Soil Resources Research Articles

Snowmelt and subsurface heterogeneity control tree water sources in a subalpine forest

AbstractIn high mountain areas, snowmelt water is a key—yet fading—hydrological resource, but its importance for soil recharge and tree root water uptake is understudied. In these environments, heterogeneous terrains enhance a highly variable availability of soil and groundwater resources that can be accessed by plants. We conducted a tracer‐based study on a subalpine forest in the Italian Alps. We investigated the isotopic composition (2H and 18O) of snowmelt, precipitation, spring water, soil water—at different locations and depths—and xylem water of twigs taken from alpine larch, Swiss stone pine and alpenrose plants during bi‐weekly field campaigns (growing seasons of 2020 and 2021). Mixing models based on δ18O revealed a large contribution of snowmelt to soil and xylem water, particularly during early summer. We investigated the contribution of water from different soil depths to xylem water, using the sap flow records to date back the end‐member signatures. We found a flexible use of shallow and deeper soil water by the investigated plants, with groundwater more likely used by larger trees and during the late summer. Results based on isotopic data were combined with geophysical observations of the subsurface structure to develop a conceptual model about the different exploitation of water by plants depending on their location (shallow soil on a slope vs. a saturated area). Our study highlights the relevance of snowmelt in high‐elevation terrestrial ecosystems, where heterogeneous substrates shape the water availability at different depths and, in turn, water uptake by plants.

Soil Microbial Community Structure and Carbon Stocks Following Fertilization with Organic Fertilizers and Biological Inputs.

The application of organic fertilizers and biological inputs to soil inevitably affects its quality, agrochemical indicators, and microbiota. Sustainable agriculture is based on continuously learning about how to properly manage available soil, water, and biological resources. The aim of the study was to determine changes in microorganism communities and carbon stocks in infertile soils for fertilization using different organic fertilizers and their combinations with bio-inputs. Genetic analysis of microorganism populations was performed using the NGS approach. Our study showed that the application of organic fertilizers affects the soil microbiota and the taxonomic structure of its communities. Specific groups of bacteria, such as Bacillota, were promoted by organic fertilization, meanwhile the abundance of Pseudomonadota and Ascomycota decreased in most treatments after the application of poultry manure. Metagenomic analysis confirmed that the use of bio-inputs increased the relative abundance of Trichoderma spp. fungi; meanwhile, a significant change was not found in the representatives of Azotobacter compared to the treatments where the bio-inputs were not used. The positive influence of fertilization appeared on all the studied agrochemical indicators. Higher concentrations of Corg and Nmin accumulated in the soil when we used granulated poultry manure, and pHKCl when we used cattle manure.

Increasing and fluctuating resource availability enhances invasional meltdown.

Exotic plant invaders can promote others via direct or indirect facilitation, known as "invasional meltdown." Increased soil nutrients can also promote invaders by increasing their competitive impacts, but how this might affect meltdown is unknown. In a mesocosm experiment, we evaluated how eight exotic plant species and eight Eurasian native species responded individually to increasing densities of the invasive plant Conyza canadensis, while varying the supply and fluctuations of nutrients. We found that increasing density of C. canadensis intensified competitive suppression of natives but intensified facilitation of other exotics. Higher and fluctuating nutrients exacerbated the competitive effects on natives and facilitative effects on exotics. Overall, these results show a pronounced advantage of exotics over native target species with increased relative density of C. canadensis under high nutrient availability and fluctuation. We integrate these results with the observation that exotic species commonly drive increases in soil resources to suggest the Resource-driven Invasional Meltdown and Inhibition of Natives hypothesis in which biotic acceleration of resource availability promotes other exotic species over native species, leading to invasional meltdown.

The development and utilization of shale oil and gas resources in China and economic analysis of energy security under the background of global energy crisis

The key scientific problem to be solved in this paper is the optimal development and utilization model and the economic evaluation model of China's land-phase shale oil and gas resources, and the purpose of the research is to promote the large-scale commercial development and utilization of China's shale oil and gas resources, and to safeguard China's oil and gas energy security and the sustainable development of the economy. The article proposes to adopt the small surface element volume method (oil content rate method) to evaluate the pure shale oil resources, adopt the Cobb–Douglas production function model as the optimization model to measure the boundary production capacity of shale oil and gas, construct the optimal development and utilization model for shale oil and gas resources considering the five first-level safeguard indexes, namely, science and technology (A), capital (K), talents (L), reserves (S) and ecological environment (E), and establish the basic constraint model for the optimal development and utilization of shale oil and gas resources. The basic constraint model, as well as the evaluation model of economic coefficients for the development and utilization of shale oil and gas resources were established. The pure shale oil resources are mainly calculated based on the movable oil content of shale. In the paper, the S1 of normal pyrolysis (300 °C) is regarded as movable oil, and the sum of S1 and evaporated hydrocarbon (light hydrocarbon) loss is the movable oil content of shale. The integrated geological-physical exploration-engineering comprehensive evaluation of China’s land-phase shale oil-rich and high-yielding “sweet spot” is an important prerequisite for the realization of shale oil and gas resources to build production scale and effective development, and the least-squares method is used to estimate the average production function, the distance to the maximum value of the residuals, and the boundary capacity production function. The average production function and residual maximum distance are estimated by the least squares method, and the production function of the boundary capacity is derived, and the quotient of the boundary capacity and the actual capacity is calculated to get the capacity utilization rate, which can be used to analyze the potential of future shale oil and gas growth. The development of shale oil and gas resources in a target block requires comprehensive consideration of the first-level guarantee indicators such as science and technology (A), capital (K), talents (L), reserves (S) and ecological environment (E), as well as more than 10 s-level indicators and a number of third-level indicators, in order to ensure that the oil companies maximize their profits by organizing the development and production. The economic coefficient can be expressed as the ratio of economically recoverable resources to geological reserves. The larger the economic coefficient for the development and utilization of shale oil and gas resources is, the better the economy of the area is, and the larger the proportion of shale oil and gas resources that can be exploited. There is little special literature on the optimal development and utilization model of shale oil and gas resources and energy security among many research results at home and abroad. The evaluation of pure shale oil using the small surface element volume method (oil content rate method) and the construction of the boundary capacity calculation model, the optimal development of the basic constraints model and the economic evaluation model that we have determined, although they can not yet fully cover all the links and factors related to the development and utilization of shale oil and gas resources, are not yet fully covered by our research work. However, our research work has given the model more geological and economic theoretical connotations, and provided an economic basis and technical reference for the large-scale and commercial development and utilization of shale oil and gas resources as an effective alternative to oil imports.

PROSPECTS OF CENTRAL ASIAN MARKETS FOR RUSSIAN OIL COMPANIES

This article is devoted to the current state of the oil sector in the Central Asian countries and an assessment of the prospects of their markets for expanding the presence of Russian companies. The author highlights the main factors that determine the current situation in the oil producing and refining industries in the region: the overall availability of energy resources in general and crude oil in particular, property rights to oil producing and refining enterprises and operating oil pipelines, as well as international agreements in this area concluded over the past five years. The article substantiates the conclusion that today the potential of the region as a transport and logistics corridor and a center for oil production and refining remains largely untapped. In this regard, for Russian companies, the greatest interest lies in measures to establish control over pipelines from countries focused on the export of oil and oil products (Kazakhstan and, to a lesser extent, Turkmenistan) and to strengthen the presence in the domestic markets of those countries that focus on importing energy resources (Kyrgyzstan, Tajikistan, Uzbekistan) by creating their own transport and refinement infrastructure.

The Production Analysis and Exploitation Scheme Design of a Special Offshore Heavy Oil Reservoir—First Offshore Artificial Island with Thermal Recovery

More and more offshore heavy oil resources are discovered and exploited as the focus of the oil and gas industry shifts from land to sea. However, unlike onshore heavy oil reservoirs, offshore heavy oil reservoirs not only have active edge and bottom water but also have different exploitation methods. In this paper, a typical special heavy oil reservoir in China was analyzed in detail, based on geology–reservoir–engineering integration technology. Firstly, it is identified as a self-sealing bottom water heavy oil reservoir by analyzing its geological characteristics and hydrocarbon accumulation mechanism. Secondly, the water cut is initially controlled by oil viscosity, but subsequently, by reservoir thickness through the analysis of oil and water production data. Thirdly, the bottom oil–water contact of the reservoir was re-corrected to build an accurate 3D geological model, based on the production history matching of a single well and the whole reservoir. Lastly, a scheme of thermal production coupled with cold production was proposed to exploit this special reservoir, and the parameters of steam, N2, and CO2 injection and production were optimized to predict oil production. This work can provide a valuable development model for the efficient exploitation of similar offshore special heavy oil reservoirs.

Effect of agricultural management system (“cash crop”, “livestock” and “climate optimized”) on nitrous oxide and ammonia emissions

AbstractThe study aimed to measure soil-atmosphere N2O fluxes and their controlling factors, as well as NH3 emissions and yields for two soils (silt loam and clay loam) in three management systems over two years under subsequent wheat and maize cultivation. The management systems were characterized as follows: (1) cash crop (C) with mineral fertilizer and conventional tillage; (2) livestock (L) with biogas residue fertilization and its incorporation prior to sowing in maize and reduced tillage; and (3) climate optimized (O) with minimum tillage, 8-year crop rotation, with biogas residue fertilization, in maize without incorporation in clay loam soil or incorporation by strip-tillage prior to seeding in silt loam soil. Stable isotope ratios of N2O and mineral N were determined to identify N2O processes. Within the organically fertilized maize treatments, cumulative N2O fluxes were highest in the O-system treatments of both sites (4.0 to 9.4 kg N ha− 1 a− 1), i.e. more than twice as high as in the L-system (1.5 to 3.1 kg N ha− 1 a− 1). Below root-strip till fertilizer application did not enhance N2O fluxes. Fluxes with mineral fertilization of wheat (1.1 to 3.1 kg N ha− 1 a− 1) were not different from those with organic fertilization. Isotopic values of emitted N2O revealed that bacterial denitrification dominated most of the peak flux events, while the N2O/(N2 + N2O) ratio of denitrification was mostly between 0.1 and 0.5. It can be concluded that, contrary to the intention to lower greenhouse gas fluxes by the O-system management, the highest N2O fluxes occurred in the O-system without biogas digestate incorporation in maize. With respect to NH3 fluxes, we could confirm that the application of digestate application in growing crops without incorporation or late incorporation in fertilization before sowing induces high fluxes. The beneficial aspects of the O-system including more stable soil structure and resource conservation, are thus potentially counteracted by increased N2O and NH3 emissions.

Pyrolytic hydrocarbon generation characteristics of the Chang 7 shale based on different experimental methods: Implications for shale oil and gas in the Ordos Basin

Shale oil and gas resources are abundant in the Chang 7 shale of the Yanchang Formation in Ordos Basin. To determine the characteristics and influencing factors of hydrocarbon generation evolution of the Chang 7 shale, a series of thermal simulation experiments were conducted on low‐maturity shale and kerogen samples. The results indicate that the maximum yield of shale oil are 294.5 and 304.3 mg/g TOC for kerogen sample at heating rates of 20 and 2°C/h, and the corresponding experimental temperatures are 360.2°C and 408.0°C, respectively. The utilization of lower heating rates is favourable for shale oil generation and it is recommended to employ a lower heating rate during in situ heating processes to maximize the economic benefits. The formation of crude oil cracking gas begins when simulating temperature exceeds 528.0°C (Easy Ro 2.6%) at a heating rate of 20°C/h and 480.0°C (Easy Ro 2.5%) at a heating rate of 2°C/h, as indicated by the carbon isotopic composition of gaseous hydrocarbons. The maximum oil production rate of the rock powder sample is 159.8 mg/g TOC, which is lower than that of the kerogen sample. It suggests that certain minerals in the Chang 7 shale may impede hydrocarbon generation. After the addition of pyrite, the highest yield of shale oil is 213.96 mg/g TOC, 33.9% higher than the yield of the original rock powder sample, reflecting the positive catalytic effect of pyrite on hydrocarbon generation of Chang 7 shale. Under geologic conditions, pyrite catalytic hydrocarbon generation may act primarily on the migration of organic matter by macromolecules, which considerably increases the probability of direct contact between pyrite and organic matter. Therefore, the organic‐rich shale with high pyrite content in Chang 7 member is the preferred target for in situ conversion of shale oil and gas in the Ordos Basin.

Maximum pitting corrosion depth prediction of buried pipeline based on theory-guided machine learning

Buried pipelines are crucial for the transportation of oil and natural gas resources. However, pipeline failure accidents have frequently occurred due to corrosion. Therefore, an accurate corrosion depth prediction model is necessary for the reliable supply of energy. In this paper, a theory-guided machine learning (ML) model is developed for maximum pitting corrosion depth prediction, the engineering theory and domain knowledge are integrated into feature space to improve the model interpretability. Firstly, several new feature variables are constructed based on the interactions between independent variables. Then, feature importance of all feature variables is obtained using random forest (RF). A hybrid multi-objective grey wolf optimization (HMOGWO) is proposed to optimize the hyper-parameters of RF model, considering feature number, prediction accuracy, and stability simultaneously. Finally, a comprehensive pitting corrosion dataset is utilized for performance evaluation. The results indicate that the proposed theory-guided model can achieve high prediction accuracy and stability, the optimal feature subset can be determined using multi-objective optimization method simultaneously, which solves the problems of model interpretability and feature selection for traditional ML models with the single-objective optimizer. This study is of great significance to the transportation safety of buried pipelines.

Characteristics and controlling factors of Lucaogou formation shale reservoir in the northern edge of Bogda Mountain, the Junggar Basin, China

The practice of oil and gas exploration has confirmed the existence of recoverable shale oil resources in the Permian Lucaogou Formation on the northern edge of the Bogda Mountains. However, previous research on the development characteristics and main controlling factors of shale oil resources in this area is relatively limited. In order to elucidate the development characteristics and principal controlling factors of the shale deposit in the Lucaogou Formation, the characteristics, physical properties, diagenesis, and influencing factors of the shale ore were investigated utilising data derived from outcrop, drilling, seismic, and geochemical analysis. The findings indicate that the shale of the Lucaogou Formation is prevalent and extensive. The deposit’s lithology is predominantly composed of dark grey and grey-black mud shale, interspersed with thin layers of dark grey and grey-black sandy mud shale and dolomite mud shale. The most prevalent minerals are carbonate minerals, followed by feldspar and quartz, with a notable proportion of brittle minerals. The deposit is primarily composed of dissolution pores, bedding fractures, and structural fractures, with a porosity of 1.23–3.26% and permeability of 0.012–0.076 mD, which are characteristic of ultra-low porosity and ultra-low permeability deposits. Among the three deposit types, the sandstone type exhibits the most favourable physical properties, followed by the dolomite type and the shale type, which displays the least favourable properties. The shale of the Lucaogou Formation is currently in the middle diagenetic phase, which is characterised by compaction, cementation (carbonate cementation, mudstone cementation, pebble cementation), and dissolution. The destructive effect of compaction and cementation on the physical properties is counterbalanced by the constructive effect of dissolution. The diagenetic environment has gradually changed from an alkaline environment to a slightly alkaline, slightly acidic stage.

Lithofacies assemblage and effects on diagenesis in lacustrine tight sandstone reservoirs: Samples from Upper Triassic Yanchang Formation, Ordos Basin, China

Lacustrine basins are rich in unconventional oil and gas resources and the heterogeneity of matrix reservoir quality seriously affects its development. Previous studies have recognized that diagenesis is the key factor affecting the heterogeneity of matrix reservoir quality, but diagenesis controlled by lithofacies assemblages is poorly studied. In this study, tight sandstones in the Triassic (Ladinian-Carnian) Chang 7 Member of Ordos Basin were taken as examples. Lithofacies, lithofacies assemblages, diagenesis evolution and distribution were investigated by casting thin section analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD), fluid inclusion and carbon-oxygen isotope. The results indicate that eight lithofacies assemblages in Chang 7 exhibit variations in lithofacies, sand-mud ratio and grain size rhythm, controlling the distribution and intensity of diagenesis. Variations in average proportion of lithofacies assemblages are linked to lake level cycles. Compared to cementation, the mechanical compaction has a higher adverse effect on primary porosity of tight sandstones in Chang 7. Siltstone lithofacies show stronger compaction and cementation (mainly clay cementation), whereas fine sandstone lithofacies exhibit stronger dissolution, especially FSpc (fine sandstone with parallel or cross-bedding). Modest proportions of illite (<4%) and chlorite (<1.5%) in fine sandstones tend to form clay coatings, resisting compaction and preserving more porosity. Conversely, abundant pore-filling illite (>4%) and chlorite (>1.5%) result in a noticeable decline in porosity. Particle size and sorting affect reservoir quality by controlling compaction strength. The origin of carbonate cement in sandstones is closely related to mud-rich lithofacies within lithofacies assemblages. Carbonate cementation preferentially occurs in fine sandstones within 0.4 m from the sand-mud interface and the thickness of adjacent mud-rich lithofacies is greater than 0.1 m. Interfaces between fine sandstones serve as fluid migration pathways and bidirectional erosion, facilitated by high porosity and feldspar content. In contrast, the clay-rich matrix in siltstones acts as a barrier hindering fluid migration, creating unidirectional erosion in fine sandstones near the interfaces between siltstones and fine sandstones. Ultimately, five evolution processes linking diagenesis with lithofacies assemblages are summarized, highlighting the differential reservoir quality. This study contributes to understanding the mechanism behind diagenetic variations in tight sandstones and the reservoir evaluation. Consequently, it offers geological reference for the development of unconventional oil and gas resources in comparable lacustrine basins.

Study of rock-breaking performance of V-axe-shaped PDC cutter in tight sandstone formation

In the field of oil and gas drilling engineering, tight sandstone strata are one of the strata that are difficult to drill. The V-axe-shaped cutter has a good effect in crushing tight sandstone strata. However, there were few studies on its specific structural parameters and rock-breaking performance in tight sandstone formations. To further explore its structural parameters and rock-breaking performance, this paper studies the rock-breaking performance of a V-axe-shaped PDC cutter in tight sandstone formation by combining experiments with finite element simulation. Mechanical tests show that the compressive strength is high, with values of 130.3 MPa, 223.3 MPa, and 271.6 MPa under confining pressures of 0/15/30 (MPa), respectively, with the condition of 0.02 mm/min loading rate. Rock lithology tests that the sandstone in this formation has strong abrasiveness. The penetration ability should be considered when evaluating the rock-breaking performance of cutting cutters. The results show that the V-axe-shaped PDC cutter mainly uses shear, extrusion, and point load to break rock together. It has a stronger ability and stability to attack the rock. With a 100° V-shaped angle (α) and 140° Axe-shaped angle(β) has the best rock-breaking property. The back-rake angle of the cutter can reduce cutter vibration and significantly improve PDC bit rock-breaking efficiency. The optimal rock-breaking back-rake angle of the V-axe-shaped cutter is 20° in dense sandstone formations. With the increase of wear height(0–3 mm), the synthetical mechanical specific energy (MSE) is reduced by 11.53%, 6.30%, 10.30%, and 33.28%, respectively, compared with the conventional cutter. The tests indicate that the rock-breaking efficiency of the V-axe-shaped PDC cutter is 12.9% higher than that of the conventional PDC cutter. The application of V-axe-shaped cutters on the bit is expected to improve the rock-breaking efficiency and footage of PDC bit in tight sandstone formations and realize the development of low-cost and high-benefit oil and gas resources.

Comparative Analysis between Remote Sensing Burned Area Products in Brazil: A Case Study in an Environmentally Unstable Watershed

Forest fires can profoundly impact the hydrological response of river basins, modifying vegetation characteristics and soil infiltration. This results in a significant increase in surface flow and channel runoff. In response to these effects, many researchers from different areas of earth sciences are committed to determining emergency measures to rehabilitate river basins, intending to restore their functions and minimize damage to soil resources. This study aims to analyze the mapping detection capacity of burned areas in a river basin in Brazil based on images acquired by AMAZÔNIA-1/WFI and the AQ1KM product. The effectiveness of the AMAZÔNIA-1 satellite in this regard is evaluated, given the importance of the subject and the relatively recent introduction of the satellite. The AQ1KM data were used to analyze statistical trends and spatial patterns in the area burned from 2003 to 2023. The U-Net architecture was used for training and classification of the burned area in AMAZÔNIA-1 images. An increasing trend in burned area was observed through the Mann–Kendall test map and Sen’s slope, with the months of the second semester showing a greater occurrence of burned areas. The NIR band was found to be the most sensitive spectral resource for detecting burned areas. The AMAZÔNIA-1 satellite demonstrated superior performance in estimating thematic accuracy, with a correlation of above 0.7 achieved in regression analyses using a 10 km grid cell resolution. The findings of this study have significant implications for the application of Brazilian remote sensing products in ecology, water resources, and river basin management and monitoring applications.

High Quality and Sustainable Development of Soil and water Conservation

Water and soil loss influences the soil and water resources of terrestrial ecosystem, ecological environment and ultimately the quality of life and high-quality development. China is the most serious soil erosion country in the world, especially in the Loess Plateau. After years of efforts, soil and water conservation in China has developed rapidly, and the surface runoff and soil loss in soil and water loss areas have decreased rapidly. However, with the increase in population and economic development, people’s living standards have been gradually improved, and higher requirements for soil and water conservation was put forward. However, the soil and water protection benefits cannot meet the needs of people’s good life for soil and water protection in the new era. In order to solve the problem; the high quality and sustainable management of soil and water conservation has been put forward. The results shows that the new and higher goal of soil and water conservation is to carry out the high quality and sustainable development of soil and water conservation, and obtain the maximum effect to meet the growing needs of people for soil and water protection and for a better life in the new era. The theoretical basis for high quality and sustainable development of soil and water conservation is the new theory of soil and water conservation. It includes that the soil and water loss is the process of transferring soil and water resources from one place to another; the impact of soil and water loss on the high-quality development of society includes positive and negative aspects; Soil and water conservation refer to use some methods or measures to reduce soil erosion to soil allowable loss. At the same time, make efficient use of the soil and water resources and minimize the loss of life and property; The high quality and sustainable management of soil and water conservation measures must be made to obtain the maximum effect and develop the economy and raise people’s income and meet the need of people’s requirements for soil and water conservation for a better life. The practice proof the theory is good.

Assessment of Soil-site Suitability for Major Horticulture Crops in Chikkumbi-3 Micro-watershed (4D7C5O2f), Karnataka Using Remote Sensing and GIS Techniques

Detailed soil resource inventorization was carried out at 1:7,920 scale in Chikkumbi-3 micro watershed, savadatti taluk, Belagavi district with an objective to assess the land suitability for various horticultural crops in the watershed. The soils of Chikkumbi-3 micro-watershed are characterized and classified into 3 soil series (CLK, CKB and HNL) comprising of 5 mapping units. The soil site characteristics and climatic factors were evaluated for its suitability for major horticultural crops viz., tomato, cabbage, chilli, rose, jasmine and coconut. The analysis revealed that the soil series CLK (Chulki), CKB (Chikkumbi), and HNL (Hanchinal) are presently not suitable for growing coconut due to significant limitations in physical conditions, rooting, and moisture. However, the region is deemed moderately to marginally suitable for the cultivation of tomato, cabbage, chilli, rose and jasmine. The main limitations in all the soil series found to be texture, CaCO3 content and climatic factors. These findings serve as foundational data for identifying specific soil constraints, aiding in the development of sustainable strategies for crop production in the study area.

Soil footprint: A simple indicator to communicate and quantify soil security

Soil erosion is a major threat to soil security, and therefore to agriculture. To address this challenge, effective strategies are needed to protect soil resources without compromising crop yields. Currently, there are three main players involved: scientists, policymakers, and land managers. However, the technical knowledge required to understand how soil erosion affects food production hinders the communication of the potential benefits of soil sustainability strategies to nontechnical stakeholders, such as farmers and food producers. Moreover, a major player in this fight is still missing, consumers. If there is no connection between soil and society then the soil itself may not be valued and it is less likely to be managed sustainably. In this study, we propose the concept of soil footprint, defined as the ratio of soil loss to crop yield, to communicate, quantify, and compare soil security for different crops. It is a versatile concept that can be applied for a multitude of potential practical uses. To showcase some of these potential uses, we used national data to calculate the soil footprint of the ten main crops in Spain. We demonstrate the utility of this metric to compare and rank crops, identify problematic regions, and assess the effect of land management on the soil footprint. The soil footprint indicator offers advantages in terms of simplicity, facilitating easy calculation, comparison, and interpretation by non-technical users. This can engage society in soil conservation, empower land managers to define sustainable soil management strategies, and promote policies to enhance soil security.

Spatial Prediction and Influencing Factors Analysis of Soil Salinization in Coastal Area Based on MGWR

Quantitative analysis of the spatial non-stationary characteristics of soil salinization influencing factors and the prediction of its spatial distribution are of great significance for the rational use of coastal saline soil resources and the formulation of local prevention and control measures. In this study, the Hekou District of Dongying City, Shandong Province, was used as the study area, and the descriptive statistics of soil salinization status were conducted using classical statistical methods. Spatial autocorrelation theory was used to explore the characteristics of global and local spatial structure of soil salinization in the study area. Influential factors related to soil salinity were selected, and multivariate linear regression （MLR）, geographically weighted regression （GWR）, and multi-scale geographically weighted regression （MGWR） methods were used to model and predict the spatial distribution of soil salinity in the study area and to analyze the spatial heterogeneity of the effects of different influencing factors on soil salinity. The results showed that： ① The mean value of soil salinity in the study area was 5.84 g·kg-1, indicating severe salinization, with a global Moran's I index of 0.19 （P<0.00） and obvious spatial aggregation characteristics. ② Among the three models, the MGWR model had the highest modeling accuracy. Compared with that of the MLR model, the Radj2 of GWR and MGWR improved by 0.05 and 0.07, respectively, and the RSS decreased by 210.13 and 179.95, respectively. ③ The results of MGWR regression showed that the spatial distribution of soil salinity appeared to be mainly affected by the middle soil salinity, soil clay content, and vegetation cover from the mean values of standardized regression coefficients of different influencing factors. Different influencing factors had significant spatial non-stationary characteristics on soil salinization. ④ The results of the spatial distribution prediction of soil salinity in MGWR showed that the areas of high soil salinity （≥6 g·kg-1） were mainly distributed in the northern part of the study area, with an overall spatial trend of decreasing from the coast to the interior. The results of the study can be used as a reference for the analysis and predictive mapping of factors affecting soil salinization in the county and on a larger scale using MGWR.

Simulated Lunar Soil: Can It Be Organically Modified through Compost Cultivation?

This study aimed to explore the possibility of improving the fertility of lunar soil through the reuse of resources by composting household waste and collecting composting fermentation broth. The fermentation broth was used to culture a simulated lunar soil at different concentration gradients for 30 days under aerobic and anaerobic conditions. Microbial biomass carbon and nitrogen content, typical mineral elements, and the microbial community were tested to determine whether the fertility of the lunar soil had improved. Results showed that the microorganisms in the simulated lunar soil samples successfully adhered and grew under both aerobic and anaerobic experimental conditions. The simulated lunar soil samples cultured in the anaerobic environment outperformed those in the aerobic environment regarding microbial biomass growth and water-soluble mineral elements. The study results create opportunities for the future reuse of domestic garbage on the lunar base, providing a technical basis for the in situ reuse of lunar soil resources for plant cultivation.

Heterogeneity of Organoclay Complexes in Shale Regulates the Generation of Shale Oil.

Organic matter (OM) and clay minerals are important components in shale, which are intimately associated with each other in the form of organoclay complexes. The diverse mineral-OM associations result in varying OM occurrences, which possess distinct hydrocarbon generation potential and ultimately affect the accumulation of shale oil. Therefore, the investigation of the heterogeneity of organoclay complexes is crucial to gaining a comprehensive understanding of the varying exploration potential of shale oil resources. In the present study, shale samples from three intervals in Dongying Depression were collected to investigate the mineralogical and organic characteristics of the organoclay complexes, aiming to explore their impact on the yield and composition of shale oil. Results showed that the smectite gradually converted into illite, which was accompanied by the release of OM from clay mineral interlayers and the desorption of chemically adsorbed OM. The yield and composition of shale oil cannot solely be explained by the OM content and types in the shale. Instead, they are intricately linked to the evolution of minerals and OM occurrence. From the perspective of the heterogeneity of organoclay complexes, despite the abundant OM content in shallower intervals (Es3x), the shale oil formation remains limited due to the low degree of mineral evolution and the stabilization of the adsorbed OM by clay minerals. Consequently, this leads to a higher proportion of resin, which is not conducive to the mobility of shale oil. In contrast, despite the OM content varying slightly in the deeper interval (Es4s), the elevated smectite illitization degree promotes the desorption of OM and its conversion into hydrocarbons. This results in a substantial increase in shale oil formation and a higher proportion of saturates, greatly enhancing the mobility of shale oil. These findings are profoundly significant for understanding shale oil generation and accumulation.

Numerical Simulation of Rock Vibration Response under Ultrasonic High-Frequency Vibration with High Confining Pressure

As deep oil and gas resources and Carbon Capture and Storage (CCS) are developed, enhancing drilling efficiency in hard rock formations has emerged as a critical technology in oil and gas extraction. The advancement of ultrasonic, high-frequency vibration rock-breaking technology significantly facilitates efficient rock crushing. When subjected to ultrasonic high-frequency vibrations, the rock’s response is a crucial issue in implementing ultrasonic vibration rock crushing technology. This study employed numerical simulation and theoretical deduction methods, utilizing a multi-physics approach that couples solid mechanics with pressure acoustics. It integrated information on common influencing parameters of ultrasonic generators and reservoir rock properties to establish model parameters, analyze simulation results, and perform theoretical deductions. The research investigated the response patterns of different-sized rock samples under high-frequency ultrasound vibration excitation across various frequencies, amplitudes, and confining pressure conditions. Through the development of a three-dimensional model and the application of principles from solid mechanics and elastoplasticity, the study derived equations that describe the resonance frequencies of rock blocks under confining pressure as functions of relevant rock parameters. The findings indicate that ultrasonic vibrations can effectively induce rock displacement. Under excitation frequency sources, the rock exhibits a natural frequency correlated with the rock sample size. When the excitation frequency approximates the natural frequency, the rock resonates. At this point, the rock’s surface displacement is maximal. The rock undergoes tensile stress, leading to stress concentration that facilitates rock damage and fragmentation. Increasing the excitation amplitude enhances rock crushing, as it amplifies the maximum surface displacement under the same frequency excitation. Confining pressure exerts an inhibitory effect on the rock’s vibration response, but it does not alter the resonance frequency of the rock sample, a fact verified by both numerical simulation and theoretical results. Based on the research findings in this paper, it can help to optimize the parameters of ultrasonic vibration rock breaking in field application to achieve the best rock-breaking effect.