Bioindication of oil-contaminated grey-meadow soils

Background. Physiological characteristics of the biofuel plant Miscanthus × giganteus J. M. Greef, Deuter ex Hodk. & Renvoize are currently attracting much attention due to its phytoremediation potential. The aim of this work was to study the content of photosynthetic pigments in the leaves of M. giganteus, the accumulation of metals in the rhizosphere and aboveground organs, as well as the morphological parameters of plants cultivated on oil-contaminated soil and exposed to treatment with humic preparations. Materials and Methods. During field experiments, five experimental plots (PC and P1–P4) with an area of 1 m2 were laid out on podzol soil in the territory adjacent to the Starosambirske oil field. The PC plot was not subjected to any experimental treatment. The soil in plot P1 was planted with M. giganteus rhizomes; the soils in plots P2–P4 were contaminated with 10 L/m2 of crude oil and then planted with M. giganteus rhizomes. Before planting the rhizomes on plots P3 and P4, these were soaked in solutions of Fulvital® Plus Liquid and Humifield® Forte, respectively. During the growth period, the plants were sprayed twice with humic preparations. Shoot height and leaf width, a- and b-type chlorophyll (Chla and Chlb, respectively), total chlorophyll (Chla+b) and carotenoid concentrations were measured using standard methods. The content of metals (Ca, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn) in soil and plant samples was assessed by X-ray fluorescence analysis using an Elvax Light SDD Analyzer. Results. The cultivation of M. giganteus on oil-contaminated soil did not affect shoot height or leaf width of plants, but it reduced the content of Chla, Chlb, Chla+b and carote­noids in plant leaves. Treatment of plants with humic preparations led to an increase in pigment concentrations in the leaves at different growth periods. Oil-contaminated soil planted with M. giganteus showed elevated levels of Cr and Ni. The cultivation of M. giganteus treated with Fulvital® Plus Liquid resulted in increased Ca, Mn and Ni contents in rhizosphere soil of an oil-contaminated plot. Growing M. giganteus on oil-contaminated soil resulted in significant decreases in Ca, Cr, Fe, K, Mg, Ni and Zn concentrations in plant stems. Treatment with humic preparations increased the content of the mentioned metals in the stems and the concentration of Mg and Ni in the leaves of plants from oil-contaminated soil compared to those in untreated plants. According to the bioaccumulation factor (BF) values, M. giganteus leaves have a high accumulation potential for Ni and Ca (BF>1), a medium accumulation potential for Mg, K and Cr (BF from 0.1 to 0.32) and a low accumulation potential for Fe and Zn (BF<0.1). The BF values of metals in leaves and stems decreased when plants were grown on oil-contaminated soil. Conclusions. Humic preparation treatment has a positive effect on the physiological parameters of M. giganteus grown on oil-contaminated podzol soil. The ability of M. giganteus to extract Ni from soil may mediate the plant’s phytoremediation potential. In this regard, the cultivation of M. giganteus in combination with its treatment with humic preparations will be promising on lands contaminated with oil and petroleum products.

Актуальность исследования. Наибольшая антропогенная нагрузка, связанная с эксплуатацией природных ресурсов в Томской области, приходится на нефтегазодобывающую промышленность. Геоэкологический анализ территории показал, что наиболее уязвимыми участками являются северные административные районы, при этом основной фактор нефтяного загрязнения почв – аварии на трубопроводах. Биоремедиация является низкозатратным и экологичным методом восстановления нарушенных территорий. Эффективный подход к биоремедиации нефтезагрязненных почв заключается в выделении аборигенных микроорганизмов-деструкторов углеводородов и создании биопрепаратов на их основе. Цель: разработать промышленный консорциум на основе аборигенных углеводородокисляющих бактерий из почв Севера Томской области и оценить его эффективность для биоремедиации нефтезагрязненных почв. Объекты и методы. Культуры аборигенных углеводородокисляющих микроорганизмов получены в селективных условиях из образца почвы Советского месторождения нефти Томской области, загрязненной сырой нефтью. Выделенные штаммы идентифицировали с использованием молекулярно-генетических методов на основе анализа последовательностей гена 16SрРНК. Изучение физиологических и биохимических свойств изолятов выполняли стандартными методами, морфологию клеток изучали микроскопически. Для оценки эффективности биопрепарата на основе выделенного штамма проводили полевые испытания на нефтезагрязненных участках. Количественный химический анализ на суммарное содержание нефтепродуктов в почве выполняли флуориметрическим методом. Результаты. В ходе исследования из нефтезагрязненных почв в Томской области выделены и охарактеризованы 3 новых штамма углеводородокисляющих бактерий, принадлежащие к родам Acinetobacter и Oleomonas. Аборигенные микроорганизмы характеризуются сниженными оптимумами температуры и рН по сравнению с типовыми штаммами. На основе выделенных микроорганизмов разработан коммерческий биопрепарат «Абориген», предназначенный для биоремедиации нефтезагрязненных почв и ветландов. Экспериментальное восстановление нефтезагрязненных почв с помощью препарата аборигенных микроорганизмов-биодеструкторов позволило значительно сократить сроки по сравнению с самостоятельным восстановлением почвенного покрова в ходе естественных процессов. Полевые испытания показали высокую эффективность деструкции нефти под действием биопрепарата – в среднем по восьми опытным участкам суммарное содержание нефтепродуктов в почве было снижено в 12,4 раз за три месяца.

The potential use of MedicagoL. in the phytoremediation of oil-contaminated gray-brown soils on the Absheron Peninsula is explored. The number of heterotrophic microorganisms in the rhizosphere and rhizoplane of plants, as well as the number of microorganisms of physiological groups growing in contaminated soil, was significantly higher than in uncontaminated soil. Their activity accelerates the self-purification of hydrocarbons from oil-contaminated soils. The total hydrocarbon content in the alfalfa rhizosphere was only 1.5 g/100 g of soil, compared to 7.9 g/100 g of soil, confirming the effectiveness of Medicago L. in the cleanup and restoration of oil-contaminated soils.


 
 
 In the research, the optimization of natural and anthropogenic landscapes on the northeastern slopes of the Lesser Caucasus is investigated in order to achieve sustainable development. The research is oriented towards three main directions of landscape planning: ecological balance, continuous management of natural processes, and preservation of natural components through protected areas. The NDVI (Normalized Difference Vegetation Index) was used to study the dynamics of changes in natural landscape characteristics. The comparative analysis of Landsat 5 and Landsat 8 images demonstrates a strong correlation between landscape changes and the structural and functional characteristics of the region’s agrolandscapes. Although the terrain and favorable climate of the area create suitable conditions for the development of agriculture, significant transformations in NDVI occur due to seasonal changes. Human activities, especially agriculture, have an impact on the increase in the area of non-vegetated lands. Seasonal comparisons highlight the necessity of considering ecological aspects in planning land use on the northeastern slopes of the Lesser Caucasus to ensure sustainable landscape management and environmental conservation. In the researched area, there are existing problems such as desertification, soil degradation, and deforestation. Natural and ecological conditions are assessed by considering the differentiation of the relief, anthropogenic activities, and compliance with ecological principles. Based on this evaluation, modern landscapes are classified into groups according to their ecological stress levels. Protected areas, including Goygol National Park, play a crucial role in preserving the ecological integrity and biodiversity. Research in the direction of landscape optimization and planning aims to enhance natural biodiversity and the ecological potential of the region. The research emphasizes the necessity of eliminating intensive anthropogenic impacts in various areas that negatively affect natural landscapes. Landscape optimization and planning are highly important to ensure ecological balance and sustainable development. During the research, the analysis of theoretical issues related to geographic forecasting, proposed with the purpose of effective implementation of landscape planning, has shown that the principles and methods of forecasting in the research area should be based on the structural-dynamic characteristics of natural and anthropogenic landscapes. Implementing landscape planning measures emphasizes the understanding of landscape changes and contributes to environmental conservation and the importance of sustainable development.
 
 

The accelerated development of energy resources around the world has substantially increased forest change related to oil and gas activities. In some cases, oil and gas activities are the primary catalyst of land-use change in forested landscapes. We discuss the challenges associated with characterizing ecological change related to energy resource development using North America as an exemplar. We synthesize the major impacts of energy development to forested ecosystems and offer new perspectives on how to detect and monitor anthropogenic disturbance during the Anthropocene. The disturbance of North American forests for energy development has resulted in persistent linear corridors, suppression of historical disturbance regimes, novel ecosystems, and the eradication of ecological memory. Characterizing anthropogenic disturbances using conventional patch-based disturbance measures will tend to underestimate the ecological impacts of energy development. Suitable indicators of anthropogenic impacts in forests should be derived from the integration of multi-scalar Earth observations. Relating these indicators to ecosystem condition will be a capstone in the progress toward monitoring forest change in landscapes undergoing rapid energy development.

Natural disasters, such as postglacial landslides in Alpine valleys, recurrently reshape the natural and human landscape, impacting on settlements, land-use and architecture. Historical catastrophes were sometimes narrated and painted, so that in these cases chronicles and artistic representations can be integrated to geological, geomorphological, geophysical and archaeological data to describe the co-evolution of the natural and cultural landscape. This is the case of the Piuro landslide that in 1618 almost completely buried this renown and rich trading town in the Bregaglia Valley (Italy), on the way to the relevant alpine Maloja pass. Since it totally modified the valley floor, the catastrophe represents a turning point that permits to i) attempt the 3D reconstruction of the natural and archaeological landscape before and immediately after the disaster, ii) unravel the post-1618 increments of evolution of the natural landscape and settlements, iii) retrieve the memory of the area that underwent the disaster. To accomplish these aims we integrated: a new detailed DTM; a reconstruction of the relative chronology of burial, erosion and stabilization of the landforms after natural and anthropic processes pre- and post-dating the 1618 landslide; some subsurface stratigraphic logs and images based on new boreholes and geophysical surveys; age determinations based on radiocarbon and archeological/historical data; chronicles and paintings depicting the Piuro area before and after the disaster. The images we could draw show how human settlements were continuously controlled by the occurrence of landslides and other catastrophic processes like debris flows, before and after the 1618 landscape turning point. In the valley center we could detect a pre-1618 landslide body, whose mega-boulder reliefs were settled at least since the 4th – 5th century AD, at present buried below the Middle-ages and Renaissance Piuro villages. These landslide bodies provided also favorable settings for food preservation, whose memory and usage survived and reached the present-day under the vernacular denomination of “crotti”. At the millennial time scale no stable geomorphological surfaces do exist on the valley floor and lower slopes, since we could map the chronology of building of the debris flow-fan lobes, demonstrating how they evolved before and after the 1618 landslide, burying and/or being buried by the two major landslide bodies and interfingering with the trunk river alluvial sediments. Radiocarbon age determinations, archeological findings and the known ages of historical buildings permitted to recognize the geomorphological surfaces that remained stable on a shorter, secular, time scale, where the settlements could resume still competing with catastrophic processes that led to repetitive burial of several buildings during the last three centuries. Based on these results we could draw the 3D models of the Piuro area predating and immediately postdating the 1618 catastrophe. Historical paintings and chronicles largely confirm the relative chronology of landscape changes that we propose.The present work was co-funded through the EU, Regional Development European Fund, by Italian State, Helvetic Confederation and Cantons under the Interreg V-A IT-CH 2014-2020 Cooperation Program - A.M.AL.PI.2018 “Alpi in Movimento, Movimento nelle Alpi. Piuro 1618-2018", ID 594274 – Axis 2 “Cultural and natural enhancement”.

The aim of this work was to isolate and characterize bacteria from two crude oil-contaminated soils which were capable of producing biosurfactant and degrade oil. The contaminated soils were located in Tehran and Isfahan oil refineries, Iran. Various traits, such as hemolytic activity, oil resolving , oil spreading, and oil emulsifying capability were used to screen the isolates. Among 54 isolated isolates from two petroleum-contaminated soils, only 10 isolates were able to produce biosurfactant and degrade oil. These 10 isolates could produce glycolipid biosurfactants, which ranged from 1.93 to 3.7 g L−1. The results showed that four isolates (T4, T27, T30 and E1) could efficiently degrade crude oil in saline mineral broth, with the highest removal efficiency of 39% for T4. Gas chromatography analysis revealed that both lighter and heavier petroleum hydrocarbons were affected by microbial degradation. It was also demonstrated that branched alkanes as well as linear alkanes were degraded by the isolates. Based on 16S rDNA sequencing, all four isolates were identified as pseudomonas aeruginosa. Overall, this study shows that the biosurfactant production is a critical trait in screening of oil-degrading bacteria. Thus, the superior strains in this study are recommended for bioremediation programs, particularly in reclamation of crude oil-contaminated saline soils.

Aid dependence in Cambodia: How foreign assistance undermines democracy By SOPHAL EAR New York: Columbia University Press, 2013. Pp. 185. Figures, Tables, Notes, Bibliography, Index. The Cardamom conundrum: Reconciling development and conservation in the Kingdom of Cambodia By TIMOTHY J. KILLEEN Singapore: NUS Press, 2012. Pp. 354. Maps, Figures, Tables, Photographs, Notes, Index, doi: 10.1017/S0022463414000423 These volumes offer two very different, but complementary, perspectives on contemporary development questions in Cambodia. Both argue that they address the core issues that are shaping not only development in Cambodia but around the world and both offer insights which the authors hope will affect development pathways for the best. For Timothy Killeen the most pressing issue is how nations like Cambodia balance the need for economic development and wealth generation with the preservation of biodiversity and precious natural resources. For Sophal Ear the issue is that of aid dependence and the way that such dependence works to cripple national economies and stunt not only economic growth, but also social and political change towards a more equitable society. Read in tandem these two books provide valuable insights into what is happening in Cambodia and offer worthwhile advice to development agencies, donors, and governments about how best to shape their engagements. To begin with The Cardamom conundrum by Timothy Killeen. Killeen frames his book around a bit of a straw man, i.e. the 'conundrum' of the title in which Cambodia is faced with making a choice between economic development based on resource exploitation versus a 'green' choice of conserving the biodiversity and natural habitats of the Cardamom Mountains. As he argues from the beginning, the perceived tradeoffs are a false dichotomy. Killeen's argument is that the construction of a modern economy relies on sustainable exploitation of renewable natural resources, alongside wise investment of revenues from non-renewable resources. In the introduction Killeen offers the reader a vision of the future through three different scenarios: 'business as usual', a 'utilitarian' scenario in which some concessions are made to sustainability but economic growth is the driving concern, and a 'utopian' scenario which sees the creation of an economy based on green energy and limited exploitation of nonrenewable resources. Killeen's take-home point is that a 'green development pathway' is possible, if only Cambodia can make wise decisions around five key investment strategies: renewable energy, forest conservation, sustainable fisheries, agricultural intensification and a diversified tourist industry. The remainder of the book promises to show the reader how and why this is not only possible but necessary. Reading this introduction, however, I felt I was reading about a Cambodia that was not familiar to me: a 'Cambodia' that can be spoken of as if it had its own agency and is an entity that can take advantage of the 'opportunity' to 'choose an innovative development trajectory'; a Cambodia where the future is predictable, where shaping development is simply a matter of getting the right policies in place. Recognition of the immensely complex political and social realities of life in Cambodia seems absent here, and it is an omission that is only partially rectified in the body of the book. If social and political realities are brushed over, however, the volume certainly succeeds in providing a much deeper vision into Cambodia's natural resources and the potential for better resource management. In chapter 2 'Natural landscapes' Killeen is on stronger ground as he begins to build the factual data upon which his argument is based. In this chapter he offers a comprehensive and detailed discussion of Cambodia's natural resources. Likewise in chapter 3 'Human landscapes' and chapter 4 'Institutional landscapes', he is building a picture of human and institutional resources through which future development can take place. …

Habitat loss is widely regarded as one of the most destructive factors threatening native biodiversity. Because migratory waterbirds include some of the most globally endangered species, information on their sensitivity to landscape would benefit their conservation. While citizen science data on waterbird species occurrence are subjected to various biases, their appropriate interpretation can provide information of benefit to species conservation. We apply a bootstrapping procedure to citizen science data to reduce sampling biases and report the relative sensitivity of waterbird species to natural versus human‐dominated landscapes. Analyses are performed on 30,491 data records for 69 waterbird species referred to five functional groups observed in China between 2000 and 2018. Of these taxa, 30 species (43.5%) are significantly associated with natural landscapes, more so for cranes, geese, and ducks than for shorebirds and herons. The relationship between land association and the threat status of waterbirds is significant when the range size of species is considered as the mediator, and the higher the land association, the higher the threat status. Sensitive species significantly associated with natural landscapes are eight times more likely to be classified as National Protected Species (NPS) Classes I or II than less sensitive species significantly associated with human‐dominated landscapes. We demonstrate the potential for citizen science data to assist in conservation planning in the context of landscape changes. Our methods might assist others to obtain information to help relieve species decline and extinction.

Introduction: Heavy metals are types of elements naturally present in soil or enter into soil as a result of human activities. The most important route of exposure to heavy metals is daily intake of food. Crops grown in contaminated soil (due to mining activities, industrial operations and agriculture) may contain high concentrations of heavy metals. Also closeness to cities and industrial centers can have a great influence on the accumulation of heavy metals to agricultural products grown in the region. The study aimed to determine the concentration of heavy metals in soil and agricultural products around urban and industrial areas of Zanjan province (North West of Iran) and consumption hazard probability. Materials and Methods: Soil (75 samples of soil from a depth of 0 to 10 cm) and plant (101 samples) samples, in the summer 2011, were randomly taken from industrial areas as follow: tomatoes (Lycopersicum esculentum M), wheat seed (Triticum vulgare), barley seeds (Hordeum vulgare), alfalfa shoots (Medicago sativa L.), potato tubers (Solanumtuberosum L.), apple fruit, vegetables and fruits such as Dill (Aniethum graveolens L.), leek (Allium porrum L.), Gardencress (Barbara verna L.) and basil (Ocimum basilicum L.). Plant samples were then washed with distilled water, oven dried for48 hours at a temperature of 70 ´C until constant weight was attained and then they digested using 2 M hydrochloric acid (HCl) and nitric acid digestion in 5 M. Concentrations of heavy metals in the soil and crops were determined by atomic absorption spectrometry. DTPA extraction of metals by Lindsay and Norvell (1978) method and sequential extraction method by Tessier et al. (1979) were performed. Statistical analysis was accomplished using the software SPSS 16.0 and the comparison of mean values was done using the Duncan test at the 5% level of significance. Results and Discussion: The magnitude of variations for total copper was from 11.5 to 352.5 (average 52.4), zinc was from 96.3 to 1353.8 (average 264.8), lead was between 40.0 and 470.0 (average 105.7), nickel ranged from 12.8 to 77.0 (average 46.7) and chromium varied from 10.0 to 49.5 (average 21.7) mg kg-1. DTPA extracted heavy metals for copper varied from 1.50 to 21.23, averaging 4.47, zinc from 0.57 to 76.50 averaging 23.15, lead from 2.43 to 63.38 averaging 16.81 and nickel from 0.28 to 2.32 averaging 1.20 mg kg-1. Chemical changes in the different fractions were as follows: Cu (residual > bounded to organic matter > bounded to Fe-Mn oxides > bounded to carbonate > exchangeable fraction), Zn and Ni (residual > bounded to Fe-Mn oxides > bounded to carbonate > bounded to organic matter > exchangeable fraction,) and Pb (residual > bounded to Fe-Mn oxides > bounded to organic matter > bounded to carbonate > exchangeable fraction). The concentration of heavy metals in plant parts were high with respect to studied location. The highest amounts of Zn (Gardencress), Pb (Dill), Cu (Leek), Ni (Basil) and Cr (Basil), respectively were found to be 150.25, 41.25, 23.13, 6.46 and 3.47 mg kg-1 and the minimum amounts of the metals studied were found in fruits, wheat and barley grains. The total amount of metals in plants were as follow (Zn >> Pb > Cu > Ni > Cr). Bioaccumulation factor (BAF) of metals in plants were as Zn=Cu > Pb >> Cr > Ni. Hazard probability (HQ) in cancerous diseases for each element (except Pb) in both children and adults was less than unit. HQ content of Pb was much higher than the unit and for children and adults 9.07 and 6.94, respectively showing high contribution of Pb contamination of crops that threatens the consumer health in that location. The total amount of risk (THQ) in children was higher than that in adults. Conclusions: The results obtained in this study indicate that an urgent attention is required for consumer products related to public health, especially vegetables grown in the studied regions. Toxic effects of heavy metals have many deleterious effects which are more pronounced over time. With conventional monitoring of food quality produced in farms and presented in markets, excessive accumulation of heavy metals entering in to the human food chain can be prevented. Also, we can change the risk potential of heavy metals in the region by growing vegetables which accumulate heavy metals. Keywords: Agriculture products, Biological risk, Heavy metals, Soil, Zanjan province

Asparagus decline: Autotoxicity and autotoxic compounds in asparagus rhizomes

The paper presents the comparative analysis of the Palanga city landscape change during the period between 2008 and 2019. For this analysis, the land fund statistics of the Republic of Lithuania, which had been grouped into a relatively natural and anthropogenic landscape, were used. Landscape change is graphically shown in the figures. Lithuanian and foreign scientific literature and legal acts were analyzed for the fulfillment of the work. The Palanga city landscape analysis of the current situation was done. During the analysis the Palanga city statistics were compared with the data of Klaipeda County and the Republic of Lithuania. Landscape structure maintenance is the subject important and relevant to this day, as the landscape shapes the country's culture and is the component of natural and cultural heritage contributing to the quality of life and it consolidates Lithuanian identity, uniqueness in Europe and the world. The topic is actual because it is necessary to analyze landscape change in Palanga in order to evaluate and preserve the components of natural landscape in Lithuanian resort. The analysis showed that during the analyzed period the Palanga city natural landscape area 46.34 ha or 1.39 percent. The increase of the natural landscape area was determined by the development of water bodies and wetland areas.

Human activities have triggered profound changes in natural landscapes, resulting in species loss and disruption of pivotal ecological interactions such as insect herbivory. This antagonistic interaction is affected by complex pathways (e.g., abundance of herbivores and predators, plant chemical defenses, and resource availability), but the knowledge regarding how forest loss and fragmentation affect insect herbivory in human-modified tropical landscapes still remains poorly understood. In this context, we assessed multi-pathways by which changes in landscape structure likely influence insect herbivory in 20 Atlantic forest fragments in Brazil. Using path analysis, we estimated the direct effects of forest cover and forest edge density, and the indirect effect via canopy openness, number of understory plants and phenolic compounds, on leaf damage in understory plants located in the edge and interior of forest fragments. In particular, plants located in forest edges experienced greater leaf damage than interior ones. We observed that landscape edge density exerted a positive and direct effect on leaf damage in plants sampled at the edge of forest fragments. Our findings also indicated that forest loss and increase of edge density led to an increase in the canopy opening in the forest interior, which causes a reduction in the number of understory plants and, consequently, an increase in leaf damage. In addition, we detected that phenolic compounds negatively influence leaf damage in forest interior plants. Given the increasing forest loss in tropical regions, in which forest fragments become stranded in highly deforested, edge-dominated and degraded landscapes, our study highlights the pervasive enhancement in insect herbivory in remaining forest fragments-especially along forest edges and canopy gaps in the forest interior. As a result, increased herbivory is likely to affect forest regeneration and accelerate the ecological meltdown processes in these highly deforested and disturbed anthropogenic landscapes.

The effect of pollution of Albicluvisols/Retisols, Calcaric Leptosols, Luvic Phaeozems, Greyzamic Phaeozems and Folic Fluvisols with oil (Solovatovsky oil field, Perm region) added in amounts of 1, 2, 3 and 5g oil/kg of soil on the organisms was studied in a model laboratory experiment. Oil addition showed phytotoxic effects on root length in Triticum aestivum L., Lepidium sativum L., Picea obovata Ledeb. and Pinus sylvestris L. in all soils. However, oil contamination of Calcaric Leptosols and Greyzamic Phaeozems led to growth stimulation in Picea obovata seedlings. A remarkable shift in the diversity and number of colony-forming units of heterotrophic and oil-oxidizing bacteria was detected in all soil types. The maximum decrease in biodiversity (45%) was noted for heterotrophic bacteria in Luvic Phaeozems. Aqueous extracts from all oil-contaminated soils had a toxic effect on Chlorella vulgaris Beijer, causing an increase in biomass by more than 30%, but did not show acute toxicity on Daphnia magna Straus. Oil addition in the range of 1-3g oil/kg soil posed no environmental risk to human health. However, oil addition at 5g oil/kg of soil led to an increase in the level of carcinogenic risk to children to the threshold values of acceptable risk and ranged from 0.95 × 10-4 for Greyzamic Phaeozems and Folic Fluvisols to 1.098 × 10-4 for Luvic Phaeozems. Our results suggest that the reaction of test organisms to oil pollution depends on the soil type, and their complex application makes it possible to identify the most sensitive factor and assess the dangerous level of pollution.

Recultivation of oil-contaminated soils on the Absheron Peninsula is one of the most important environmental and social problems for this region. One of the promising ways to solve the problem of soil pollution with petroleum hydrocarbons is the development of methods and approaches for their purification and detoxification in situ, and above all, biodetoxification and bioremediation. In a model vegetation experiment using complex systems of a mixture of plants and microorganisms, phytoremediation of soil contaminated with crude oil at a concentration of 15 g/kg was investigated. It has been established that the inoculation of plants with the modified Fermi-Start biological product affects the number of rhizosphere microorganisms that stimulate plant growth, as well as the degree of purification of gray-brown soil from oil. Cynodon dactylon is an effective biosystem for the remediation of oil-contaminated gray-brown soils as it is modified by a culture of an oil-oxidizing microorganism of the Pseudomonas aeruginosa, isolated from oil-contaminated gray-brown soil, the Fermi-Start biological product and belongs to the group of “effective microorganisms”, associated with plants — Medicago sativa. The joint introduction of the Fermi-Start biological product and the culture of P. aeruginosa had the greatest protective effect on seedlings from exposure to crude oil. The height of the shoots increased by 71% compared with the negative control, in parallel, the degree of oil degradation increased to 24%. A significant role of alfalfa in stimulating the number of rhizosphere microorganisms capable of hydrocarbon degradation has been revealed. This is confirmed by data showing that the number of microorganisms in the plant rhizoplane was 1–2 orders of magnitude higher (about 1.1×107 on average) than in the rhizosphere (about 1.4×105 on average), which may be due to secretion of plant root exudates. The results of the research allow us to recommend the use of a plant-microbial biosystem consisting of Medicago sativa and Cynodon dactylon, together with a Fermi-Start modified biological product for phytoremediation of gray-brown soil contaminated with crude oil.