palygorskite or bentonite clays supplemented with mineral fertilizers and lime under conditions of periodic wetting and drying are presented. A reliable decrease in the total content of nonpolar and weakly polar CCl4 extractable organic compounds and of the weakly polar compounds was established. The content of the nonpolar fraction, the amount of C14–C36 alkanes in its composition, and the (C17 + C18)/(Ci–15 + Ci–16) ratio, which was indicative of microbiological destruction of hydrocarbons, decreased significantly in the experiment with the palygorskite clay.



Agroecological evaluation of soils as a basis for controlling soil-ecological risks (by example of soils of the dry steppe zone in the Volgograd region)
Resumo
This article characterizes the soil-ecological conditions of the Romashkovskii breeding farm area in Pallasovskii district, Volgograd oblast, which is located in the dry steppe zone. An agroecological assessment is given for the farm’s soils using the Karmanov’s method of calculating soil-ecological indices and taking into account the specificity of agricultural crops. The possibility of using this evaluation as a basis for controlling soil-ecological risks in cropping is considered.


