Loess Loam Research Articles

ENGINEERING PREPARATION OF THE SOIL BASE FOR THE FOUNDATIONS OF THE CONSTRUCTIONS OF THE DERHACHI SOLID WASTE LANDFILL

After conducting engineering and geological investigations, it became necessary to provide scientific support for construction in terms of engineering preparation of the soil base for the foundations of the structures due to extreme unsustainability in the plan and depth of the rocks. Such engineering-geological conditions significantly impact the choice of foundation structures and the justification of measures to reduce or eliminate the negative effect on the environment and the development of dangerous geological processes and phenomena. We thoroughly studied the deformation and strength properties of the supporting soil layers and developed recommendations for their engineering preparation and improvement of the indicators. Bulk soil is present in local depressions: construction debris, sand, and compacted loam. Based on the analysis of physical and mechanical properties, we could conclude that this soil cannot be used as a soil base for the foundations of buildings due to its loose composition and enrichment with organic substances and must be completely replaced during the production of earthworks. They can be used as a basis for laying engineering networks. After excavation pits for individual columns, before setting up the preparation, it is necessary to carefully inspect the soil foundation to ensure that it is the same engineering and geological element specified in the project. The soil base of the foundations is redeposited subsidence loess loams, which have mostly lost their subsidence properties, but local inclusions with subsidence properties have remained in the thickness of these soils. If there are lenses of soils in the soil base with indicators of physical and mechanical characteristics that are lower than those adopted in the project and that have a thickness of less than one meter, they should be removed and replaced with sand or sand-crushed soil with layer-by-layer compaction and compaction quality control. Doing so will create the same soil conditions for the building foundation. The performed scientific and technical support of the construction made it possible to choose a method of technical soil reclamation—partial replacement of weak soils with sand and crushed stone, which, after layer-by-layer compaction, can withstand a significant load and stability under vibrational influences. Keywords: landfills, solid household waste.

Sedimenty spodního badenu na lokalitě Zaječí hora

Lower Badenian deposits were newly exposed at Zaječí hora Hill (Brno city). Sedimentological and paleontological study of the succession recognised two facies associations. The lower one was formed by the lower Badenian clastic deposits known locally as “Brno sands”. The upper one is formed by the lower Badenian offshore clays known as “tegel”. The Neogene beds were covered by Quaternary loess loam. Lower Badenian succession is interpreted as progradation of the Gilbert-type delta foreset into relatively deep basin followed by the flooding of the area by the open sea. The position of the locality close to a steep basin margin was prone to reflect role of local factors influencing the depositional processes and conditions.

STUDY OF TRITIUM MIGRATION AND RETENTION MECHANISMS IN THE GEOLOGICAL ENVIRONMENT (BY THE EXAMPLE OF THE KYIV RADIOACTIVE WASTE STORAGE FACILITY)

Radioactive waste storage facilities (RWSF) are a potential source of tritium in the biosphere. Engineered concrete constructions are not sufficiently reliable forasmuch as water leaks contaminated with tritium from the storage facilities into the geological environment has been detected. The barrier properties of the natural environment at the storage sites are determined by the ability to absorb and retain heavy isotopes of hydrogen during a considerable period of time and thus exclude its circulation in the biosphere. Various elements of the natural ecosystem take part in the absorption of tritium – the geological environment, soil organic matter, annual and perennial vegetation, micro- and macrobiota. A certain part of tritium in the gaseous and aerosol form is released into the air. The highest concentrations of tritium are recorded in the area close to the concrete radioactive waste (RW) storage facilities, where the vapor-gas emanation plume is least dispersed. With distance from the storage facilities, the tritium concentration in the soil humus layer significantly decreases due to the spatial dispersion of the tritium in the atmospheric plume. Tritium from the air enters the soil with the atmospheric precipitation and is partially retained in the humified layer of the soil. Most of the tritium from the atmospheric precipitation is transported by the vertical infiltration flow through the sedimentary layers represented by loess sandy loams and loams, where it is finally retained. In the area close to RWSFs, the concentration of heavy hydrogen isotope in pore, interstitial and film water (1 fraction) is up to 87 % of its total content in an elementary block. In the more tightly bound forms (2 and 3 fractions), it is 9 % and 4 %, respectively. Farther from the RW storage facilities in the predominant air flow direction, the tritium concentration in free water decreases to 75 %. In this area, more intensive redistribution of tritium between the structural sites is observed. At the more distant monitoring points (wells), from 25 % to 37 % of the total tritium amount in the soils is retained in more tightly bound forms in the structure of rock-forming, mainly clay minerals

Study of the efficiency of sweet potato growing in the Forest-Steppe of Ukraine by different methods of soil mulching

Sweet potato (Ipomoea batatas L.) is a new crop for soil and climatic conditions of Ukraine, the active implementation of which is hindered by the lack of recommendations on technological aspects of cultivation. One of the important technological measures for growing sweet potatoes is the use of soil mulching, which improves the water regime and regulates the thermal regime of the soil; prevention of weed growth and growth of sweet potato shoots to the soil. Thus, the aim of the research is to determine the efficiency of growing sweet potatoes in the Forest-Steppe of Ukraine by different methods of soil mulching.
 Field research was carried out on typical low-humus light loamy chernozem on loess loam.
 It was noted, that when growing sweet potatoes on ridges, the introduction of mulching the soil with black polyethylene film provides more active growth of the vegetative mass throughout the growing season (5.33 shoots/plant with a total length of 252.1 cm), while growing without ridges has a positive effect on plants growth due to the general absence of mulch (2.53 shoots/plant with a total length of 107.8 cm).
 The use of ridges and mulching the soil with black polyethylene film causes the yield of sweet potato tubers at 34.8 t/ha, while the mulching of the soil with straw, the yield was 18.3–21.9 t/ha, without mulching – 13.0–17, 1 t/ha. Mulching with black polyethylene film ensures the accumulation of vitamin C and starch in sweet potato tubers. When growing the culture on ridges by this method of mulching, the maximum level of vitamin C according to the experiment (4.78 mg/100 g) and starch (11.73 %) was noted.
 The introduction of mulching and ridge formation involves additional material and labor costs, but helps to reduce weed control and tuber digging costs. When growing sweet potatoes on ridges with mulching with black polyethylene film, the minimum additional labor costs for the formation of a unit of yield (1.95 man-minutes/kg of tubers) were noted, while without mulching and without ridges this figure was 6.76 man-minute/kg

The problems of assessing radon hazard of development sites in the Russian Federation and the Czech Republic

The problem associated with the risk assessment of radiation caused by the accumulation of radioactive radon gas in closed premises has not been solved to date. Additionally, there is no consensus regarding the set of parameters that should be used for radon hazard assessments of buildings. This paper presents the results of measurements related to radon assessments in the Russian Federation (radon flux density; RFD) and the Czech Republic (volumetric activity of radon in the soil air measured at a depth of 0.8 m and soil gas permeability). In the Russian Federation, RFD was measured in the city of Tomsk on the surface of loess loam using accumulation chambers and carbon adsorbers. In the Czech Republic, the volumetric activity of radon in the soil air and gas permeability were measured by the complexes RM-2 and RADON JOK, respectively, at a testing site located approximately 180 km southwest of Prague and characterised by brown forest and mountain sub-ash soils (cambisols) of the Bohemian Massif.The observed high variability of gas permeability in surface rocks and the radon flux density measured on the ground surface casts doubt on the reliability of assessments of radon hazard risks in the built-up areas. Based on the analysis of the results, other approaches are proposed for conducting radon hazard assessments of built-up areas.

Anorthite Ceramic Based on Loess Loam

Anorthite Ceramic Based on Loess Loam

Soil Formation, Subaerial Sedimentation Processes and Ancient Cultures during MIS 2 and the Deglaciation Phase MIS 1 in the Baikal–Yenisei Siberia (Russia)

The time of Sartan glaciation in the Baikal–Yenisei Siberia, is comparable with that of MIS 2 and the deglaciation phase MIS 1. Loess loams, aeolian–colluvial sands and sandy loams represent subaerial sediments. There are four subhorizons (sr1, sr2, sr3 and sr4) in the Sartan horizon (sr). Sedimentary and soil-forming processes at different stratigraphic levels are considered. Differing soil formation types of cold periods are distinguished. Soils of the interstadial type with the A-C profile are represented only in the Early Sartan section of this paper. The soils of the pleniglacial type are discussed throughout the section. Their initial profile is O-C, TJ-C and W-C. Plant detritus remnants or poor thin humus horizons are preserved in places from the upper horizons. We propose for the first time for the interphasial soil formation type of cold stages to be distinguished. This is represented in the sections by the preserved BCm, BCg, Cm and Cg horizons of 15–20 cm thick. The upper horizons are absent in most sections. According to the surviving fragments, these were organogenous (O, TJ and T) and organomineral (AO and W) horizons. The sedimentation and soil formation features are considered from the perspective reconstruction of the Sartan natural and climatic conditions. Buried Sartan soils often contain cultural layers. Soil formation shows a well-defined periodicity of natural condition stabilization, which allowed ancient populations to adapt actively to various situations. Archaeologists’ interest in fossil soils is based on the ability of soils to “record” information about the natural and climatic conditions of human habitation.

Системи удобрення батату (ipomoеa batаtas) в умовах Лівобережного Лісостепу України

Системи удобрення батату (ipomoеa batаtas) в умовах Лівобережного Лісостепу України

Методика расчета потерь воды из оросительных каналов

The aim of the article is to develop a method for calculating water losses from irrigation channels in determining the permeability of rock in the zone of filtration flow on the basis of the law of infiltration A.N. Kostyakov using the results of studies of free filtration from pits and foundation pits in loess loams.
 Pressure movement of water in irrigation canals is subject to the laws of two-phase flow, in which – in contrast to the Darcy law for the zone of saturation plays an important role, the volume and its change in time. The filtration rate (VF) increases with increasing rock moisture (θ) along the S-curve, while the pressure gradient (I = dh/dz) decreases.
 The dependences of these parameters on the pressure are represented by power functions, and their product CDP = VFI does not change in time and can serve as a characteristic of the filtration flow under the channel. When installing paired piezometers near the water chore line in the channel and determining the graph I(t) by the value of the twophase flow constant CDP, it is possible to calculate the filtration rate at a number of times and the water losses during unsteady filtration.
 Water losses from the channels at equilibrium humidity increases with increasing head according to the formula A.N. Kostyakova, in which the water permeability of rocks is characterized by a steady filtration rate at a head of 1.0 m, and the gradient is the function of pressure.
 The application of the proposed method of calculating losses in the design of irrigation systems will increase the reliability of the justification of the volume of anti-filtration measures and the forecast of the groundwater level.

A new approach to the problem of assessing the radon hazard of building sites

Radon and its daughter products create more than half dose from all natural radiation sources. The radon entering the buildings is emitted mainly from soils lying at the base of the foundation. Therefore, before carrying out construction work, the radon hazard of the construction area are determined. In the Russian Federation, the radon hazard of an area can be determined using radon flux density measured on the soil surface. To date, radon researchers came to the conclusion that the geology of the territory affects the amount of radon released from the soil surface. However, there are almost no studies devoted to the release of radon from the surface of various soil types. The paper presents the measuring results of the radon flux density on the surface of loess loams, porcelain clay, argillaceous slate, sand-and-gravel sediment, rocky limestone, clayey limestone, andesite-basalt porphyrite and quartzrock. The measurements were carried out by the accumulation chamber method using the Alfarad Plus measuring complex. Also, measuring radium activity concentration and soil moisture were carried out. The research demonstrates that, depending on the type of soil, the amount of radon emanating from its surface differs by more than an order of magnitude. The largest values of radon flux density of ~ 800 mBq∙m-2s-1 were recorded for andesite-basalt porphyrite and quartzrock. The smallest ones of ~ 40 mBq∙m-2s-1 were registered for loess loams and argillaceous slates. For soils consisting of small sand and clay grains, a rather strong dependence of the radon flux density on soil moisture was found. When measuring soils with low moisture (2-6%), a proportional dependence of the radium activity concentration on the amount of radon emanating from the soil surface is not observed. The types of soils that lie at the foundations of the buildings, and their physical properties can be used as the basis for classifying building sites according to the degree of radon hazard. Relevant information may be provided by organizations engaged in design and survey work at building plots. The approach proposed in the work for assessing radon hazard will allow avoiding labor-intensive measurements of radon and thereby reduce the financial, material and labor costs of building construction.

Traits of the Neolithic-Eneolithic archaeological layers’ formation at the sites of Algay and Oroshaemoe in the low Volga basin (Low Povoljie)

The Low Volga basin is an important area for the study on the genesis of Neolithic and Eneolithic archaeological cultures in Eastern Europe. Until now well stratified Neolithic-Eneolithic sites had not been found in the Low Volga (Low Povoljie) region. This has been a cause of serious discussion about the periodisation, genesis and interaction between cultural groups during the Late Stone Age in this area. Excavations of new open sites of Algay and Oroshaemoe began in 2014. Both sites are unique for the Low Povoljie. It is important that the archaeological layers are within loess loam and they are interlayered with sterile natural layers. This fact precludes a mixing of artefacts of different ages. Most of the artefacts and ecofacts found in a clear stratigraphic context allow for a presentation of the detailed characteristics of the Orlovskaya Neolithic culture, and the Cis-Caspian and the Khvalynskaya Eneolithic cultures. For the first time, reliable data have been obtained for a periodisation of the Neolithic-Eneolithic of the Low Povoljie. A set of radiocarbon dates for all archaeological layers allows for a determination of the precise chronological frameworks of Neolithic-Eneolithic cultures in this region. The geochemical analysis of archaeological layers and sterile interlayers made possible a reconstruction of climatic characteristics for different periods of the Holocene. The processes of development of archaeological layers in the periods of the Orlovskaya and the Cis- -Caspian cultures were considered.

Розвиток рослин огірка посівного бджолозапильного гібриду Янос f1 залежно від рівня мінерального живлення

Розвиток рослин огірка посівного бджолозапильного гібриду Янос f1 залежно від рівня мінерального живлення

Diversity, dynamics and ecological analysis of flora of reclaimed soil

Abstract The flora of vegetation cover of sod-lithogenic soil on loess loams was studied at a reclaimed site in the Nikopol manganese-ore basin. The control site is located on the black soil of the steppe area. The species composition of plants was studied in both sites annually for three years. Ecological analysis of the flora was carried out according to Raunkiaer’s system of life-forms and Belgard’s system of ecomorphs. It has been established that the floristic composition on the reclaimed site is significantly poorer than that of the steppe site. The reclaimed site was found to be have fewer species and a smaller number of families. The comparative inconstancy and dynamism of floristic composition on reclaimed soil is shown. The reclaimed ecosystem is distinguished by a significant share of the participation of annual and biennial plant forms. This indicates the anthropogenic transformation of the vegetation cover of the reclaimed soil. Also, a distinctive feature of the reclaimed soil flora is the smaller number of ecological groups of species. Such groups are united according to the ecological optimum to one of the environmental parameters.

Стійкість угруповань молюсків техноземів Нікопольського марганцеворудного басейну

The regularities of the stability of terrestrial molluscs community in the Lyapunov sense that there in artificial soil-like structures within the Nikopol manganese ore basin, namely pedozems and sod-lithogenic soils on red-brown clay, gray-green clay and loess. The studies were conducted during the 2012-2014 biennium. on site remediation of Nikopol manganese ore basin in Pokrov. The basis for describing the dynamics of communities are taken cascading Lotka-Volterra equations. It was established that between the number of species there is a positive correlation between the presence of which can be attributed to common features of ecology of terrestrial molluscs in general. The nature of interspecies relationships has its own specificity, depending on the type of biogeocoenosis. The study found the most sustainable communities of terrestrial molluscs are formed on the sod-lithogenic soils on loess loam and least stable - on sod-lithogenic soils to gray-green clays and pedozems. For sod-lithogenic soils found the biggest off-season difference of sustainability indicators. The most sustainable communities in the spring and summer, and the least stable - in the summer-autumn period. Most regular factor in the sustainability of communities is negative autocorrelation kinds of communities, most often it is the dominant form of B. cylindrica. Interspecific interactions have both stabilizing and destabilizing effect, which is the specificity of each type of community dynamics tehnozems. A promising area of research can be considered as an assessment of the functional role of terrestrial molluscs community structure mezopedobionts tehnozems. The knowledge of the dynamics of terrestrial molluscs community will help address issues of management functional properties rekultozems models.

Вплив лісових насаджень плантаційного типу на показники родючості лісових ґрунтів в умовах Західного Лісостепу України

Між насадженнями різного складу та родючістю ґрунту існує тісна взаємодія, яку можна корегувати, змінюючи участь порід у складі деревостану. Питання особливо актуальне з погляду запровадження плантаційних лісових насаджень на місці низькопродуктивних деревостанів. Тому вивчення змін показників родючості ґрунту у системі – плантаційні насадження → ґрунт → корінний деревостан, є надзвичайно важливим чинником забезпечення високої продуктивності та біотичної стійкості лісових фітоценозів. 
 Досліджені темно-сірі опідзолені ґрунти на лесоподібному суглинку характеризуються високим лісорослинним потенціалом, результатом якого є формування чистих і мішаних насаджень модрини та ялини за високими класами бонітету – від І до Іс. Водночас значення показників родючості ґрунтів (вміст гумусу та рухомих сполук NPK) під цими насадженнями відрізняються.
 Вміст гумусу у ґрунтах під насадженнями за участю ялини коливається в межах від 0,32 до 4,52 % та в середньому становить 1,80 %, що нижче, ніж під насадженнями модрини – 0,32-9,32 % та 2,17 % відповідно.
 Склад насаджень впливає на вміст у ґрунті усіх досліджених елементів живлення. Середній вміст легкогідролізованого азоту у ґрунтах під насадженнями за участю ялини є нижчим (5,68 мг/100 г ґрунту), ніж за участю модрини (7,10) та більш амплітудно знижується вниз по профілю. Так, його середній вміст у Не-горизонті становить 9,63 мг/100 г ґрунту, в НІ – 4.87, в І – 2,52, а під насадженнями за участю модрини – 10,41, 6,51 та 4,24 мг/100 г ґрунту відповідно. 
 Середній вміст рухомих сполук фосфору в обох групах насаджень є доволі подібним –5,93 мг/100 г ґрунту за участю ялини та 5,80 – модрини. Водночас в І-горизонті у культурах з модриною він значно вищий, ніж у культурах з ялиною – 7,70 проти 2,64 мг/100 г ґрунту, що сприяє росту модрини за Іb-Iс класами бонітету. Характер розподілу обмінного калію за профілем ґрунту принципово відрізняється. Так, якщо під насадженнями за участю модрини його найвищий вміст (9,50 мг/100 г ґрунту) зафіксовано в Не-горизонті, то за участю ялини – у І-горизонті (11,85), що свідчить про інтенсивний прояв процесу кислотного гідролізу у ґрунтах під впливом опаду ялини. Проте середньопрофільний вміст обмінного калію у ґрунтах під обома групами насаджень є доволі подібним – 8,90 мг/100 г ґрунту у культурах з модриною та 9,17 – з ялиною.
 Загалом чисті ялинові та модринові культури в умовах свіжого і вологого груду Західного Лісостепу України не виявляють негативного впливу на показники родючості темно-сірого опідзоленого ґрунту. Водночас сприятливіші поживні властивості формуються у ґрунтах під насадженнями за участю модрини, які, своєю чергою, забезпечують найвищий рівень їх продуктивності, що необхідно брати до уваги під час проектування складу лісових культур плантаційного типу.

PETROFYZIKÁLNÍ CHARAKTERISTIKA SPRAŠE A FOSILNÍ PŮDY V HLINÍKU U LITOVLE

Loess-paleosol sequences are an important source of terrestrial paleoclimatic proxy-data. Quaternary loess and loess loam cover the most of surface of the Upper Moravian Basin. Samples from loess-paleosol sequence in vicinity of Litovel town were studied using magnetic susceptibility, spectrophotometry and laser granulometry. Obtained petrophysical data were compared with detailed lithological description of section and geochemical characteristics determined by ED-XRF method. The results contribute to interpretation of paleoclimate in the Upper Moravian Basin during the last glacial.Section with total thickness of about 5 m is formed by loess in its upper part. This layer covers several soil horizons. It is most probably youngest loess deposit formed during the last glacial maximum. Petrophysical and geochemical data and comparison with nearby sites indicate relatively humid cold tundra conditions with bush-steppe vegetation during deposition of loess. Lithological features, position below youngest loess deposit and petrophysical and geochemical data allow interpretation of soil horizons as PK I. Low values of magnetic susceptibility indicate formation of soil in arctic interstadial conditions with higher humidity compared to interstadial average. Values of magnetic susceptibility of PK I are equal or even lower than in overlaying loess which doesn´t correspond with usual behaviour of magnetic susceptibility in loess-paleosol sequences in the Czech Republic. It could be explained by formation of soil horizons in cold interstadial climate (low production of oxi/hydroxide of Fe) supplemented by increased humidity and hence, intensive illimerization process (clay migration and Fe-minerals depletion).

Strength Parameters of Sagged Loess Soils during the Soaking

It should be noted that the change in the strength parameters of loess soils when they are saturated with water differs from the conventional soils not only in quantity, but also in quality. The article contains the results of a study of the effect of soaking time on the strength of loess loam.

Ecology of soil algae cenoses in Norway maple plantation in the recultivated territory of the Western Donbas (Ukraine)

The problem of the degradation of land ecosystems and their underlying basis – the soil – has a global character. In some regions of Ukraine, such as the Western Donbass, it becomes particularly topical. The damaged areas formed during coal mining are restored through reclamation. One of its directions is forest reclamation. Soil algae constitute an active autotrophic part of the microbiota. They are connected with all its autotrophic, heterotrophic components and with the soil. They play a great role in the accumulation and transformation of organic matter, contributing to the creation of soil fertility. This explains the importance of algae in the process of restoration of damaged soils. Algae participate in the formation of primary products for primary consumers of such soil saprophages as two-bipartite petioles, woodlice, earthworms, collembola, oribatei. These animals act as a natural soil-protecting biological factor, as well as the factor of naturalization of soils in the restoration of damaged areas. They cause redistribution of algae communities composition as a result of their selective eating, thus affecting the number of their communities. The selection of soil samples and forest litter has been carried out in the plantations of Norway maple in the experimental-production site of forest reclamation in the territory of the Western Donbas (Ukraine). The structure of the domination of algae complexes, the vital forms of the representatives of the coenoses of soil algae in the plantation of Acer platanoides L. on various stratigraphic variants of piled edaphotopes – on a variant with a potentially fertile terrain (non-humous loess loam) and on several chernozem variants with different stratigraphy has been studied. The representatives of green algae ( Chlorophyta ) predominate in the investigated re-cultivated area in the plantations of Norway maple. The participation of green algae in the composition of soil algae groupings shows the sylvatizative role of the tree plantations in the restored territories. In the plantations of Norway maple on the various stratigraphic variants of piled edaphotopes, an increase in the number of species from 8 in the area with the fill of loess loam up to 15 in a chernozem variant with a half-meter layer of sand has been noted. In general, for maple plantations on chernozem fills, a larger number of species (from 10 to 15) has been observed compared to the maple plantation on the loess loam fill. On the one hand, the small species variety indicates very rough conditions for the existence of soil algae flora, on the other hand, the appearance and occurring of species characteristic of forest ecosystems, indicates the processes of their naturalization in the re-cultivated territories.

Use of arable land with agroecological assessment of soils

Growing crop production with ignoring the quality of arable land leads to lower crop yields and unreasonable costs. There are areas of waterlogged, marshy, eroded soils or soil with low humus content and low available form for plant of nutrients in intensive use of land, that is leased or owned by modern agricultural companys. These lands have different area and configuration of soil contours and it is the cause of complicated planning of the fields’ boundaries. The purpose of representing data in this article is the justification of the rational use of arable land on condition detailed analysis of soil properties. Because the land management is the basis for optimization of agricultural production in a certain area. In order to obtain indicative results, the territory with complex structure of soil cover and with soils, which differ greatly in their physical and chemical properties and conditions of soil formation, was chosen as the object of research. Soil conditions were analyzed by natural indicators such us groundwater levels, granulometric composition of soil, nutrients concentration that are available for plants, acidity of soils. The explored area has flat relief with moderate climate and insufficient humidification in separate periods. Soils’ parent material: alluvial deposits, loess loam, deluvial deposits. There are 11 groups of soils on the research area of 1272.4789 ha. Among them Haplic Chernozem, Albic Luvisol, Gleyic Chernozem, Mollic Gleysol, Luvic Greyic Phaeozem, Endogleyic Arenosol and Histic Gleysol. The Gleysols occupy a large area of surveyed land (106 hectares). These soils have a very poor water-air mode and suffer from drought or waterlogging in some periods. In order to achieve the purpose of the work an existing methodology for the soils grouping into classes for the suitability of growing agricultural crops was used. Also the scale of soil evaluation for the Ruzhinsky agricultural region was applied. The article represents data of soil classification into classes of suitability by ten classification items. It is established that not the whole area of arable land is suitable for growing wheat. The estimated yield of winter wheat was calculated on the basis of soil's properties. Winter wheat is the demanding plant to soil and climate condition. This is the cause there are low productivity of this plant on clay soil types and soils that have sandy granulometric composition. The estimated yield of winter wheat on Histic Gleysol and Mollic Gleysol is 6.8 centner/ha and on Endogleyic Arenosol is 12.5 centner/ha. Inclusion such tapys of soils in fields area leads to a decrease the yield of winter wheat crops. This is difficult for land use in case low fertility soils are situated in higher quality soils’ area. This situation is inherent territory of Polisya and south part of Ukrainian Lisostep zone. As a result of researchi it was realized that Haplic Gleysol occupy small areas (between 0.1-0.3 ha). These soils are located near Endogleyic Arenosol that don’t suffer from excessive moisture and need another approach of land use. The importance of taking into account the properties of soils is proved. The approach of land use of arable land is proposed. Keywords . S uitability of soils, groups of soils, wheat crop, land use .

Rhizosphere Competence and Biocontrol Effect of Pseudomonas sp. RU47 Independent from Plant Species and Soil Type at the Field Scale.

Biocontrol inoculants often show inconsistency in their efficacy at field scale and the reason for this remains often unclear. A high rhizosphere competence of inoculant strains is assumed to be a key factor for successful biocontrol effects as the biocontrol strain has to compete with the indigenous microbial community in the rhizosphere. It is known that many factors, among them plant species and soil type shape the rhizosphere microbial community composition. However, microbial community composition in the rhizosphere can also be influenced by the presence of a pathogen. We hypothesized that plant species, soil type, and a pathogen affect the rhizosphere competence of a biocontrol strain and its biocontrol effect against a soil-borne pathogen. To test the hypothesis, we used an experimental plot system with three soil types (diluvial sand, alluvial loam, loess loam) kept under similar agricultural management at the same field site for 12 years. We investigate the rhizosphere competence of Pseudomonas sp. RU47 in two plant species (potato and lettuce) and its biocontrol effect against Rhizoctonia diseases. The colonization density of a rifampicin resistant mutant of RU47 in the rhizosphere of both crops was evaluated by plate counts. Bacterial community compositions were analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments amplified from total community DNA. The inoculant RU47 was able to colonize the rhizosphere of both model crops in a sufficient density and to reduce disease severity of black scurf on potato and bottom rot on lettuce in all three soils. DGGE indicated that RU47 affected the bacterial community composition stronger in the rhizosphere of lettuce than in the potato rhizosphere. In contrast, the effect of the pathogen Rhizoctonia solani on the bacterial community was much stronger in the rhizosphere of potato than in the lettuce rhizosphere. A significant effect of RU47 on the Pseudomonas-specific gacA fingerprints of the rhizosphere was only observed in lettuce in alluvial soil. The soil type and plant species independent biocontrol effects of RU47 and its minor influence on the indigenous bacterial community composition might be important criteria for the registration and use of RU47 as biocontrol strain.