Horizon Depth Research Articles

Evaluation of the soil quality using health index in temperate European conditions (Slovak Republic)

Land users and policy makers recognize importance of soil health and these types of evaluations are welcomed within sustainable land management. The aim of this study was to establish minimum and maximum values of soil health index across the breadth of agricultural used soils of Slovakia. Core objectives included (1) identifying the range of soil health benchmarks; (2) defining benchmarks for different land uses, and (3) defining benchmarks of soil health index for main groups of agricultural soils in Slovakia. These benchmarks represent the first soil health metrics of their kind in Slovakia using data from 266 locations. The soil health index (SHI) approach has been used as a quantitative tool to establish linkage between soil health and soil ecosystem services. We recorded the highest average SHI value in the very warm climatic region of the Slovak Republic, where the majority of agriculturally used arable soils (with an optimal pH value without contamination) are located. The locality with lowest SHI value is in a slightly warm area on soil used as arable soil with a very small depth of humus horizon, with by the pH value in an acidic area, and with a high content of clay. The typical SHI in humus-rich soil groups of Slovakia (Mollic Fluvisols, Chernozems and Cutanhic Luvisols) is higher contrasted with the typical SHI in other soil groups of Slovakia.

Biogeochemical cycling of trace elements and nutrients in ferruginous waters: Constraints from a deep oligotrophic ancient lake

AbstractIron‐rich, ferruginous waters were the dominant geochemical regime for most of Earth's history. Modern ferruginous waters are found in stratified, sulfur‐poor lakes, and serve as crucial analogs for biogeochemical cycling throughout Earth's past. Here we present the first depth‐resolved data of physical structure, nutrients and trace elements from Lake Poso (Indonesia), a deep oligotrophic ancient lake. Lake Poso is ferruginous, with anoxia below ~ 90 m depth, placing it among the world's largest ferruginous lakes. Physical stratification is weaker than other tropical anoxic lakes, indicating sensitivity for paleoclimate reconstructions. Trace elements and nutrients are predominantly shaped by the oxic–anoxic transition. Manganese– and Fe oxyhydroxide–driven biogeochemical cycling occurs at distinct depth horizons, with Co and Ni controlled by Mn and showing shallow release in anoxic waters, while V, Cr, P, and As are controlled by Fe, with release in surface sediments and diffusive transport. Chromium is nonquantitatively removed in anoxic waters, in contrast to widespread assumptions in Cr‐based paleoreconstructions. Oxycline U and Se removal corresponds to a local N minimum, suggesting biological reduction and/or uptake. These first ferruginous water Se data also show removal in sediments, indicating sediment signals reflect multiple removal processes and informing Se‐based paleoreconstructions, while the absence of sediment U removal contrasts other anoxic basins. A comparison with other ferruginous lakes demonstrates how local influences drive deviations from expectations in other systems, and highlight common, generalizable ferruginous basin features. Therefore, these data will guide research in ferruginous settings across space and time, and improve paleoreconstructions from ferruginous sediment records.

Changes in the physical properties of fallow lands during their regeneration

The change of physical and mechanical properties of soil depending on the methods of its cultivation has been studied. The experiments were carried out in the Novosibirsk region from April to September 2023. To study the structure of the soil, a soil section was made to a depth of 0.7 meters. It was determined that the soil at the experiment plots was gray forest, the thickness of the turf layer was on average 10 cm, the depth of the humus horizon 25–27 cm, a layer of sandy loam was observed under the humus layer. Fallow land cultivation was carried out by the tillage combine AKP-2.5N with MTР-80L tractor and the working width of 1.8 meters. The working body of the AKP-2.5N was made in a form of a straight rack with a blade measuring 410 mm, in addition, a small screen was installed on the rack. The unit provides for the installation of the rollers with a size of 600 mm. To determine the operating modes of the unit, studies were carried out in the soil channel. It was found that the operating speed of the unit with installed screen should be no more than 2.22 m/s or 8 km/h. The conditions of the experiment: gray forest soil, air temperature not lower than 10 0C; air humidity no more than 70%; relative humidity of at least 18%, wind speed not higher than 2 m/s; the average length of the rut is not less than 70 m and without stones on the field. It has been concluded that the most rational way to introduce fallow gray forest soils into agricultural circulation is to treat them with AKP-2.5N units with working bodies equipped with blades. After three treatments, the content of soil particles less than 10 mm is up to 93.1%, the soil absorbs moisture faster and reduces the hardness to 15 kg/cm2, which corresponds to the hardness of the soil of the field in rotation. Equations of regularity of changes in the fractional composition of soil with a size of less than 10 mm and more than 50 mm depending on the timing and number of treatments have been obtained.

Soil resilience assessment using soil profile descriptions and Analytic Hierarchy Process in Mediterranean mountains considering diverse fire occurrences

Wildfires are complex natural phenomena that exert significant impacts on landscapes, societies, and economies. Understanding the concept of resilience is crucial in mitigating its possible negative impacts, as it involves preparing for, responding to, and recovering from wildfires. This research aims to demonstrate the utility of in situ soil profile description in assessing land use resilience using an Analytic Hierarchy Process (AHP) through an expert panel survey. The study examines a catchment located in the Balearic Islands, considering two fire occurrences (once and twice), comparing abandoned agricultural terraces and natural hillslopes. The results demonstrated that the priority ranking of variables to assess soil profile resilience against wildfires, determined by a panel of 10 experts, identified horizon depth (25.1%), slope inclination (21.5%), and hydrological connectivity (16.6%) as the most crucial factors. Other variables, such as number and size of roots, structure of pedal soil material, size class structure, and rock fragments, also contributed to resilience but to a lesser extent, with scores ranging from 5.7% to 9.6%. Analyzing the priorities established by the experts using AHP, the results showed that the least resilient soil horizon was H1 of the control hillslope, especially under high and low connectivity processes, which aligned with the loss of superficial soil horizons after one and two wildfires. Hillslopes showed greater changes in resilience after occurring wildfires compared to terraces, with the most significant alterations occurring after the second wildfire event. This study addresses a significant knowledge gap in the field by highlighting the interconnectedness of wildfires, resilience, and land use, providing insights into land management strategies for wildfire-prone regions.

Primary to post-depositional microbial controls on the stable and clumped isotope record of shoreline sediments at Fayetteville Green Lake.

Lacustrine carbonates are a powerful archive of paleoenvironmental information but are susceptible to post-depositional alteration. Microbial metabolisms can drive such alteration by changing carbonate saturation insitu, thereby driving dissolution or precipitation. The net impact these microbial processes have on the primary δ18O, δ13C, and Δ47 values of lacustrine carbonate is not fully known. We studied the evolution of microbial community structure and the porewater and sediment geochemistry in the upper ~30 cm of sediment from two shoreline sites at Green Lake, Fayetteville, NY over 2 years of seasonal sampling. We linked seasonal and depth-based changes of porewater carbonate chemistry to microbial community composition, insitu carbon cycling (using δ13C values of carbonate, dissolved inorganic carbon (DIC), and organic matter), and dominant allochems and facies. We interpret that microbial processes are a dominant control on carbon cycling within the sediment, affecting porewater DIC, aqueous carbon chemistry, and carbonate carbon and clumped isotope geochemistry. Across all seasons and sites, microbial organic matter remineralization lowers the δ13C of the porewater DIC. Elevated carbonate saturation states in the sediment porewaters (Ω > 3) were attributed to microbes from groups capable of sulfate reduction, which were abundant in the sediment below 5 cm depth. The nearshore carbonate sediments at Green Lake are mainly composed of microbialite intraclasts/oncoids, charophytes, larger calcite crystals, and authigenic micrite-each with a different origin. Authigenic micrite is interpreted to have precipitated insitu from the supersaturated porewaters from microbial metabolism. The stable carbon isotope values (δ13Ccarb) and clumped isotope values (Δ47) of bulk carbonate sediments from the same depth horizons and site varied depending on both the sampling season and the specific location within a site, indicating localized (μm to mm) controls on carbon and clumped isotope values. Our results suggest that biological processes are a dominant control on carbon chemistry within the sedimentary subsurface of the shorelines of Green Lake, from actively forming microbialites to pore space organic matter remineralization and micrite authigenesis. A combination of biological activity, hydrologic balance, and allochem composition of the sediments set the stable carbon, oxygen, and clumped isotope signals preserved by the Green Lake carbonate sediments.

Carbon accumulation features in different functional zones of cities in the steppe zone.

This article presents findings on the study of content, profile distribution, and reserves of various carbon forms (organic carbon (TOC) and inorganic carbon (IC)) in Urbic Technosols and Ekranic Technosols within the residential zone of the city, alongside zonal Calcic Chernozems in the recreational zone of Rostov-on-Don, Aksai, and Bataysk. It was revealed that the TOC content in the upper horizons of Urbic Technosols is significantly lower than in the chernozem horizons of fallow areas, registering at 2.59 ± 0.79% and 3.25 ± 0.94%, respectively. IC exhibits an inverse trend, with maximum content observed in the upper horizons of Ekranic Technosols. Down the soil profile, disparities in TOC and IC contents are mitigated. This specificity in TOC accumulation and profile distribution signifies a "bipartite" profile alteration in buried chernozems, affecting solely the upper stratum rather than the entire soil profile. The presence of woody vegetation in the dry-steppe zone positively influences TOC accumulation. Calcic Chernozems beneath woody vegetation showcase the highest TOC reserves within the 30-cm layer (10.61 ± 1.45kg/m2). Calcic Chernozems of fallow areas under natural steppe vegetation contain 8.94 ± 1.75kg/m2, Technosols of the residential zone 8.44 ± 2.47kg/m2. For Technosols of the residential zone, a weakening of the dependence of TOC and IC content on the depth of the soil horizon is observed.

Analysis of the substances migration within the trophic chain “soil — plant — raw meat materials”

The trophic chain, which manifests the correlation at nutritional level between various macro- and microorganisms, is an important factor of the ecosystem; it can show the migration of various substances within the chain “soil — water — plant — animals”. The trophic chain in Borgoy depression area was studied due to the profound correlation between the compositional characteristics of the soil and pronounced organoleptic features of meat of the sheep that feed on grass in this area. For the experiments, control and experimental samples of soil, water, plants and mutton meat were examined. The samples taken near the saline lake within the Borgoy depression on the west of Beloozersk village served as an experimental sample. The samples taken 30 km from the salt lake near Petropavlovsk village in the Republic of Buryatia served as control sample. Experiments have shown that the soil of the Borgoy depression is a saline soil, with a depth of the salt horizon of 0–30 cm, and the salt belongs to chloride-sulfate-soda type of salinity. It is noted that the saline soil is characterized by a much higher content of carbonates, chlorides and cations of sodium, potassium and magnesium. Correlation was found between the isotopic composition in soil, vegetation and the raw meat materials. More profound certain organoleptic features of Borgoy mutton were noted. It’s highly probable that this fact is associated with the peculiarities of the mineral, chemical, and amino acid compositions of meat of the livestock that lives in the pastures of the Borgoy depression, characterized by saline soils. Despite the increased content of heavy metals such as lead and copper in the soil, data on sheep muscle tissue showed that all values of toxic elements content are within the permissible concentration range. The transfer of heavy metals from the soil to the aboveground part of plants is hindered by the underground root part, which serves as barrier.

Ecological Risk Assessment, Distribution and Source of Polycyclic Aromatic Hydrocarbons in the Soil of Urban and Suburban Forest Areas of Southern Poland

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that can pose a risk to people living near contaminated soils. The role of forest ecosystems around urban agglomerations as a draw to urban dwellers has been highlighted by the COVID-19 pandemic. The pandemic led us to focus this study on the soils beneath forested areas around urban agglomerations, with the aim of assessing the sources and ecological risk of PAHs in the soils. For the study, a 150 km transect was delineated by six sampling sites, located in urban and commercial forests, which were characterised by the same species composition. Samples were taken from the 0–10 cm depth horizon, after removal of the organic layer. The content of 16 PAHs was determined, from which the potential source of contamination, the toxic equivalent quotient (TEQ), the potential ecological risk quotient (RQ) and the incremental lifetime cancer risk quotient (ILCR) were calculated. The mean sums of the PAHs ranged from 12.41 to 52.76 μg·kg−1. Our analysis indicated that the share of pollutants in the soils had resulted from industrial combustion, biomass and coal combustion, and traffic. The RQ of the PAHs in the soils of the Upper Silesian Industrial Region, or within its impact range, were found to be low to moderate. High ILCR ratios for children (1.9 × 10−4) and adults (8.38 × 10−5) were recorded in soils related to a refinery. Our findings confirm that forests around urban areas are vulnerable to pollution. People living in cities should consider spending their leisure time in forest areas at a distance from their homes. Systematic and continuous monitoring of PAHs is necessary to ensure that human safety is guaranteed.

Organic carbon distribution between structural and process pools in the gray forest soil of different land use

The summarized data on the content of organic carbon (Corg) in the subtypes of gray forest soils occurring on the territory of Russia was presented. It was shown that the humus horizons of virgin light-gray, typical-gray, and dark-gray forest soils contain, on average, 2.16 ± 0.67, 2.42 ± 0.61, and 3.58 ± 0.95% Сorg, respectively, while the plowing layers of arable soils contain 1.36 ± 0.40, 1.71 ± 0.40, and 2.84 ± 0.86%, respectively. Structural (particulate organic matter 0.05–2 mm in size, CPOM, and mineral-associated organic matter <0.05 mm in size, CMAOM) and process (potentially mineralizable organic matter, C0, and microbial biomass, Cmic) pools were isolated in the organic matter of samples from different horizons of gray forest soils (Luvic Retic Greyzemic Phaeozems (Loamic)) under small-leaved forest and barley crop. The CPOM/CMAOM ratio in the upper soil horizons under forest and arable land was 0.60 and 0.26, respectively, and this ratio decreased with depth to 0.05 under both land uses. The sizes of the CMAOM, CPOM, C0, and Cmic pools correlated with each other and depended on the depth of the soil horizon, while the effect of land use on the pool ratios was found only for the surface horizons. The contribution of CPOM and CMAOM to the potentially mineralizable pool of organic matter in gray forest soil was 20–41 and 71–87%, respectively. According to the obtained data, the size of the C0 pool was almost equal to the annual amount of the heterotrophic CO2 emission from the soil. It was emphasized that determining of the sizes and ratios of structural and process soil organic matter pools should be important in the programs of carbon monitoring and recarbonization of agroecosystems.

Green Manuring and Irrigation Strategies Positively Influence the Soil Characteristics and Yield of Coriander (Coriandrum sativum L.) Crop under Salinity Stress

This study shows the influence of soil salinity and irrigation dose on biomass production and its impact on some edaphic indicators and functions. For this purpose, an experiment was carried out in two representative soils from Murcia (SE Spain), one slightly saline (LS) and the other saline (S), where an oat–vetch green manure was intercalated between a spinach cycle and a coriander cycle; the latter being subjected to three different irrigation doses (deficient, optimum and surplus). Rapid response indicators (ECext, cations and anions in the soil solution, etc.) were monitored, as well as the material balances, in particular C and salts. Green manure and crop residues increased soil OC by 12.5% and reduced Na+ and NO3− concentrations. Total biomass production was also affected by salinity, both in oat–vetch, 35.9 and 31. 9 tm ha−1 in LS and S, respectively, and in the coriander crop, where the irrigation dose was decisive, obtaining around 29 tm ha−1 with the optimum and surplus doses and significantly lower amounts with the deficit dose: 20.4 tm ha−1 in LSD and 14. 0 in SD. Therefore, it is necessary to adjust the irrigation doses, since deficit irrigation significantly reduces production and the surplus does not lead to an increase with respect to the optimum, while also causing ions to leach to depth horizons, as is the case for NO3−, Cl− and Na+, with the consequent risk of contaminating the water table.

ПОЧВООБРАБАТЫВАЮЩИЕ ФРЕЗЫ ДЛЯ ОСНОВНОЙ ОБРАБОТКИ ПОЧВЫ И ВОССТАНОВЛЕНИЯ ЗАДЕРНЕННЫХ УГОДИЙ

Milling is one of the most effective methods of processing of heavy over-compacted soils, recultivation of blackened lands and development of virgin and fallow lands. As a result of intensive loosening and mixing of the soil, the mineralization process accelerates. When choosing the type of milling unit and its operating modes, the depth of the humus horizon, the type and density of the soil, the thickness of the sod, the presence of shrubs, stones, stumps, hummocks, the microrelief of the soil, the contamination with rhizomatous and other weeds are taken into account. (Research purpose) The research purpose is analyzing the used tillage cutters for basic tillage and the returning of blackened lands into circulation. (Materials and methods) Considered the design features of tillage cutters used in basic tillage and in blackened areas. Systematized data about them. (Results and discussion) It was determined that various designs of cutters make it possible to effectively grind blackened and compacted soil, destroy above-ground vegetation, and level the surface soil layer. It was found that effective processing of blackened lands includes grinding the sod and embedding it in the soil to a depth of 20-25 centimeters, creating a loose homogeneous fertile soil layer. (Conclusions) Milling allows high-quality processing of heavy, including blackened soils. The technological operation of milling provides shredding of weeds, uniform processing of fields and leveling of the surface layer, increasing the air permeability and infiltration properties of soils, reducing the time to prepare for pre-sowing treatment by combining several technological operations when using combined cutters.

ТЕХНОЛОГИЧЕСКИЕ РЕШЕНИЯ ПО ЭФФЕКТИВНОМУ ВОВЛЕЧЕНИЮ МИНЕРАЛЬНОГО СЫРЬЯ МЕСТОРОЖДЕНИЙ КАРБОНАТНЫХ ПОРОД

The article presents the results of studies of an effective technology for the development of elongated deposits of carbonate rocks, the novelty of which lies in the sequence of combined opening of the deposit, combined with the features of the separation of cargo flows of overburden rocks and minerals, as well as in the placement of primary processing facilities in the area of the worked-out space of the quarry and underground workings, together ensuring a reduction in the average coefficient of overburden and the earth capacity of open mining operations. It is proved that by varying the depth of the concentration horizon in the established technological corridor, depending on the deterministic group of the quarry, it is possible to achieve a reduction in the level of total operating costs up to 7.5%, which for large deposits amounts to tens of billions of rubles. The results of the research can be useful in substantiating the technology of the development of a deposit of carbonate rocks.

Effect of ammonium and potassium nitrate on winter hardiness and yield of winter rye (<i>Secale cereale</i> L.)

The results of research for 3 years (2019–2021) on winter rye (Secale cereale L.) crops in the North-West region of the Russian Federation (Leningrad region) are presented. The effect of different doses and timing of ammonium and potassium nitrate application on winter hardiness and productivity of winter rye plants on the example of Volkhova and Eureka varieties was studied. The soil in the experimental fields was sod-podzolic loamy with the depth of the arable horizon of 20–25 cm. Humus content – 2.0–2.3%, pH of the salt extract – 5.2–5.5. Fertilizers were applied in dry form in the autumn one week after the emergence of the seedlings, and in the spring – at the resumption of vegetation. The studied fertilizer doses in terms of active substance for nitrogen were 0 (control), 30, 60 and 90 kg/ha. It is shown that winter hardiness of both varieties practically did not depend on the doses and timing of the application, as well as on the type of fertilizers. The maximum grain yield was shown by the Volkhova variety at a dose of nitrogen of 60 kg/ha, the Eureka variety – 90 kg/ha, with the maximum yield of the Eureka variety for all the years exceeding that of the Volkhova variety by 24.5%. Within the specified doses of nitrogen for both varieties, the best option was a single spring application of a mixture of ammonium and potassium nitrate, the worst - a single spring application of ammonium nitrate alone. On average for both varieties, potassium nitrate application in spring increased the grain yield by 16% compared to the variants where potassium nitrate was not used.

What happens to trees and soils during five decades of experimental nitrogen loading?

High deposition of nitrogen was postulated to drive losses of NO3- and nutrient base cations, causing soil acidification, nutrient deficiencies reducing tree growth and ultimately tree mortality. We tested these predictions in a uniquely long-term study involving three NH4NO3 addition treatments (N1-N3) in a boreal Pinus sylvestris forest. The lowest level (N1), 30 kg N ha−1 yr−1 was applied during 50 years. Twice this rate (N2) was added 38 years, followed by 12 years of recovery, while thrice this rate (N3) was added 20 years followed by 30 years of recovery. We compared tree growth, changes in foliar and soil chemistry among treatments including control plots without N additions. As predicted, the N treatments lowered soil pH and reduced soil base saturation by around 50 %. They also lowered foliar levels of Ca, Mg, K, P and B initially, but after 50 years only Ca and Mg remained lower than in the control. Lack of B motivated a single addition of 2.5 kg ha−1 after ten years of N treatment. Tree stem growth became and then remained higher in N1 than in the other treatments through the 50 years of treatments. In N2 and N3, foliar δ15N increased during the N-loading phase, but declined during the recovery phase, indicating a return of ectomycorrhizal fungi and their role in tightening the N cycle in N-limited forests. In the terminated, initially highest N treatments, N2 and N3, the trees even show signs of returning to N-limitation. In these treatments, the soil base saturation remains lower, while the pH was only lower at 0–10 depth in the mineral soil, but not in the 10–20 cm depth horizon or in the superficial organic mor-layer. Accurately documenting the effect of N additions on forest growth required a long-term approach, where reasonable rates of application could be compared with extreme rates. Such long-term experiments are necessary to support forest management in achieving goals for developing future forests as they shift in response to major, global-scale changes.

Представяне на „Софтуер за потенциална относителна оценка и класификация по пригодност за земеползване на земеделските земи в България“

In 2023, I developed “Software for potential land use suitability classification of agricultural land in Bulgaria” (Radovanova, 2023). It works in MS Office terms, programmed entirely through Microsoft Excel. The software with the corresponding methodology is essentially an update of the legally adopted “Methodology for work on the cadastre of agricultural land in Bulgaria” (Petrov E. et al., 1988), and this was achieved by a newly developed “Methodology for potential assessment of agricultural land in Bulgaria” (Radovanova, 2020). Actual and potential assessment are fully comparable in terms of approach, scheme, parameters, etc. The difference between actual and potential assessment, as in the case of software, is that in the case of potential assessment of agricultural land, potential characteristics (subject to improvement by external intervention) are used. These characteristics are: depth of the humus horizon, soil reaction, humus content, groundwater level, stoniness of the plough soil and degree of salinity and/or alkalinity. For these characteristics, 86 newly developed Bonite scales and algorithms have been applied (Radovanova, 2020). The software uses the built-in functions of Microsoft Excel. The mechanism of the existing final land use suitability categorisation of the assessed land is fully maintained, but is now considered in a “potential” aspect and uses the new potential algorithms. The software allows the printing of an official document of the potential assessment of the agricultural land concerned.

Flood Risk Mapping: Quantifying Topographic Wetness Index to Determine Flood Risk Zones for Mutoko District in Zimbabwe

Slope and topography help to describe the shape and relief of the land, allowing the hydrological and terrain analysis of a region by generating topographic wetness index (TWI). In this study the TWI is calculated using a digital elevation model raster layer. Spatial analyst tool and map algebra in ArcGIS was utilized to calculate slope, flow direction, flow accumulation, radian of slope, flow accumulation scaled, tan of slope, and ultimately TWI. Given that the TWI concept is less suitable in flat areas due to undefined flow directions, Mutoko District was chosen for this study due to its variations in topography. The index helps to quantify topographic control on hydrologic processes, terrain driven variation in soil moisture, and is highly correlated with several soil attributes such as horizon depth, silt percentage, organic matter content and phosphorous. However, TWI utilizes topographic elements of landscape to determine water flow and accumulation, and does not take into account additional information such as soil type or rainfall, which would be necessary for comprehensive assessment of flood risk zones. Availability of meteorological and hydrological data in addition to a digital elevation model (DEM), provides a more dynamic approach for comprehensive analysis, allowing dynamic simulations of spatially distributed water storage that can be used to derive alternative wetness indices

Gravity and magnetic exploration applied to iron ore deposits in the Sierra Grande area, Río Negro Province, Argentina

AbstractThe Ordovician–Devonian Sierra Grande Formation, Río Negro Province, Argentina contains three quarzitic members with two iron horizons. Its South Deposit includes both iron horizons. However, the East Deposit is relatively unknown, lacking information about geometry, depth and reserves. To answer these questions, we apply geophysical methods for the rapid evaluation of the East Deposit, using gravity and magnetic measures. The processing of these data allows the suggestion of two 2D models for calculating thicknesses, angles and depth of the iron horizons. The adjustments between the calculated and the observed curve are less than 6%. One model proposes the existence of the Alfaro iron horizon, and the other one proposes the presence of the Rosales iron horizon at depth. The Bouguer anomaly gravimetric maps allow us to calculate the mineral mass, resulting in 125 million iron tons. Thus, this study allowed us to calculate the thicknesses, angles and depth of both iron horizons, and to adjust and evaluate the mineral reserves with the maximum reliability that potential methods allow when applied to mineral prospecting. These results provide new and valuable information for future mining prospects.

GEOCHEMISTRY FEATURES OF ALUMINUM IN OILS AND CLASSIFICATION OF THE DEPOSITS OF THE DNIPRO-DONETSK DEPTH ACCORDING TO ITS CONTENT

Problem Statement and Purpose. The purpose of this publication is to establish, on the basis of geochemical studies of oils, the specifics of the relationship between aluminum concentrations and the content of other impurity metals, the values of the main mining, industrial and technological parameters and indicators of oils and their deposits, and to develop a natural classification of oil deposits on the example of Dnipro-Donetsk depth by content aluminum. Solving the task of the article will contribute to the development of a set of predictive criteria for hydrocarbon accumulations and the scientific substantiation of the geological-economic, technological and ecological assessment of their use, which in turn determines the relevance and practical value of the conducted research. Data & Methods. The factual basis of the work was the results of analyzes of metal content in oils from 36 deposits. At least 30 oil samples from each deposit were tested for metal content using X‑ray fluorescence analysis on an energy-dispersive spectrometer. All values of metals concentrations and their technological parameters were normalized to bring the information to the same scale, regardless of the units of measurement and the scale of the samples. Calculated normalized values of indicators of oil samples from each deposits were processed using the STATISTICA 11.6 program, which performed the calculation of descriptive statistics, correlation, regression, cluster analyzes and graphical visualization of the results of the performed studies. Results. It has been proven that the aluminum content in the oils of the considered deposits is inversely correlated with the following factors: concentrations of Ni, Fe, asphaltenes, the average capacity of the productive horizon, the current temperature of the productive horizons, the values of the current pressure in the productive horizons, the current depth of the productive horizons, the mineralization of the reservoir water from productive horizons, the density of formation water from productive horizons. And direct correlation with paraffin content, oil viscosity values, resin content, boiling point, V / Ni concentration ratio, total metal content, oil density values, Zn, Mn, S, Hg, Cr, V, Co concentrations. A natural classification of Dnipro-Donetsk depth deposits based on aluminum content in oils has been developed. The results of correlation and cluster analyzes were interpreted in genetic terms, which made it possible to establish a list of deposits formed by oil of abiogenic origin.

Water table effect on phosphorus solubility in biosolids‐amended soils

AbstractThe predominantly coarse texture of Florida Spodosols, limited P‐holding capacity, and fluctuating water table present major challenges for management of P, particularly in agricultural areas receiving biosolids. This study evaluated the impacts of water table level on P fate in Spodosols with contrasting P‐management histories. Treatments were a combination of soils with different biosolids histories (control [no biosolids], intermediate and high [biosolids‐P loads of 567 and 706 kg P ha−1, respectively]) and two moisture regimens (drained and flooded [water table at the depth of spodic horizon or 2 cm above soil surface, respectively]). Soil samples (A, E, and B horizons) were packed into PVC columns (96 cm tall, 11 cm in diameter), mimicking the soil profile. Leachate and pore water samples were collected at 2‐week intervals for 20 weeks. Regardless of treatment, proportion of P leached was low (∼0.2% total P mass). This was due to the significant P storage provided by the spodic horizon. Despite elevated soil P levels, Al and Fe added with biosolids reduced P solubility by as much as 55% compared with the control. Although flooding increased P leaching due to the reductive dissolution and hydrolysis of Al‐P and Fe‐P compounds, moisture regimen effects were generally negligible and inconsistent. Soil P storage capacity has been used as a risk assessment tool to determine biosolids‐P applications; however, our data demonstrated that additional field studies are needed to validate this concept, particularly its applicability and interpretation in biosolids‐amended soils that contain appreciable amounts of Fe‐ and Al‐organic complexes.

ANTHROPOGENIC TRANSFORMATION OF THE LYUTITSA RIVER BASIN

The Liutytsia is a typical small river of the Polissya part of the Volyn region. It flows through the territory of Rozhyshche and Kopachivka united territorial communities. The river is 37 km long, with a catchment area of 208 km2, 3.6% forest cover, 1.4% marshland, and 60.5% ploughed. About 10,000 people live within the basin. The territory has long been developed. Agricultural use predominates. Specialisation: growing potatoes, cereals, industrial crops, dairy and meat farming and processing of agricultural products. In the structure of land use in the basin, 87.6% of the land is used for agricultural purposes. All land available for agricultural use has been ploughed and is actively used. Within the basin, the permissible land use limits are exceeded. This contributes to the aggravation of the environmental situation and requires the implementation of measures for the rational use of natural resources and nature protection. 8.8% of the basin's territory is occupied by settlements, industrial, transport, communications, etc. The basin's water resources are also actively used. Most of the water is used for water supply to the population, industry and agriculture. In a year of 95% runoff availability, total water withdrawals exceed 20% of the annual runoff, and irreversible water consumption in the basin is 15%. In the future, runoff shortages may become a problem in low-water years. The frequency of dry years has been increasing recently. The concentration of most chemicals in the river water does not exceed the maximum permissible concentration. The content of ammonium nitrogen exceeds the per capita values by 15.6 times in the first and 2.92 times in the river channel 2, nitrite nitrogen by 1.7 times and 1.91 times, respectively, and total iron by 16 times and 2.4 times. The excessive content of nitrogen compounds is caused by surface runoff from urban areas, fields, farms, and spontaneous solid waste dumps. The area of drained land within the basin is 8,606 thousand hectares, with a land reclamation rate of 41.4%. There are 5 drainage systems within the basin. Soil overdrainage is widespread within the basin's drainage systems, leading to loss of soil cohesion, loss of vegetation cover and deflation. With distance from the drainage network, water drainage is worse, there are waterlogged areas, rewetting occurs due to inefficient drainage channels that are silted and overgrown with vegetation. Some reclaimed areas have not been ploughed for many years and are overgrown with selfseeding. Hazardous exogenous processes are occurring within the basin: karst, secondary waterlogging, and siltation of the riverbed. Soils are also undergoing negative changes. Erosion processes are occurring, the depth of the humus horizon is decreasing, and the content of humus and plant nutrients is decreasing. Environmental problems in the basin include: violation of water protection zones, ploughing and rewetting of the floodplain; lack of hydroecological monitoring in the river basin; poor condition of drainage systems; lack of soilprotective technologies for growing crops, violation of recommendations for the use of drained land; illegal landfills in the basin; low forest cover, lack of protected areas within the basin, lack of an effective local ecological network.
 Keywords: river basin, geoecological state of the basin, sources of anthropogenic impact within the basin, anthropogenic transformation of the basin.