The paper presents results of an investigation into the impact of microplastics, specifically spherical polystyrene particles with an average diameter of 160 nm, on urban soils of various origins. These microplastics are represented by microplastic. The study focused on the topsoil layers of parks and courtyards in Moscow, including Urban Technosols and Technosols with humic and transport characteristics. Additionally, samples from Maikop were analyzed, including Fluvic Phaeozems and Ekranic Technosols. Sand and sand-peat models were also used in the study. The concentration of microplastics in the samples was kept at 1
Hydromorphic soils play a key role in the terrestrial carbon cycle, regulating the water cycle, and sustaining various ecosystem services; therefore, they are of major importance to the functioning of terrestrial ecosystems. The importance of investigating hydromorphic soils has become increasingly pronounced as climate change, rising temperatures, decreasing precipitation and groundwater levels, and the progressive loss of wetlands contribute to the reduction in the spatial extent of these soils. However, their classification can be challenging, as hydromorphic morphological features, such as gley patterns, are not always readily distinguishable, and their interpretation may depend to some extent on the expertise and judgment of the soil surveyor. Diffuse reflectance spectroscopy offers a fast, cost-effective, and environment-friendly alternative in the visible (VIS), near-infrared (NIR), and mid-infrared (MIR) ranges for the simultaneous determination of the physical, chemical, and mineralogical properties of soil. The spectral behavior of hydromorphic soils is primarily determined by changes in soil moisture, the accumulation of organic matter, and the oxidation and reduction processes of iron, which result in characteristic spectral signatures. These spectral characteristics carry integrated information about soil formation processes and can contribute to a more objective identification of water-saturated soils. This study aims to review the spectral characteristics of hydromorphic soils and to present how VIS–NIR and MIR reflectance spectroscopy can be applied to support the identification and classification of hydromorphic soils.
Urban soils accumulate toxic elements from vehicle exhaust, industrial emissions, and household waste. The increasing number of vehicles with catalytic converters has led to the accumulation of platinum group elements and other heavy metals in roadside soils, which negatively affects the biological properties of soils and public health. The degree of polymetallic contamination of roadside soils in the Vasileostrovsky district of St. Petersburg was studied. Twenty samples were taken from the surface (0–5 cm) horizon of soils in roadside areas at a distance of no more than 1 m from the highways, The studied soils are characterized by the coarse texture (sand, loamy sand), slightly alkaline to alkaline reaction (pH 7.9 ± 0.5), moderate content of Corg (3.60 ± 1.02
A scientific substantiation of approaches to environmental regulation of the permissible impact of waste disposal facilities (using the hydraulic-fill tailings of the Festival’noe tin ore deposit in Khabarovsk region as an example) on the soil cover of adjacent areas mainly represented by podzols, was conducted. The regulation consists of establishing a level of pollutant input into the soil that preserves the soil’s ability to perform ecological functions. The study confirms that concentric zones (quality categories) with varying degrees of soil degradation are formed around the anthropogenic object. These zones are identified by analyzing changes in biological indicators (soil respiration rate, soil microbial biomass, and vegetation index) as response to increasing soil contamination with copper, arsenic, and sulfur. Biological response intervals and corresponding concentrations are calculated using a uniform schedule of the condition indicator. The first quality category corresponds to the conventional background. In the second category, the level of soil bioorganic potential decreases to 30
To enhance the effectiveness of ecological functions performed by urban soils in the Central Chernozem Region of Russia, a comprehensive ecosystem approach to their assessment and management is proposed, taking into account region-specific typological features of soil genesis, functioning, and regimes of anthropogenic use. The study was conducted in the cities of Kursk and Lgov, as well as in the Zheleznogorsk and Gubkin urban agglomerations in the Kursk and Belgorod oblasts. We assessed the ecological status, degree of degradation and contamination of soils (integrated contamination index Zc up to 101.6), protective and regulatory functions (assessed via capacity and contrast of soil geochemical barriers), heavy metals vertical migration rates in the soil profile, the status of plants, fungi, and soil microbiota, and the level of anthropogenic impact. High spatial variability of key soil properties was established (Corg 0.4–8.9
The paper presents the results of a model experiment in the humus horizon of soddy-podzolic sandy loamy soil (Albic Retisol), which was saturated with sewage sludge until 1990. As a result, complex multi-element contamination with heavy metals has been formed, which persisted even after 30 years. The aim of this work is to study the possibility of remediating soils contaminated with sewage sludge using chemical and biological rehabilitation methods. A total content of heavy metals was determined after soil treatment with concentrated HCl + HNO3 acids in a ratio of 3 : 1, and the content of mobile compounds was analyzed in the CH3COONH4 extract with a pH of 4.8. The concentration of heavy metals was measured on an Agilent 5110 optical emission spectrometer using the ICP-OES method. The use of organic and mineral remediants, i.e., zeolite clinoptilolite, zeolite ZION, humic preparation Vibrostend, biochar, and compost, proved the possibility to reduce the heavy metal content in vetch (Vicia sp.) and flax (Linum sp.) plants and to increase their biomass by 20–30
Pesticide residues were determined in soil and water in several regions (Tula oblast, Krasnodar region, and Uzbekistan). Components of modern pesticides were not detected, but trace concentrations of obsolete organochlorine pesticides were found. The non-obvious patterns of concentration of these residues in soil and water sources indicate their long-term migration potential and the existence of active pathways for their removal into the groundwater zone. A study of transport pathways in soil pore space was conducted using Haplic Chernozem in the Tula oblast as an example. A laboratory lysimetric experiment was conducted with a soil monolith from the upper part of the profile, and scenario-based migration calculations were performed using the PEARL model. The lysimetric experiment revealed extremely uneven flow and removal of the nonsorbable KBr tracer and the pesticide imazamox (Koc = 11 L/kg, DT50 = 200 days) along the base of the monolith. More than 80
The article presents an analytical review of methodological approaches to the allocation of reference soil plots on land for various purposes. The scientific concepts of reference, background, control and reference state of soils used in soil science, agroecology, environmental regulation, pollution monitoring and land degradation assessment are considered. Based on the analysis of domestic and foreign publications, it is shown that the choice of a reference site is determined not only by the degree of soil cover preservation, but also by the category of land, the nature of anthropogenic impact, the objectives of the study and the required level of evidence for conclusions. The main approaches to soil standardization are systematized, including natural genetic, agroecological, background monitoring, expert legal, and restoration and reclamation. The methodological options and limitations of using reference plots in agricultural, forest, urbanized, specially protected and disturbed territories are analyzed. It is shown that the comparative approach is widely used in modern research, however, the criteria of spatial comparability, representativeness and functional adequacy of reference sites remain different. The necessity of a transition from an intuitive choice of background and control sites to a more unified system of choosing soil standards considering genetic, landscape, functional, analytical and legal criteria is substantiated. It is concluded that the reference site should be considered as a special tool for comparative assessment of soil condition, applied differentially depending on the objectives of monitoring, rationing, damage assessment, and land restoration.
The aim of this study is to conduct a comprehensive assessment of soils in the Vasileostrovskii District of Saint Petersburg. The following parameters have been determined in 16 samples of Urbic Technosol taken from four functional zones (transport (TZ), park-recreational (PRZ), industrial (IZ), and residential (RZ) ones): the content of mobile forms of heavy metals (Cd, Cu, Pb, Ni, and Zn), the total content of petroleum hydrocarbons, agrochemical properties (pH, available P, available K, total C, and total N), phytotoxicity (using Avena sativa as a test object), and parameters of microbiological activity (basal respiration, microbial biomass, metabolic quotient qCO2, and microbial quotient QR). The Cu and Pb content in most samples exceeds their maximal permissible concentrations (MPC). The petroleum hydrocarbon content at two sampling sites (2 and 4) exceeds the approximate permissible concentration (APC) by a factor of 1.1–1.4. The assessment of the biological status of soils has revealed a strong inhibition in microbiological activity and a stressed status of microbial communities. A reduction in seed germination (to 51
This study evaluated partial substitution of synthetic fertilizers with organic amendments on heavy metal migration and health risks in a soil–tea system. A one-year field experiment tested 30 and 50
This study assessed the fractionation and ecological risk of heavy metals (Ni, Cr, Cd, Pb, Zn, Cu, Fe, and Mn) using twenty surface soil samples collected from major industrial zones, Coimbatore, Tamil Nadu, India. The soils, classified as Technosols, Anthrosols,Luvisols and Acrisols (WRB), exhibited clay loam texture, neutral to Alkaline pH (6.30–8.08), low to moderate organic carbon (0.02–0.75
Natural farming (NF), which leverages local ecological resources and indigenous livestock, has emerged as a potential alternative to mitigate soil degradation and ecological damage caused by intensified conventional farming (CF) under population pressure and excessive agrochemical use in the Indian Himalayas. To assess the effects of NF and CF systems on soil properties and quality, an investigation was conducted, collecting 300 soil samples (150 from each system), across six blocks in Hamirpur district, Himachal Pradesh. Samples were analysed for soil physical, chemical, and biological properties, as well as the soil quality index was computed using principal component analysis (PCA). Texturally, soils from both farming systems were classified as sandy loam to loamy sand. However, NF exhibited lower bulk density, higher porosity, and a greater maximum water-holding capacity than CF. Soil organic carbon levels were categorised as medium to high in NF, whereas they ranged from low to high in CF. Additionally, bioavailable macronutrients (N, P, K, S) and DTPA-extractable micronutrients were higher in NF. Furthermore, biological activities were generally higher in NF, except for urease activity. PCA identified five soil quality indicators for NF and six for CF, accounting for 84.7 and 89.1
Pedogenic characterization and classification are fundamental for sustainable land use planning in fragile dryland ecosystems. Understanding the vertical distribution of inherent soil properties is essential for evaluating their suitability and management requirements. This study was conducted to characterize, classify and assess the fertility status of representative dryland soils of southern Haryana, India as controlled by prevalent climate and geomorphology. Five pedons representing aeolian sand dunes and fluvio-aeolian plains were studied through standard field description and laboratory analyses, and classified under WRB for Soil Resources and USDA Soil Taxonomy guidelines. Morphological observations revealed clear contrasts among landforms: Dune pedons (1 and 2) exhibited simple A–C profiles, sandy texture, and weak structure, indicating minimal pedogenesis, whereas pedons from fluvio-aeolian plain (3–5) showed A–B–C profiles with subangular blocky structure and carbonate accumulation, reflecting early horizon development. Physico-chemical properties indicated alkaline reaction (pH 7.31–8.87), mostly non-saline conditions (EC 0.15–0.52 dS m–1, except higher values in Pedon 5), low organic carbon (0.07–0.57
Historical and contemporary aspects of the rulemaking and practical organization of the system of environmental regulation of soils and lands in the Russian Federation are considered. The current situation is characterized by the absence of unified approaches to environmental quality regulation. The lack of established environmental standards is particularly acute for soils and lands as independent components of the natural environment. Soils and lands are the most complex natural systems in terms of spatial heterogeneity of the soil cover, and lands are also subject to the peculiarities of administrative division of territories and the organization of economic activity. This complicates the resolution of issues related to the environmental ranking of soils and lands, as well as methods for determining the values of permissible deviations from background levels of observed parameters. In particular, this article considers the development of ranking scales for qualitative and quantitative indicators characterizing changes in their condition under the influence of natural and anthropogenic factors. Regulatory documents in the field of soil and land protection are analyzed with a view to their further improvement in establishing baseline soil and land parameters and permissible deviations from them without disturbing their ability to perform ecological functions. These documents are based on scientific understanding of the resilience and self-remediation properties of the natural environment, soils, and lands under diverse environmental management practices and associated levels of degradation. The introduction of modern methods, particularly those based on the Gendugov–Glazunov model, can improve the current state of environmental assessment and regulation of soils and lands. These methods also enable the practical implementation of the approaches outlined in the Ecomonitoring Federal State Information System (FSIS) and the Regulation on the Development, Establishment, and Revision of Environmental Quality Standards (no. 149). The article lists the scientific and practical works and regulatory documents that served as the foundation for the development of a system for environmental regulation of soils and lands contaminated with petroleum products and other pollutants. It is noted that further scientific and practical development of environmental regulation serves as a system-forming basis for environmental monitoring and the closely related regulation of the natural and resource potential of soils and lands, as well as the maintenance of favorable socio-economic and environmental living conditions for the population of Russia’s regions.
Olive millwastewater (OMW), a by-product of olive oil production, is known for its high concentrations of organic matter, phenolic compounds, and nutrients, which can pose environmental risks if released untreated. However, OMW can also serve as a potential soil amendment under controlled application. This study investigated the long-term effects of repeated OMW applications on the physicochemical properties and humification of soil organic matter in a Mediterranean arid soil (Eutric Regosol). Soils were sampled at two depths (0–20 and 20–40 cm) in experimental plots receiving different OMW doses over nine years. Soil chemical parameters, including pH, electrical conductivity, cation exchange capacity and nutrient contents, were analyzed. Humic substances were extracted and characterized using spectroscopic techniques, including UV–Visible (E4/E6 ratio) and Fourier-transform infrared (FTIR) spectroscopy, to assess molecular changes and humification dynamics. Results revealed that OMW application enhanced soil organic matter content, improved nutrient availability, and increased cation exchange capacity, particularly in surface layers. Phenolic compounds accumulated mainly in the topsoil, while humification indices (HA/FA ratio) indicated an increased degree of soil organic matter stabilization under higher OMW doses. UV–Visible and FTIR analyses confirmed enhanced condensation of aromatic structures and incorporation of nitrogen- and carboxyl-containing compounds in soils receiving OMW. These findings demonstrate that long-term OMW applications can promote the formation of stable humic substances, improving soil quality and fertility in arid Mediterranean environments.
Soil fertility decline during grassland degradation is reflected not only by nutrient depletion but also by changes in microbial biomass and enzyme-mediated processes that regulate nutrient cycling. However, whether degradation-driven vegetation replacement leads to recovery or further decline of soil fertility in subalpine meadow soils remains insufficiently understood. The purpose of this study was to determine how soil nutrient pools, microbial biomass, and enzyme activities change along a vegetation replacement gradient and to identify the soil physicochemical factors associated with these changes. A space-for-time substitution approach was used to compare native meadow soil with soils from three successive expansion stages of Stellera chamaejasme L. Soil physicochemical properties, total and available nutrient pools, microbial biomass, and the activities of urease and catalase were determined. Differences among stages were evaluated using one-way ANOVA, and relationships among variables were analyzed using Pearson correlation analysis. With increasing vegetation replacement, soil pH and soil water content increased significantly, whereas soil organic carbon, total nitrogen, total phosphorus, available nitrogen, and available phosphorus declined overall. By contrast, potassium-related fractions showed a tendency toward relative accumulation. Soil microbial biomass and enzyme activities decreased markedly along the gradient, with microbial biomass carbon declining from 725.6 to 312.4 mg kg–1 and urease activity from 1.82 to 0.75 mg g–1 d–1. Correlation analysis showed that soil pH was negatively associated with most C-, N-, and P-related nutrient variables, microbial biomass, and enzyme activities, suggesting that changes in soil chemical conditions were closely linked to reduced biochemical functioning. These results indicate that degradation-driven vegetation replacement in subalpine meadows is accompanied primarily by depletion of C, N, and P nutrient pools and suppression of enzyme-mediated processes, despite partial accumulation of potassium fractions. The combined responses of soil nutrients, microbial biomass, and enzyme activities can serve as useful indicators for diagnosing soil fertility decline and functional degradation of meadow soils.
Vehicle-related pollutants can have a significant impact on both human health and the ecosystem. Current study was conducted to investigate the heavy metals lead (Pb), cadmium (Cd) and copper (Cu) concentration in the soil along the roads: National Highway > Provincial Highway > Northern Bypass. Soil samples were collected from different locations of Bahawalpur city. Then samples were analyzed to measure the pH, EC1 : 1 and heavy metals (Cd, Cu and Pb) concentrations and pollution level in upper layer of soil with 15 cm depth. Based on results of study, heavy metal concentrations in soil followed the order Pb > Cu > Cd and total Pb concentration range (157–600 mg kg–1) > Cd range (2.4 to 9 mg kg–1) > Cu range (7 to 35 mg kg–1) based on distinct geographic locations (N > P > B). To gauge the amount of heavy metal contamination in soil, the pollution indices (CF Igeo) were utilized. According to the CF and Igeo values, order of the metal is Cu < Pb < Cd and its ranges from uncontaminated to heavily contaminated depending on traffic intensity.
This study evaluates soil quality and its influence on rice yield in paddy fields by integrating soil properties and terrain attributes within a multivariate framework. The objective of this study was to provide a methodological template for coupling soil quality indicators with topographic context to support site-specific nutrient management in coastal and upland rice systems. In this study, 80 topsoil samples (0–30 cm) were collected from areas ranging from lower coastal to higher elevations. A total of 21 soil properties relevant to rice cultivation were determined. We established three groups of minimum data sets (MDS): (1) using all soil indicators (MDS1), (2) considering physical, chemical, and biological indicators separately (MDS2), and (3) calculating the norm values for soil indicators alongside five terrain attributes derived from a digital elevation model (DEM), including elevation, slope, topographic wetness index (TWI), stream power index (SPI), flow direction (FD), the nearest straight-line distance from the sampling point to the river (Dr), and the nearest straight-line distance from the sampling point to the coastline (Ds) (MDS3). Soil quality was evaluated using the integrated quality index (IQI) and the Nemerov quality index (NQI). The analysis indicated that IQI-MDS1 and IQI-MDS3 had the highest priority based on the sensitivity index (SI(, and efficiency ratio (ER), while NQI-MDS2 was assigned the lowest priority. Notably, IQI-MDS3 and NQI-MDS2 explained 71 and 48
Available iron (Fe) deficiency is prevalent issue in the Indo-Gangetic plain particularly in the areas with higher pH levels, lower organic carbon content and high concentration of calcium carbonate in the soil causing significant impact on agriculture production. To improve Fe availability, it is necessary to comprehend the relationship between Fe fractions in soil, its availability and their responses to different cropping systems: rice-wheat (RW) and legume-wheat (LW). Surface soil samples (0–15 cm) were collected from agriculture fields with different cropping systems rice-wheat and legume-wheat of Indo-Gangetic plain and were analysed for different soil iron fractions in the laboratory by the Tessier method. Soil properties such as pH, organic carbon, electrical conductivity, nitrogen, phosphorus, and potassium and CaCO3 were also measured. The mean Fe fractions in soil samples were found in the following order: Residual Fe > Manganese oxide-bound > Organic bound Fe (Org–Fe) > Carbonate bound Fe > Exchangeable Fe (Ex–Fe). LW cropping system significantly restores Ex–Fe and Org–Fe by 11.5 and 55
Wildfire is a major disturbance that affects soil properties and nutrient dynamics in cold-temperate coniferous forest ecosystems. Pyrogenic nitrogen (PyN) consists of nitrogen-containing pyrogenic compounds formed and accumulated during the incomplete combustion of biomass. Due to its high environmental stability, PyN is widely distributed in soils and sediments. We established four plots at different slope positions (upper slope, middle slope, lower slope, and valley) in a cold-temperate coniferous forest that experienced a severe wildfire in 2010. At each plot, soil samples were collected from three depth intervals (0–10, 10–20, and 20–30 cm). The samples were then separated into four particle size fractions for the analysis of PyN content and density. Thirteen years after the fire, soil PyN content and density ranged from 0.20 to 0.32 g kg–1 and 0.18 to 0.47 t ha–1, respectively. PyN content and density in the upper-slope soils were markedly lower than those at the other slope positions, accounting for only 6.70 and 1.25
