Changes in the Composition and Dynamics of Soil Humus and Physical Properties in Dark Chestnut Soils of Trans-Volga Dry Steppes After 75 and 35 years of Irrigation Agriculture

Modern arable land in the Republic of Tyva is located on chestnut soils (69%) and chernozems (25%), but the former are characterized by low fertility. Soil fertility depends on the particle size distribution, structure, water-air regime, etc. Durind agricultural use of soils, the disturbance of the structure, especially of light particle size distribution, as well as depletion of humus and nutrient reserves can occur in them. Therefore, the aim of our work was to identify the influence of fallows on the change in the waterphysical properties of chestnut soils of the BarunKhemchiksky district of the Republic of Tyva. The chestnut soils of fallow and arable lands of the Barun-Khemchiksky district of the Republic of Tyva with the laying of two soil sections in arable and fallow fields were chosen as the object of the study. Soil samples from two horizons (arable and subsurface) were selected by the five-spot method. The water properties of these soils were subjected to the following analyzes: determining the water permeability of the soil according to the method of N. A. Kachinsky, determining the speed and height of rising water, determining the total capillary moisture capacity. As a result, it was found that the soil cover of the studied territories is represented by light loamy chestnut soils. Samples of fallow soil showed good water permeability with the amount of incoming water 80–100 mm per 1 hour. The water-lifting rate of soil arable land samples is slightly greater than the soil samples of the fallow: the soil sample of the arable layer of the arable land was completely moistened after 20 minutes, and the soil sample of the arable horizon of the fallow – only after 40 minutes. The moisture capacity of the fallow soil samples turned to be slightly higher than the arable land. An analysis of the studied samples indicates the improvement in the water-physical properties of the chestnut soils of the fallow compared with the arable field. Relatively low moisture capacity and accelerated water capacity indicate a destroyed and dispersed structure of arable land.

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Physical-chemical and water-physical properties of agricultural soils on inter-mountain hollows of Mountain Altai

Plant Biology and Horticulture: theory, innovation ◽

10.36305/2019-1-150-137-146 ◽

2019 ◽

pp. 137-146

Author(s):

O. A. Elchininova ◽

O. V. Kuznetsova ◽

A. N. Soyonova ◽

G. V. Chichinova

Keyword(s):

Organic Matter ◽

Physical Properties ◽

Solid Phase ◽

Arable Land ◽

Chestnut Soil ◽

Altai Mountains ◽

Chestnut Soils ◽

Physical Chemical ◽

Wide Range ◽

Mountain Basins

The purpose of the research is the study the basic physical,chemical and water-physical properties of soils of high and medium mountain basins of the Altai mountains under different types of agricultural use (arable land, hayfields, pasture). The main features of chestnut and light chestnut soils of high-mountain basins, dark chestnut soils and common chernozem of mid-mountain basins are established. These are a light granulometric composition with a high content of coarse soil, a sharp decrease of humus content and cation exchange capacity down the profile, slightly alkaline reaction of medium, and perfect structural state, except for the lower horizons of light chestnut soil. By density of the humus horizon, the soils of hayland and pasture belong to the soils rich in organic matter. Considerable density is noted also in the chernozem ordinary under an arable land where for many decades usual dump plowing is applied, minimum - in the dark-chestnut soil under an arable land where in recent years processing is carried out by a diskator which basic purpose - preparation of the soil for crops without preliminary plowing. The density of arable horizon on arable land correspond to typical values for a cultivated or a new-ploughed arable land. With the depth of the soil profile, this ratio increases, but it is lower than typical values for the subsurface horizons. The density of the solid phase varies slightly. In the upper organogenic horizons of the hayland and pasture, it is low due to the occurrence of organic matter. In the lower horizons, it is slightly higher and corresponds to the density of the solid phase for mineral soils. The porosity of the studied soils is in inverse proportion to density. The porosity of the upper horizons is perfect, and the horizons correspond to the cultural-arable layer. The porosity of the lower horizons is satisfactory. The hygroscopic moisture content of the soils under study varies in the wide range (0,7-9,9%). The maximum hygroscopicity in the sandy loam horizons is low (2-4%) and it is higher in loamy horizons (4-7%). The permanent wilting point ranges from 2,7 to 11,7%, and total water capacity - from 25,9 to 50,4%. Comparison of physical-chemical and water-physical properties of the studied soils of intermountain basins of the Altai Mountains with those of the same type of soils of the Altai territory and adjacent regions of Western Siberia indicates their proximity and even some advantage.

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NORMS OF CHANGE OF PHYSICAL PROPERTIES OF SOILS OF STEPPE, ARID AND SEMI-DESERT ZONES OF EUROPEAN RUSSIAN TERRITORIES

Dokuchaev Soil Bulletin ◽

10.19047/0136-1694-2011-67-3-19 ◽

2011 ◽

pp. 3-19

Author(s):

I. Kuznetsova ◽

N. Azovtseva ◽

A. Bondarev

Keyword(s):

Physical Properties ◽

Arable Land ◽

Steppe Zone ◽

Critical Values ◽

Equilibrium Density ◽

Desert Steppe ◽

Arable Soils ◽

Climatic Zones ◽

Chestnut Soils ◽

Dry Steppe

Norms of change of physical properties of arable land have been developed chernozems of steppe, chestnut soils of dry-steppe and light-chestnut soils of desert steppe zones of the European territory of Russia depending on the nature of anthropogenic impact. The limits of optimum, admissible and critical values of physical properties of these soils for growth and development of plants are established. For each zone, expert estimates of the distribution of soil areas with optimal, acceptable and critical values of the basic physical properties of soils are given. The greatest differences are observed in the density and structural composition of soils of different soil-climatic zones. In the steppe zone, soils with optimal values of arable layer density prevail among ordinary chernozems (1.0 - 1.2 g/cm3); among pre-Caucasian and southern chernozems - with values of 1.25-1.35 g/cm3. Among the chestnut soils of the dry-steppe zone the most common are the differences in the permissible values equilibrium density (1.30-1.40 g/cm3); in the desert steppe zone light chestnut soils with permissible (1.35- 1.45 g/cm3) and critical values (>1.45 g/cm3) of the equilibrium density. In the arable layer of soils of each separate zone agrophysical properties are significantly reduced by agrotechnical measures and close requirements of crops cultivated in the zone. Norms of change of physical properties can serve as a guide for assessing the current physical condition of arable soils and a basic basis for the development of regional fertility conservation and reproduction systems of the soil.

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The Photometric Properties of the Ap Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100080684 ◽

1976 ◽

Vol 32 ◽

pp. 365-377 ◽

Cited By ~ 2

Author(s):

B. Hauck

Keyword(s):

Physical Properties ◽

Ap Stars

The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical properties for the Ap stars, or of detecting new ones. My talk today is prepared in this spirit. The classification by means of photoelectric photometric systems is at the present time very well established for many systems, such as UBV, uvbyβ, Vilnius, Geneva and DDO systems. Details and methods of classification can be found in Golay (1974) or in the proceedings of the Albany Colloquium edited by Philip and Hayes (1975).

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The Infection of Cells by Bullet-Shaped Viruses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100063779 ◽

1969 ◽

Vol 27 ◽

pp. 372-373

Author(s):

Frederick A. Murphy ◽

Alyne K. Harrison ◽

Sylvia G. Whitfield

Keyword(s):

Electron Microscopy ◽

Physical Properties ◽

Host Cell ◽

Thin Section ◽

Cultured Cells ◽

Cell Infection ◽

Thin Section Electron Microscopy ◽

Section Electron ◽

Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

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Transmission electron microscopy of composite materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107125 ◽

1988 ◽

Vol 46 ◽

pp. 1012-1015

Author(s):

K.P.D. Lagerlof

Keyword(s):

Composite Materials ◽

Physical Properties ◽

Structural Defects ◽

Structural Composites ◽

Multiphase Materials ◽

Structural Reinforcement ◽

Transmission Electron ◽

Reinforced Fiber ◽

Particulate Reinforced Composites ◽

Definition Of

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.

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