Granulometric Composition Of Soil Research Articles

Maximum soil density of Entisols as a function of silt content

ABSTRACT: Degradation that occursin agricultural soils causes compaction.Soil density (DS) analysis has been reported to be an unreliable method of measuring the extent of soil compaction, because it varies with the soil granulometric composition and organic matter (OM)content. However, soil relative density (DR) is a good indicator that facilitates the measurement of the degree of compaction and thus, soil comparison and management techniques. Quotient between the DS and its maximum density (Dsmax) gives the DR. This study aimed to assess the effect of the granulometric composition on the physical-hydrological properties of the high-silt containing soils,under no tillage. Samples from disturbed and undisturbed structures of 18 soils were collected from the state of Rio Grandedo Sul following the no-tillage system. Once the granulometric size, OM content, soil density, maximum soil density and relative density were determined,the results indicated a drop in the Dsmax value when silt and MO were added;however, the addition of clay and clay-plus-silt revealed no significant effect. When the silt and MO content increased the soil density decreased. The DR, however, was not affected by either the granulometric composition or OM content. A difference was observed between the DR calculated from the determined Dsmax and that estimated by the Dsmax assessed based on the clay levels.Silt content was reported to exert a different influence on the physical-water properties of the silt soils than the clayey ones.

The use of spectrum-zonal images by landsat 7 etm+ for diagnosing soil characteristics of Ukrainian polissya

A dependence of characteristics of the spectrum-zonal raster images by Landsat 7 ETM+ was examined, in particular, albedo of reflectivity r and certain vegetation indexes, on the soil properties in the transition zone of Central Polissya in Ukraine. In present paper we applied an algorithm for constructing agrochemical schematic maps using Quantum GIS. An importance was established of the selection of approaches to diagnosing the magnitudes of soil and agrochemical indicators of soil properties with attributes of hydromorphicity, particularly during the formation of statistical sampling to conduct a correlation-regression analysis. It is demonstrated that the possibility of identification and the quality of diagnosing certain individual indicators of soil properties, as well as informativeness of certain channels, depends on putting an accent (priority) in the form of compiling uniform statistical sample. It was found that combining a sample by the uniformity of the type of soil and granulometric composition of soils allows a more pronounced identification of dynamic magnitude of the nutrient content – movable phosphorus and exchangeable potassium. It is established that given the multi-component screening of the Earth surface with vegetation, a degree of correlation connection between characteristics of spectrum-zonal images and the indicators of soil properties beyond the vegetation period is significantly reduced.

DEFINITION OF THE CRITERIA INFLUENCING ON CULTIVATION CONDITIONS OF ONIONS

Bulb onion is one of the most profitable crops among the vegetable group; this fact determines the relevance of the choice of the most suitable plots for its growing on light kastanozems. The purpose of the research is the scientific substantiation of methodical positions and the definition of reliable criteria for the assessment of land for the cultivation of bulb onions on intensive technology. The studies were conducted in the household «Khvan V.A.» in 2008-2015 on the following onion hybrids: Banco F1, Hilton F1, Exacta F1, Gladstone F1, Rossa di Firenze F1, Manas F1. During the study of crop rotations, natural soil fertility and fertilizers system the standard for vegetable growing methods of field experiments were used. The influence of growing conditions on yield of bulb onion was analyzed. The criteria of soil estimation, allowing predicting success of the growth and development of onion plants were determined. Correlation analysis showed that the granulometric composition of soils (r=0.79), natural fertility (0.71) and the system of fertilizers (r=0.54) have most significant influence on the formation of the yield. Found that rye and wheat, grown for green manure, are the best precursors on light kastanozems. It is revealed that onion is necessary to place the on medium loamy soils, where the highest productivity of hybrids is observed. The significant influence of the granulometric composition of soil on onion plants was substantiated. The best soil differences for this culture (light loam, medium loam), where productivity of crops is increased to 80-90 t/ha were selected. Criteria that determine the success of the cultivation of bulb onion on light kastanozems were identified, which will help to efficiently plan the crop rotation and predict the crop growth to increase production stability.

Impact of temperature on the biological properties of soil

AbstractThe aim of the study was to determine the response of soil microorganisms and enzymes to the temperature of soil. The effect of the temperatures: 5, 10, 15, 20, and 25°C on the biological properties of soil was investigated under laboratory conditions. The study was performed using four different soils differing in their granulometric composition. It was found that 15°C was the optimal temperature for the development of microorganisms in soil. Typically, in the soil, the highest activity of dehydrogenases was observed at 10-15°C, catalase and acid phosphatase – at 15°C, alkaline phosphatase at 20°C, urease and β-glucosidase at 25°C. The highest colony development index for heterotrophic bacteria was recorded in soils incubated at 25°C, while for actinomycetes and fungi at 15°C. The incubation temperature of soil only slightly changed the ecophysiological variety of the investigated groups of microorganisms. Therefore, the observed climate changes might have a limited impact on the soil microbiological activity, because of the high ability of microorganisms to adopt. The response of soil microorganisms and enzymes was more dependent on the soil granulometric composition, organic carbon, and total nitrogen than on its temperature.

Modelling soil water retention using support vector machines with genetic algorithm optimisation.

This work presents point pedotransfer function (PTF) models of the soil water retention curve. The developed models allowed for estimation of the soil water content for the specified soil water potentials: –0.98, –3.10, –9.81, –31.02, –491.66, and –1554.78 kPa, based on the following soil characteristics: soil granulometric composition, total porosity, and bulk density. Support Vector Machines (SVM) methodology was used for model development. A new methodology for elaboration of retention function models is proposed. Alternative to previous attempts known from literature, the ν-SVM method was used for model development and the results were compared with the formerly used the C-SVM method. For the purpose of models' parameters search, genetic algorithms were used as an optimisation framework. A new form of the aim function used for models parameters search is proposed which allowed for development of models with better prediction capabilities. This new aim function avoids overestimation of models which is typically encountered when root mean squared error is used as an aim function. Elaborated models showed good agreement with measured soil water retention data. Achieved coefficients of determination values were in the range 0.67–0.92. Studies demonstrated usability of ν-SVM methodology together with genetic algorithm optimisation for retention modelling which gave better performing models than other tested approaches.

Soil chemical properties under organic and conventional crop management systems in south Poland

There is a great need to assess the impact of farming methods on soil fertility, especially in specific ecoregions. In Poland, relatively limited research has been conducted on soil quality and fertility in organic, dynamically developing agricultural systems. A comparative study on soil parameters under organic and conventional cultivation was performed in 2009. Twenty-two pairs (organic-conventional) of fields located in the south and east of Poland were chosen. All organic sites were certified. The following field crops were investigated: apple, pear, blackcurrant, carrot, beetroot, and celery. The soil granulometric composition, total organic content, total nitrogen, as well as the content of available macroelements (P, K, Ca, Mg, S), microelements (Cu, Fe, Zn, Mn, B), and trace elements (Cd and Pb) were measured. The organic farm soils had a higher level of the total organic matter (2.02%) than the conventional (1.75%). The organic system increased the total soil N level in celery and beetroot fields. Low or very low concentrations of available P in organically managed orchards were observed in individual farms, whereas excessive soil P amounts were noted for organic beetroot and celery fields. Differences in soil K concentration caused by the farming system were found only for red beet. Ca concentration was higher in the conventional than in the organic soil only for celery. There was a higher soil available Cu concentration for all of the investigated conventional vegetable fields than for the organic. The reverse was true for the apple and blackcurrant farms. The highest levels of Cd and Pb were noted in soils sampled from some organic celery fields.

Apple root system in different soil types

It is shown that the granulometric composition of soil has a considerable effect on the formation of the root system of apple trees on M9 rootstock and on their vertical location in alluvial meadow soils of Krasnodar krai.

CONTENT ADDITION TO THE STATE SOIL MAP WITH GENESIS INFORMATION OF SOIL PARENT MATERIALS AND GRANULOMETRIC COMPOSITION OF SOIL

The substantiation of the first stage of works with the digital version of the State Soil Map (SSC) on elimination of differences on different sheets in the representation of genesis of soil-forming rocks, granulometric composition of soils and rocks is given. The content and characteristics of cartographic and literary sources containing information on the genesis of soil-forming rocks. Necessity of separate showing of granulometric composition of soil-forming rocks and soils on HCC is justified. Granulometric composition of soils on GPC is shown in the C horizon, which is a characteristic of deposits on which soils are formed. Granulometric composition of soils at description on of other maps is characterized by the upper horizons. On the example of specific analytical data of soils with differentiated granulometric composition of the profile shows ways to solve the problem.Granulometric composition of soils with undifferentiated granulometric composition of the profile is identical to that of soil-forming factors.

Root uptake of 137Cs by natural and semi-natural grasses as a function of texture and moisture of soils

This work studies the dependence of 137Cs root uptake on the structure of landscape, especially on texture and moisture of soils, under natural conditions, on abandoned radiopolluted lands in Northern Ukraine. Researches were carried out on a wide range of landscape conditions, at various levels of 137Cs contamination (from 20 up to 5000 kBq m −2), with different types of soils (approx. 20 soil varieties), which differ in texture, granulometric composition, degrees of gleyization and water regime, and anthropogenic transformation. The results showed that transfer factor (TF) values of 137Cs differ 50 times for the natural grassy coenoses and 8 times for the semi-natural ones. The lowest 137Cs TF values were measured in the herbages of dry meadows at automorphous loamy soils, while the highest were observed in wetland meadows at organic soils. Finally, the correlation between 137Cs TF values and granulometric composition of soil was determined for both automorphic and hydromorphic mineral soils.

Granulometric Composition of Soil and Its Connection with Standard Distributions

Granulometric Composition of Soil and Its Connection with Standard Distributions

Controlling the quality of compaction of earth fill in the construction of high dams

1. To ensure a high rate of construction and reliability of earth dams it is suggested to check the quality of compacting coarse-grained soils of a nonpiping composition with respect to fines (e.g., with respect to particles with a diameter smaller than 1–5 mm) and soils of a piping composition — with respect to the soil as a whole. 2. In the case of a wide range of variation of the granulometric composition of soils being placed in a dam it is necessary to differentiate the requirements imposed on their density with respect to the granulometric composition. It is possible to control the granulometric composition of soils with a high degree of nonuniformity on the basis of the content of one or two characteristic fractions. 3. A check of these principles of quality control of the compaction of coarse-grained soils by the experience of constructing the Nurek dam showed their practical value.

Evaluation of cracking in rock-fill dam cores

1. Cracks in dam cores (especially high dams in narrow canyons) are a regular consequence of nonuniform deformations of various elements of the dam. 2. The formation of cracks can be predicted on the basis of analyzing the stress and strain of the dam core with consideration of the variability of soil properties in space and time and of the strength properties of soils under conditions of combined stress. 3. The data presented in the article, despite the simplified premises used, permit determining not only the possibility of crack formation, but also give a definite answer to the question under what conditions, where, and in what zones, for what types and states of soils the danger of cracking exists, and what parameters (width of opening, depth) these cracks will have. 4. The theory of brittle fracture, together with experimental investigations of the strength properties, also permit solving more complex problems of the formation of cracks. 5. To prevent cracking in cores the following measures must be taken: a) the transition zones should have sufficiently large dimensions and carefully selected composition of the soils; b) the granulometric composition of soils should be selected so as to avoid large settlements of individual zones and especially large differences in settlements of the core and shoulders; c) it is desirable to eliminate projections and irregularities in bank abutments; d) it is expedient to construct the dam uniformly without an appreciable advance of individual parts.

AGROCHEMICAL PROPERTIES MONITORING OF THE VARIOUS LANDS WITHIN THE AGROLANDSCAPE

The paper presents the results of a statistical analysis of data on long-term monitoring of the agrochemical properties of soils of various lands within the reclaimed agrolandscape. Research was conducted in 1997-2012. on the agroecological transect of the VNIIMZ polygon - a narrow field 1300 m long that intersects all the main landscape positions of the end moraine hill. During the monitoring, two rounds of agrochemical surveys of the transect territory were carried out: 1. In 1997, the initial state of the soils was investigated; 2. In 2012, the state of the soils of the output field and crop rotation array. Agrochemical parameters of soils (various types of acidity, content of plant nutrients and humus) were determined at the sampling points regularly located along the transect. The research results were statistically processed based on the STATGRAPHICS plus package. It was revealed that during the research, the same type of evolution of the agrochemical parameters of soils of different lands occurred - acidification of soils, loss of the basic elements of plant nutrition during the accumulation of humus are observed everywhere. By 2012, the spatial variability of most agrochemical parameters of soils of different lands mainly began to depend on the granulometric composition of soils. A significant difference was found in the mechanism of soil loss of potassium and phosphorus - potassium migration mainly depends on the intensity of eluvial processes in the agrolandscape, and phosphorus moves laterally along the plow sole. Based on the results obtained, it is possible to develop a system of adaptive land allocation in an agrolandscape, which allows controlling degradation processes in soils.