Soil Pits Research Articles

Bailout test, HYDRUS‐2D, and analytical modeling for estimating permeability of ephemeral stream bed

AbstractAccurate estimation of effective saturated hydraulic conductivity (Ksat) of a vadose zone with an underlying shallow perched aquifer is challenging. Standard pumping tests and double‐ring infiltrometers are unsuitable for this purpose. Therefore, a bailout test (BOT) was conducted in nine soil pits to evaluate the hydraulic properties of the vadose zone and the subjacent shallow‐perched aquifer in a porous bed of a wadi in Oman. The analytical (Kirkham's type) and numerical (HYDRUS‐2D) models were also used. Upon instantaneous emptying, the water level rises in a pit, owing to seepage from the ambient shallow aquifer. The draw up was monitored and compared with modeling, which assumes a homogeneous or layered van Genuchten's soil. The soils of the excavated pits were characterized as sandy‐textured, gleyed, and containing calcareous and clay‐enriched layers. A good match between HYDRUS‐analytical results for layered soils and an idealized homogeneous one illustrates that BOT is a robust and quick technique for the estimating Ksat = 2–3 cm/h in the coarse‐textured wadi bed vadose zone overlaying a transient water table. BOT is better than classical auger hole tests because they test a larger soil volume through induced seepage. BOT is also more suitable for drainage trenches and other excavations, allowing for easier observation, soil sampling from the banks, and rapid dewatering.

Multi-Sensor Soil Probe and Machine Learning Modeling for Predicting Soil Properties

We present a data-driven, in situ proximal multi-sensor digital soil mapping approach to develop digital twins for multiple agricultural fields. A novel Digital Soil CoreTM (DSC) Probe was engineered that contains seven sensors, each of a distinct modality, including sleeve friction, tip force, dielectric permittivity, electrical resistivity, soil imagery, acoustics, and visible and near-infrared spectroscopy. The DSC System integrates the DSC Probe, DSC software (v2023.10), and deployment equipment components to sense soil characteristics at a high vertical spatial resolution (mm scale) along in situ soil profiles up to a depth of 120 cm in about 60 s. The DSC Probe in situ proximal data are harmonized into a data cube providing vertical high-density knowledge associated with physical–chemical–biological soil conditions. In contrast, conventional ex situ soil samples derived from soil cores, soil pits, or surface samples analyzed using laboratory and other methods are bound by a substantially coarser spatial resolution and multiple compounding errors. Our objective was to investigate the effects of the mismatched scale between high-resolution in situ proximal sensor data and coarser-resolution ex situ soil laboratory measurements to develop soil prediction models. Our study was conducted in central California soil in almond orchards. We collected DSC sensor data and spatially co-located soil cores that were sliced into narrow layers for laboratory-based soil measurements. Partial Least Squares Regression (PLSR) cross-validation was used to compare the results of testing four data integration methods. Method A reduced the high-resolution sensor data to discrete values paired with layer-based soil laboratory measurements. Method B used stochastic distributions of sensor data paired with layer-based soil laboratory measurements. Method C allocated the same soil analytical data to each one of the high-resolution multi-sensor data within a soil layer. Method D linked the high-density multi-sensor soil data directly to crop responses (crop performance and behavior metrics), bypassing costly laboratory soil analysis. Overall, the soil models derived from Method C outperformed Methods A and B. Soil predictions derived using Method D were the most cost-effective for directly assessing soil–crop relationships, making this method well suited for industrial-scale precision agriculture applications.

Различные формы Sr в агротемногумусовых подбелах юга Приморского края

To assess the concentration level and identify the main phase-carriers of various forms of strontium (Sr), the total content, distribution and concentration of water-soluble forms of the element in Albic Stagnosoils, which composed the bulk of the arable fund of the region under study, were studied. Full-profile soil pits were dug at the long-term fallow, phytoreclamative, and fertilized with mineral and organic fertilizer variants of the experience. The study of the different Sr forms contents was carried out by energy dispersive X-ray fluorescence spectroscopy and atomic absorption spectrometry. The main Sr volume was immobilized in the composition of soil mineral phase in soils of all variants of the experience. The addition of mineral fertilizers to soil was accompanied by an increase in the total content (by 6.4 %) and concentration of water-soluble (by 5,7 times) Sr forms, compared to the soil of fallow, and intensification of Sr sorption by Mn-containing soil compounds. The long-term addition of different types of organic fertilizers contributed to the activation of stable Sr-organic complexes formation. Under a green manure application in conditions of soil solution acidity decrease, the increase in the influence of Ca-containing soil compounds on the distribution of Sr has been shown. The soils of all variants of the experience were characterized by the absence of factors and conditions that contributed to the Sr accumulation in profiles, it was suggested by the lower total Sr content compared to the mean background content for surface soils around the world and to the mean content in agricultural soils in Japan.

Pedological Study under Cocoa Trees and its Implication on Production in Soubré, Southwest Region of Ivory Coast

Maintaining the fertility of cultivated soils in tropical countries such as Ivory Coast remains a major concern for producers because of crop failures. The aim of this study is to determine the soil characteristics of a cocoa plantation in the Soubré region (southwest of Ivory Coast: 6° - 7° N latitude and 5° - 7° W longitude), in order to improve production. In the centre of the plantation, a section of land (50 m × 50 m) was identified. Five soil pits were opened on this section of land, one at each corner and one in the centre. Soil samples were taken from each of the pits, in the 0-20 cm and 20-40 cm layers. Composite samples were then taken at these two depths for the analytical data. The pH, sum of exchangeable bases (S), cation exchange capacity (CEC), saturation rate of exchangeable bases (V), particle size fraction and organic matter content were measured and compared with threshold values known from the literature. The results show that pH (5.6 - 6.8) and assimilable phosphorus [P ass (130 - 350 ppm)] increase with depth and are in good proportion. Concentrations of potassium (K+ : 2.9 - 2.3 cmol/kg), calcium (Ca2+ : 29.1 - 47.2 cmol/kg) and magnesium (Mg2+ : 2.7 - 22 cmol/kg), as well as chemical properties (S : 35 - 73 cmol/kg, CEC : 48 - 80 cmol/kg and V : 73 - 90 %) are relatively good for cocoa production. However, organic matter (1.38%) and total nitrogen (N = 0.1 - 0.05%) are low. And high levels of clay (48%) and silt (23%) were noted from the first 20 cm depth. Spreading organic matter in the form of compost could therefore be recommended in order to correct the defective characteristics of the soils caused by the abundance of these two mineral particles: clay and silt, on the one hand, and deficiencies in nitrogen and organic matter, on the other.

Identification of Technosols formed from industrial dust in the area of Yazd city (Central Iran) by ground-based radiometry

Intensive industrial development in the form of metallurgical plants and quarries for mining of mineral resources in the vicinity of the city of Yazd resulted in significant dustiness of the ground layer of atmosphere and accumulation of industrial dust on the soil surface. At the locations of alloy steel production facilities, dust composition was dominated by particulate matter less than 1 μm (PM1), while near sand quarries, dust particles less than 10 μm (PM10) were predominant. The dust from these sources also differs in chemical composition (iron/silicon content ratio, pH). Registration with a pyranometer with a dark green filter with transmittance at a wavelength of 550 nanometers with a time interval of 20 seconds at a speed of 30 km/h during the movement along the specified routes allowed authors to identify zones with a stable increased content of particles of different sizes in the near-surface atmosphere. Sampling soil pits in these zones confirmed the presence on their surface of layers of dust deposits with a thickness of more than 5 cm, which allows them to be attributed to Technosols in accordance with the WRB soil classification. The soil map of the research area was compiled at a scale of 1 : 25 000 with the reflection of Technosols participation in the soil patterns. According to the map, more than three quarters of the study area are soil complexes including Technosols. Arid climatic conditions of the region lead to the accumulation of dust on the soil surface, which are practically not transformed and not removed from the soil, which results in their degradation and deterioration of the environmental conditions. Dust accumulation on the soil surface affects the state of vegetation cover of the region, which serves as a basis for indirect satellite indication of dusting zones. The method of revealing the dust layer on the soil surface based on the assessment of dustiness of the near-surface atmosphere using pyranometer can serve as a good complement to remote sensing methods.

Earthworm records and habitat associations in the British Isles

The National Earthworm Recording Scheme (NERS) is the most comprehensive national database of earthworm species occurrence records for the British Isles, and possibly for any individual country in the world. Utilising the NERS database, we sought to update the current knowledge of earthworm species occurrences in the UK, Ireland and Channel Islands; identify species-specific habitat and microhabitat associations; reveal any biases and complementarities between amateur naturalist and research-related earthworm record collection; and inform how future earthworm sampling can be better focussed to improve our knowledge of earthworm ecology. We found that the most commonly occurring earthworm species were present in farmland and woodland, and recovered via soil pit sampling, the most common habitat-sampling protocol combinations. However, several earthworm species showed specificity to alternative habitats (such as trees, wetlands, and compost), and association with microhabitat (non-soil) sampling. There were clear disparities between scientific researchers and amateur naturalist recorders in terms of habitat types visited and sampling protocols/microhabitats used in the collection of earthworm records. Most importantly, we found that earthworm species currently considered to be nationally ‘rare’ in the British Isles are significantly associated with the most under-represented habitat-protocol/microhabitat combinations (forest deadwood and other microhabitats, in addition to scrubland, wetland and heathland habitats), and thus may not be rare, only under-sampled. We therefore encourage earthworm researchers and recorders to give greater attention to these situations, to gain new insights into these earthworm species' ecologies and distributions. Finally, we would like to promote the establishment of earthworm recording schemes in other countries, to enable national and global collaborative monitoring of earthworm responses to environmental change.

Stability Analysis of Unsaturated Soil Pit Under Vehicle Load

Stability Analysis of Unsaturated Soil Pit Under Vehicle Load

Changes in carbon stocks according to stand development stages in oriental beech forests in the Marmara Region of Türkiye.

This study was conducted to determine the changes in carbon stocks of oriental beech (Fagus orientalis) according to stand development stage in the Marmara Region of Türkiye. For this purpose, sample plots were taken from a total of 32 areas encompassing four stand development stages (young, middle age, mature and overmature stand). The diameter at breast height and height of all trees in the sample plots were measured, and only three dominant trees's ages per plot were determined. Aboveground carbon stock was calculated using equations developed for beech forests, while the coefficients in the Agriculture, Forestry and Other Land Use guide were used to determine belowground carbon stocks. A soil pit was dug in each plot and soil samples were taken at different depths (0-10, 10-30, 30-60, 60-100cm). In addition, litters were sampled from four different 25 × 25cm sections in each plot, and then the physical and chemical properties of the soil and litters were analysed. The variations in carbon stocks in above- and below-ground tree mass, litter and soil, and in ecosystem carbon stocks according to development stage were examined by analysis of variance and Duncan test, and the relationships between the carbon stocks were investigated by correlation analysis. Aboveground (AG) and belowground (BG) tree, soil and ecosystem carbon stocks showed significant differences between the four stand development stages (P < 0.05), but not the litter carbon stocks (P > 0.05). AG and BG tree and ecosystem carbon stocks increased with progressive stand development stages, while the soil carbon stock was the highest at the young stage. These findings will contribute to the preparation of forest management plans and the national greenhouse gas inventory.

Assessment of salt-affected soil in selected rice irrigation schemes in Tanzania: understanding salt types for optimizing management approaches

Salt-affected soils have serious implications for agricultural land quality and productivity, leading to a reduction in the net cultivable area available for food production. This issue has emerged as one of the foremost global challenges in recent years, impacting both food security and environmental sustainability. This research focuses on soil characterizations conducted in three irrigation schemes to understand the types, distribution, and nature of salt-affected soils. Auger observations served as the basic methodology for soil unit delineation in this study. Twelve representative soil pits with a depth of more than 160 cm were described, and undisturbed and disturbed samples were collected and analyzed for physical and chemical properties. The schemes were characterized by low levels of available phosphorus, organic carbon, and total nitrogen, as well as variations in exchangeable bases. Furthermore, 37.5% of the analyzed horizons highlighted the presence of salt-affected soils. Sodium was the predominant cation, followed by magnesium, potassium, and calcium. Likewise, HCO3− was the dominant anion, followed by Cl− and SO42−. The results of this study reveal the existence of two types of salt-affected soil. Uturo irrigation scheme had sodic soils, while the Ndungu irrigation scheme had saline-sodic soils. Additionally, both sodic and saline-sodic soils have been discovered in the Mawala irrigation scheme. The root cause of this challenge is inherent soil conditions, exacerbated by inadequate drainage infrastructure. Therefore, measures such as the application of gypsum followed by salt leaching, improving soil drainage by incorporating organic matter, improving drainage infrastructure, and using rice-tolerant varieties are recommended to mitigate salt stress and improve soil fertility. It is imperative to establish a robust framework for continuous monitoring and regular assessment of soil health to enable timely interventions and informed decisions for sustainable agricultural management.

Earthworm Watch: Insights into urban earthworm communities in the UK using citizen science

The distribution of earthworm ecological groups in urban areas is not well-known, despite their crucial role in delivering soil ecosystem services such as nutrient cycling and water drainage. Citizen science engages public audiences in the scientific research process and is an excellent tool for collecting biodiversity data in urban areas, where most of the UK population resides. However, a disadvantage is that differing levels of skill and engagement among participants can create statistical challenges. The Earthworm Watch citizen science project used 668 matched-pair surveys to estimate how the abundance and ecological diversity of earthworms respond to land management practices, and soil properties in UK urban habitats. A total of 5170 earthworms were counted during the project with a mean of 8 earthworms per soil pit - equivalent to a density of 198 earthworms per m2. Soil moisture and texture were the largest drivers of total earthworm abundance, with habitat borderline statistically insignificant. Endogeic earthworms were found in 71 % of soil pits, epigeic in 62 % and anecic in 33 %. Fertiliser use also had a significant effect on total abundance, but only when organic fertiliser was used. Earthworm ecological groups demonstrated varied responses to habitat, with endogeic earthworms consistently the most abundant group, showing slight preferences for grasslands and vegetable beds. Anecic earthworms had the lowest abundance across all habitats but were more prevalent in grasslands and vegetable beds. Epigeic earthworms were most abundant beneath shrubs and hedges. These findings align with expected patterns of earthworm ecology, underscoring the potential of well-designed citizen science projects to yield valuable insights into urban earthworms and soil health.

The transition from shifting cultivation to indigenous agroforestry as nature-based solution for land restoration in the Indian Eastern Himalayas

In the Indian Eastern Himalayas, shifting cultivation has long been a major cause of land degradation. However, indigenous communities, like the Hmar, have successfully transitioned from shifting cultivation to agroforestry systems such as pineapple agroforestry, leading to land restoration and increased household incomes. Despite these positive outcomes, little is known about how soil health indicators change during this transition. Thus, the present study aimed to investigate changes in selected soil health indicators and erodibility across different age classes of pineapple agroforestry systems (<5, 5–10, 11–15, and > 15 years old) compared to shifting cultivation and nearby natural forests. Soil samples were collected from six sites, including different stages of pineapple agroforestry systems, shifting cultivation phases, and a natural forest. At each site, three (10 × 10 m) quadrats were selected, and two (1 × 1 × 1 m) vertical soil pits were dug in each quadrat, sampling soil depths from 0 to 100 cm. The transition from shifting cultivation to pineapple agroforestry improved soil organic carbon (SOC) and stratification ratios while reducing soil erodibility. SOC stocks were estimated at 182.7 Mg C/ha for natural forest land and 188.2 Mg C/ha for the cropping phase in shifting cultivation. On the other hand, estimated SOC stocks for < 5, 5–10, 11–15 and > 15 years old stands of pineapple agroforestry system were 169.7 Mg C/ha, 157.2 Mg C/ha, 168.9 Mg C/ha and 177 Mg C/ha respectively. Thus, the estimated SOC stocks under > 15 years of pineapple agroforestry were comparable with adjacent natural forest land. The stratification ratios (SR > 2) for SOC and macronutrients indicated better soil quality in the pineapple agroforestry system than in the cropped land. The clay and modified clay ratios decreased with increasing age of pineapple agroforestry stands. The highest clay ratio was recorded in the topsoil of < 5-year-old pineapple agroforestry system, indicating a greater risk of exposure to rainfall events than in natural forest land and the cropping phase in the shifting cultivation cycle. It is concluded that transitioning from shifting cultivation to a pineapple agroforestry is a nature-based solution to restore degraded lands and presents an excellent opportunity for sustainable soil health and carbon sink management.

Traditional gold mining in the highlands of Ethiopia: Its effect on soil loss and possible reclamation measures

Traditional gold mining (TGM) is among the off-farm income sources of smallholder communities in the highlands of Ethiopia. However, information on their impact on land degradation, taking soil loss as a key indicator, was scant. Hence, this study aimed at i) analyzing local communities’ attitudes toward TGM practice, ii) TGM impact on soil loss, and iii) possible restoration measures for the degraded gold-mined landscapes. For the evaluation of community perceptions, 96 beneficiaries were selected from three gold mining sites following stratified random sampling techniques. Soil loss measurement was done through measurement of i) the mass of soil excavated and transported to the river (TR) from 96 individuals and ii) soil volume excavated in 45 excavated soil pits (EP). Descriptive statistics and one-way ANOVA were used to analyze soil loss data, while community perception was analyzed qualitatively. The survey results indicated that the average soil loss from TR and EP were 6,075.97±8.9 t ha-1 yr-1 and 32,549.99±753.68 t ha-1, respectively. The magnitude of soil loss also showed a significant (p&lt;0.001) difference among the three sites. Due to a lack of awareness and hiding the reality, most of the gold miners believe that TGM practice has no negative impact on the soil resource, and no post-mined reclamation strategy is implemented. It can be concluded that the existing TGM practices are not done in an environmentally friendly approach and result in adverse soil loss. Hence, stabilizing the topography of the mined sites via backfilling of mined pits and topsoil conservation and amendment measures can be suggested.

Persistent microbial communities in hyperarid subsurface habitats of the Atacama Desert: Insights from intracellular DNA analysis.

Desert environments constitute one of the largest and yet most fragile ecosystems on Earth. Under the absence of regular precipitation, microorganisms are the main ecological component mediating nutrient fluxes by using soil components, like minerals and salts, and atmospheric gases as a source for energy and water. While most of the previous studies on microbial ecology of desert environments have focused on surface environments, little is known about microbial life in deeper sediment layers. Our study is extending the limited knowledge about microbial communities within the deeper subsurface of the hyperarid core of the Atacama Desert. By employing intracellular DNA extraction and subsequent 16S rRNA sequencing of samples collected from a soil pit in the Yungay region of the Atacama Desert, we unveiled a potentially viable microbial subsurface community residing at depths down to 4.20 m. In the upper 80 cm of the playa sediments, microbial communities were dominated by Firmicutes taxa showing a depth-related decrease in biomass correlating with increasing amounts of soluble salts. High salt concentrations are possibly causing microbial colonization to cease in the lower part of the playa sediments between 80 and 200 cm depth. In the underlying alluvial fan deposits, microbial communities reemerge, possibly due to gypsum providing an alternative water source. The discovery of this deeper subsurface community is reshaping our understanding of desert soils, emphasizing the need to consider subsurface environments in future explorations of arid ecosystems.

Ground-penetrating radar investigation of regolith thickness on a periglacial alpine summit flat, Uinta Mountains, Utah, USA

ABSTRACT Summit flats are low-relief, gently sloping landforms common in periglacial mountain environments. Apart from at their edges where summit flats are truncated by glacial headwalls and at their crests where isolated tors are occasionally present, bedrock is typically mantled on a summit flat by a continuous layer of regolith. This study applied ground-penetrating radar (GPR) to survey the thickness of regolith on a summit flat in the Uinta Mountains (Utah, USA). More than 500 m of GPR data were collected along transects extending from the edge of the summit flat to the crest, as well as adjacent to a deep soil pit. Results indicate that the regolith thickness is quite variable, with a mean of 91 ± 38 cm when calculated with an appropriate radar velocity. Because the ground surface of the summit flat is notably smooth, the variability in thickness is a consequence of irregularities in the bedrock surface at depth, which is significantly rougher. Recognition that regolith thickness can vary considerably beneath an alpine summit flat has implications for soil formation, carbon storage, and the transmission and storage of shallow groundwater, as well as evolutionary models for periglacial mountain landscapes.

Relative and absolute difference in soil organic carbon stocks in grassland soils in Ireland: Impact of rock fragments, bulk density and calculation methods

On-farm management measures can sequester carbon by removing carbon dioxide from the atmosphere and storing it securely for long periods, in our soils. Estimates of soil organic carbon (SOC) stocks differ by calculation methods in terms of how they account for the coarse >2 mm fraction (i.e. rock fragments) of the soil. Irish grassland soils have variable volumetric stone contents and the extent of overestimation is unknown. Without best practice guidance, calculations of SOC in these soils are vulnerable to overestimation. The objectives of the present study for grassland soils in Ireland were to: 1) calculate mean SOC stocks using different methods by soil horizon and volumetric stone content class; 2) highlight relative differences in SOC stocks between these calculation methods and 3) compare normalised layer (Ly, fixed depth) versus horizon (Hz) type derived sampling data in terms of SOC stocks, to establish a best practice standardised sampling protocol. Five methods (M, 1–3 overestimate SOC stocks, whereas 4–5 are equivalent and are closest to reality) to calculate SOC stocks were used in combination with three soil databases i.e. Irish Soil Information System (I-SIS), the Heavy Soils Programme (HSP) and the Soil Quality Assessment Research Project (SQUARE). Objectives 1 and 2 were assessed using all three databases across methods, whereas objective 3 used the SQUARE database and M4. These data were sorted into volumetric stone content (%) classes (< 5%, 5–10%, 10–20%, 20–30% and > 30%) and sampling horizon (O, A, E, A/B, B, B/C, and C) with SOC stocks calculated using M1–5 equations. Results confirmed the high volumetric stone content assumption of grassland soils in Ireland (exception O horizons). Volumetric stone contents ranged from 0% to 36% for all horizons. When M1–5 are considered the average relative difference in SOC stocks between M1 and M5 was 18.9% (max: 388%), M2 and M5 was 7.7% (max: 60.7%) and M3 and M5 was 8.9 (max: 310%). In terms of Ly versus Hz sampling, no significant differences were found for the A horizons sampled. However, in Ireland, best practice should still utilise elements from both Ly (using an auger to get fixed depth soil samples; analysed for organic C) and Hz (using a soil profile pit to extract representative BD cores and to gather bulk samples for volumetric stone content analysis) approaches in the field. Laboratory methods used must fit with the needs and assumptions of equations M4/5 to calculate SOC stocks (thereby minimising overestimation and indeed underestimation).

Soil water storage capacity and soil nutrients drive tree ring growth of six European tree species across a steep environmental gradient

Tree growth depends on tree-intrinsic attributes, synecological interactions, atmospheric conditions and soil properties. While the influence of tree factors and climate are analysed in detail in many studies, the effect of soil properties is less investigated and compensatory soil effects are often not quantified. In this study, we use a comprehensive dataset of 1659 tree increment cores from six common Central European tree species (Abies alba, Fagus sylvatica, Larix decidua, Picea abies, Pinus sylvestris, Quercus spp.) sampled at 1562 locations across large environmental gradients in the Eastern Alps. Soil data was available from an extensive soil survey including soil pits, laboratory analysis and the application of pedotransfer-functions. Up to three main tree species per site were sampled and the tree ring widths were dendrochronologically measured and synchronized. Topographic information from a high-resolution Digital Terrain Model, high-resolution climate data and biometric measures were available at each site. To determine the influence of soil water storage capacity and soil nutrient status, we used generalized additive models to expand standard models of well-known drivers of tree growth, including age, climatic water balance and temperature. For the time span of 38 years from 1981 until 2018, we found species-specific impacts of soil properties on tree ring growth. Specifically, soil water storage acted as a buffer to overcome drought periods, in particular for deep rooting tree species like Quercus spp. and Abies alba. In addition, we found species-specific growth reactions to soil nutrient status for nutrient-demanding species likes Fagus sylvatica but no effects for less demanding tree species like Pinus sylvestris. Our results show the magnitude of the effects of soil properties in relation to other growth factors on radial growth of six Central European tree species. Therefore, we posit that, while age and climate do have a stronger influence on tree growth, it is important to consider soil as a growth factor, particularly at the distribution margins along climatic gradients.

Influence of Deep Foundation Pit Excavation on Adjacent Pipelines: A Case Study in Nanjing, China

To investigate the pipeline deformation pattern caused by the excavation of deep foundation pits in composite soil–rock strata, a comprehensive study integrating on-site monitoring and numerical simulation was conducted. This study centered on a deep foundation excavation project in the soft soil in Nanjing’s floodplain region. The analyses of pipeline settlement and deformation were performed based on field-measured data. This study investigated the impact of excavation on the mechanical properties of the surrounding soil that resulted in the progressive deformation of adjacent pipelines. Furthermore, numerical simulations were conducted using Plaxis 3D CONNECT Edition v22 finite element analysis software. This study elucidated the influence of factors such as pipeline–pit distance and burial depth on pipeline deformation, conducting a quantitative analysis of their effects. The results indicated that deformation primarily occurs unevenly near pit corners and is less pronounced in soil–rock strata than in single-type soil layers. This study established correlations between pipeline displacements and various factors, offering valuable insights for future excavation projects conducted under similar conditions.

Soils of the Avam forest-tundra (Southwestern Taimyr)

The purpose of the study was to describe the common characteristics of the soil cover of the poorly studied territory of the Avam tundra. Location and time of the study. The soil survey was conducted during the summer season (end of July – mid of August) 2021 in the North Siberian lowland in the middle Dudypta River, 45–60 km to the north of the Central Siberian Plateau. Methodology. Soil pits (24) were dug at three key sites, in the most typical habitats. The main soil chemical properties were determined in 53 samples from 13 pits. The main results. The soils of automorphic conditions were identified as Cryosols on the loams and as Arenosols on sands and sandy loams. Under difficult drainage, Gleyic subtypes of these soils or Gleysols are common. Zonal Cryosols are more typical for larch woodlands mostly in the eastern part of the territory. Arenosols are distributed mainly on the sandy sowback in the eastern part, and on the second above-floodplain terrace of Dudypta and Kystykhtakh. Arenosols microcomplexes are common for the spotted tundra of the second above-floodplain terraces. On sandy loam and loamy sediments, upper gleyic layer is formed under the spots. These soils are interbedded with upper gleyic Cryosols. The floodplains are occupied by Humic Fluvisols, and Histic Gleyic Fluvisols of the first floodplain terrace. Conclusion. In general, the soils, typical of the Taimyr forest-tundra, are common in the surveyed territory. Given the limitations of our research on the most drained parts of the terraces, the location of podburs may be a characteristic feature of this particular part of the terraces. It can be assumed that in the central, more hydromorphic parts of the local watersheds, the Gleysols are more common.

Chernozem properties and agricultural status under different land use in the forest-steppe of West Siberia

The aim of the study was to assess changes in soil properties and agrochemical status under different land use (undisturbed, abandoned and agricultural) in the forest-steppe of West Siberia. Location and time of the study. Soil samples (27 in total) was performed in tge Iskitim district (Novosibisrk region, Russia) in summer 2020 from the soil pits along the entire profiles rom soil genetic horizons at three sites: (US) undisturbed meadow steppe with legumes, herbs and grasses (54,668˚ NL, 83,125˚ EL); (PS) agricultural site with ploughed soil, at the time of sampling under barley, oats and vetch mixture(54,668˚ NL, 83,125˚ EL); (AS) dry stepped meadow of grasses and herbs that had been abandoned for 27 years prior to sampling (54,666˚ NL, 83,098˚ EL). Site US soil was classified as clay illuvial shallow chernozem, site PS soil was classified as dark clay illuvial shallow agrozem, whereas AS soil was identified as clay illuvial postagrogenic shallow agrochernozem (according to the Russian classification). According to the IUSS Working Group WRB classification, US and AS soils were Luvic Greyzemic Chernozem (Siltic), whereas PS had Luvic Greyzemic Chernozem (Siltic, Aric). Methods. Soils were analyzed for organic ans carbonate carbon content, total and nitrite nitrogen, mobile phosphorus content, exchangeable calcium, as well as exchangeable and unexchangeable potassium and magnesium. Soil pH was measured potentiometrically. Soil granulometry was estimated by pipette technique after dispersion in sodium pyrophosphate. Main results. The presence of sod (horizon AUrz) and powdery grains of biogenic structure of the humus horizon are the main features of the undisturbed chernozem. The grainy soil structure was destroyed by ploughing, and, consequently, could not be found in the agrozem. Restoration of these features is important indicator of the postagrogenic transformation. As compared with the US soil, the AS one showed lower humus and total nitrogen content and stocks, especially in the ploughed horizon, but the difference was not statistically significant. These soil properties were found to be increased after 27 years of postagrogenic spontaneous restoration at the AS site. According to the studied soil properties, the agrochemical status of the studied undisturbed, abandoned and ploughed soil can be described as favorable for plant growth and crop production. Conclusions. The studied chernozems of the forest-steppe in West Siberia (undisturbed, ploughed and abandoned sites showed differences in their profile and surface horizon structure, carbonate layer location, the contents of mobile phosphorus, exchangeable magnesium. The topsoil (0–5 cm) at the undisturbed and abandoned sites accumulates biogenic elements (organic carbon, total and nitrate nitrogen, easily mobile phosphorus and exchangeable potassium. The absence of the difference in soil properties between the three studied site proves chernozem to be rather resistant to agrogenic influence. The site that had been abandoned for almost three decades, can be once again put int agricultural use. It should be emphasized that in Siberia the crop yields, especially grains, on chernozems are produced mainly by soil resources of mobile microelements without compensation their removal by fertilization. The agrogenic transformation rate and degree of Siberian chernozems are higher as compared with the European part of Russia. Therefore, we recommend monitoring agrochernoems fertility, especially after abandoned land are put once again in the agricultural use.

Mechanical composition and physical properties of irrigated soils of the gijduvan district of Bukhara region

The mechanical composition and physical properties of soils in irrigated agriculture in the Gijduvan district of Bukhara region were studied. In the Hamid Olimjon district (Sarmijon) area, Omad farm soil pits (sections) were dug on the contour 576. In the Gulistan district, the contours of the Shukur Tokhta farm 282-283 and the contour 648 of the Hasan Rajabi farm of the Gijduvan region, and the mechanical composition and physical properties of the soil were analyzed from the samples taken. made the mechanical composition of the soil is light, medium and heavy sand, porosity is considered unsatisfactory.