Soil Structure Research Articles

Model experimental study on the mechanism of collapse induced by leakage of underground pipeline

The evolution and mechanism of ground collapse caused by underground water pipeline leakage have become increasingly significant as more urban areas experience collapses. Based on the principle of similarity, and considering the engineering context of road collapses in Anqing City, Anhui Province, this study designed a 3 m × 2 m × 2 m rupture-collapse model test device. Digital Image Correlation (DIC) technology was employed to investigate the erosion process and collapse mechanisms caused by underground pipeline leakage. The results indicate that groundwater seepage provides the driving force for collapses, combined with the migration space provided by defects, collectively triggering the collapses. When groundwater seepage is minimal, the cohesive forces between soil particles maintain soil stability. As groundwater seepage increases, the soil particle framework is eroded, leading to soil structure destabilization and collapse initiation. The depth of collapse significantly influences stress evolution: stress evolution intensity beneath and above the collapse pit is positively correlated with the distance from the collapse pit bottom, but negatively correlated with the distance from the defect. The research provides insights for the early warning and management of ground collapse.

The Role of Plant-Mycorrhizal-Fungal Interactions in Soil Health and Carbon Sequestration in Agroecosystems

Abstract: Understanding the intricate interactions between plants, mycorrhizal fungi, and soil health is crucial for sustainable agriculture and climate change mitigation. This review synthesizes current research to elucidate the multifaceted role of plantmycorrhizal-fungal interactions in soil health and carbon sequestration in agroecosystems. A meta-analysis of 75 studies spanning diverse ecosystems and plant species reveals a significant positive correlation between mycorrhizal colonization and soil organic carbon content, with an average increase of 25% compared to non-mycorrhizal systems. Furthermore, mycorrhizal symbiosis enhances soil structure and aggregation, promoting water retention and nutrient cycling, which are essential for maintaining soil fertility and resilience to environmental stressors. The contributions of different mycorrhizal types (arbuscular, ectomycorrhizal, and ericoid) to soil carbon dynamics are also examined, highlighting their unique roles in carbon allocation and stabilization. Additionally, the review discusses the potential implications of plant-mycorrhizal-fungal interactions for mitigating greenhouse gas emissions through enhanced carbon sequestration in agricultural soils. Insights into the mechanisms underlying these interactions, including mycorrhizal-mediated changes in root exudates, microbial communities, and soil enzymatic activities, are discussed. Overall, this review underscores the importance of integrating mycorrhizal symbiosis into agroecosystem management practices to enhance soil health, carbon sequestration, and climate resilience.

Seismic response of jacket-supported offshore wind turbines for different operational modes considering earthquake directionality

This study aims to analyse how jacket-supported OWTs functioning in three different operational modes (power production, emergency shutdown and parked mode) respond to seismic actions when subject to different incoming wind directions and ground motion shaking directions. To do so, the seismic response of the NREL 5MW OWT founded on the OC4 jacket substructure is simulated using an OpenFAST model that includes multi-support seismic input, soil–structure interaction and kinematic interaction. The impact of the working conditions and of the directionality of the loads on the jacket substructure is analysed and discussed. The tower top accelerations and displacements are examined for different sets of cases, and the seismic response of the jacket is studied in terms of internal forces and von Mises stresses along the different levels of the substructure. The results show, and quantify, the relevance of considering the different operational modes for a correct design of the substructure and of the foundation. The maximum structural stresses within the jacket substructure appear almost always in power production, with the exception of the top part of the legs, where higher stresses arise during emergency shutdown in several cases.

Phosphorus addition stimulates overall carbon acquisition enzymes but suppresses overall phosphorus acquisition enzymes: A global meta-analysis

Of the total land worldwide, 43 % is phosphorus (P)-constrained, which is significantly greater than the proportion of nitrogen-constrained land (18 %). However, there are some uncertainties regarding the responses of enzyme activities to P addition on a global scale. We collected data from 99 publications and performed a meta-analysis to assess the responses of 11 extracellular enzymes, including carbon, nitrogen, and phosphorus acquisition enzymes, and oxidases. P addition significantly increased the activities of β-1, 4-glucosidase, sucrase, cellobiohydrolase, and alkaline phosphatase, while lowering the activities of acid phosphatase and phosphodiesterase. The responses of enzyme activities to P addition differed considerably across the three ecosystems (forest, grassland, and cropland). P addition significantly decreased the activities of acid phosphatase, phosphodiesterase, and P-acquisition enzymes in forests, but increased the activities of leucine aminopeptidase, carbon acquisition enzymes, and nitrogen acquisition enzymes in grasslands. Sucrase, β-1,4-glucosidase, N-acetyl-β-glucosaminidase, alkaline phosphatase, and carbon acquisition enzymes were significantly stimulated in croplands. In addition, all P addition rates significantly increased the activity of alkaline phosphatase, a P-acquisition enzyme, in croplands. Ca(H2PO4)2 had a greater effect on enzyme activity than other fertilizer types, possibly because Ca2+ can improve the soil structure and enhance microbial metabolic activities. Furthermore, structural equation models revealed that mean annual precipitation and ecosystem type had significant impacts on the response of P-acquisition enzymes, but no factor could directly influence the response of carbon-acquisition enzymes. Our investigation of enzyme activities in response to P addition complements the biogeochemical model and helps forecast soil nutrient dynamics. We propose that rather than focusing on a single factor, P fertilizer addition programs should take into account the effects of mean annual precipitation, ecosystem type, and nutrient interactions, which could also reduce P pollution.

Impact of soil sterilization on antagonistic efficiency against tobacco mosaic virus and the rhizosphere bacterial community in Nicotiana benthamiana

Soil microorganisms play a critical role in influencing plant growth and managing soil pathogens. Tobacco mosaic virus (TMV) induces significant economic losses in global agriculture and can impact the composition and function of soil microbial communities. Despite its importance, the interactions between viruses and soil microbial communities remain inadequately understood. In this study, we employed 16S rRNA gene sequencing coupled with bioinformatics analyses to thoroughly investigate the bacterial communities and physicochemical properties of the rhizosphere soils of healthy tobacco plants under both sterilized (WJ) and non-sterilized (YJ) conditions, as well as TMV-infected tobacco plants under both sterilized (WT) and non-sterilized (YT) conditions. Our findings demonstrated that TMV infection significantly modifies the physicochemical properties and bacterial community structure of rhizosphere soils, with these changes being more pronounced in non-sterilized soils. Moreover, the YT samples exhibited a more intricate network of bacterial interactions. They showed significant differences from WT samples in key bacterial genera that might be involved in the response to or antagonism of TMV. The genera Burkholderia-Caballeronia-Paraburkholderia and Dyella were highlighted. These results suggest that rhizosphere microorganisms actively respond to TMV infection, with a more pronounced response observed in non-sterilized soils. This study provides novel insights into the microbial dynamics associated with TMV infection and underscores the importance of soil microbial communities in plant health and disease resistance. Additionally, it offers an experimental framework for future research on soil-borne diseases, emphasizing the pivotal role of soil microbiota in disease ecology and soil impact.

Effects of Prolonged High Salinity Stress on Alfalfa (Medicago sativa L.) Cultivars and Populations

Background: Alfalfa is a promising crop for improving soil structure and restoring agricultural land, particularly in areas affected by salinity. However, high and continuing salinity in soil and irrigation water can pose a significant challenge to the growth and productivity of alfalfa. The objective of this study was to investigate the effects of prolonged high salinity stress on alfalfa cultivars and populations. Methods: The material used in this study included 16 alfalfa populations and four alfalfa cultivars that exhibit salt tolerance during germination and early seedling development. The materials were exposed to 17.52 dS m-1 saline irrigation water stress for three months. As well as the morphology, survival at three months and crude ash, sodium and chloride ions were measured. Result: Salt-tolerant plants showed a slowdown in growth compared to control conditions, although they were still able to maintain growth. Duration and severity of stress affected the salt tolerance of the genotypes. The survival rates of the materials remained relatively unchanged for the first two months, but decreased significantly by the end of the third month. Furthermore, the survival rate of the materials increased as the amount of sodium and chloride ions absorbed by the plant decreased under high salinity conditions. Genetic material demonstrating long-term high salinity tolerance is crucial for resistance breeding and holds promise for the development of tolerant cultivars that can be grown under field conditions in the future. The properties of this material need to be determined and its long-term performance in field conditions needs to be tested.

Spatial distribution of PAHs and microbial communities in intertidal sediments of the Pearl River Estuary, South China

The exploration of sediment pollution caused by PAHs and its impact on microbial communities can provide valuable insights for the remediation of sediments. The spatial distribution of PAHs and their impact on the microbial community within the Pearl River Estuary were investigated in this study. The findings revealed that the total concentration ranges of 16 PAHs were between 24.26 and 3075.93 ng/g, with naphthalene, fluorene, and phenanthrene potentially exerting adverse biological effects. More PAHs were found to accumulate in subsurface sediments, and their average accumulation rates gradually decreased as the number of rings in PAHs increased, ranging from 180 % for 2-ring to 36 % for 6-ring. The phyla Proteobacteria, Bacteroidetes, Actinobacteria, and Chloroflexi were found to dominate both surface and subsurface sediments The correlation between microbial genera and PAHs contents was weak in sediments with low levels of PAHs contamination, while a more significant positive relationship was observed in sediments with high levels of PAHs contamination. The physicochemical properties of sediments, such as pH, soil structure and Cu significantly influence bacterial community composition in highly contaminated sediments. Additionally, the network analysis revealed that certain bacterial genera, including Novosphingobium, Robiginitalea and Synechococcus_CC9902, played a pivotal role in the degradation of PAHs. These findings are significant in comprehending the correlation between bacterial communities and environmental factors in intertidal ecosystems, and establish a scientific foundation for bioremediation of intertidal zones.

Vermicompost Effects on Soil Chemistry and Biology: Correlations with Basil's (Ocimum basilicum L.) Total Phenolic Content and Phenological Traits

This study explores the effects of vermicompost on the chemical and biological properties of soils, their nutrient content, and the impact on the growth and phenolic content of basil (Ocimum basilicum L.). Using a controlled experimental setup, we tested five dosages of vermicompost (0%, 4%, 12%, 20%, and 24%) to evaluate their influence on soil biological activity by measuring basal respiration (CO2-C), microbial biomass C (MBC-C), and dehydrogenase enzyme activity (DHA) as well as on basil's growth parameters and total phenolic content (TPC). The results show that vermicompost addition to soil enhanced soil microbial activity in direct proportion to the dose of vermicompost. The application of lower dosages of vermicompost (4% and 12%) significantly enhanced both fresh and dry weights, suggesting an improvement in nutrient uptake and soil structure, which likely facilitated better root growth and nutrient absorption. However, higher dosages (20% and 24%) were associated with reduced growth metrics, likely due to nutrient overload or salt stress. Notably, the highest vermicompost concentration (24%) led to a substantial increase in total phenolic content (TPC) in basil leaves, correlating with decreased growth metrics. This response indicates the plant's defensive mechanism against oxidative stress caused by excess nutrients or salinity from the vermicompost. A multiple regression analysis following a correlation analysis also revealed an inversely proportional relationship between phosphorus content in the soil and total phenolic content in basil leaves. Our findings illustrate that while moderate vermicompost dosages optimize plant growth and health, higher concentrations can strategically enhance phenolic content due to nutrient overload or salt-induced stress. These results offer critical insights for tailoring organic amendment applications to balance plant growth and biochemical properties in agricultural practices.

Characteristics of microplastics and their abundance impacts on microbial structure and function in agricultural soils of remote areas in west China

As an emergent pollutant, microplastics (MPs) are becoming prevalent in the soil environment. However, the characteristics of MPs and the response of microbial communities to the abundance of MPs in agricultural soils in West China still need to be elucidated in detail. This study utilized the Agilent 8700 Laser Direct Infrared (LDIR) to analyze the characteristics of small-sized MPs (20–1000 μm) in soils from un-mulched and mulched agricultural fields in West China, and illustrated their correlation with microbial diversity. The results revealed a higher abundance of MPs in mulched soil ((4.12 ± 2.13) × 105 items kg−1) than that in un-mulched soil ((1.04 ± 0.26) × 105 items kg−1). The detected MPs were dominated by fragments, 20–50 μm and Polyamide (PA). High-throughput sequencing analysis indicated that alpha diversity (Chao1 and Shannon indices) in the plastisphere was lower compared to that in soil, and varied significantly with MPs abundance in soil. As the abundance of MPs increased, the proportion of soil about the degradation of organic matte and photoautotrophic taxa increased, which showed enrichment in the plastisphere. Functional predictions further indicated that MPs abundance affected potential soil functions, such as metabolic pathways associated with the C and N cycling. The plastisphere showed higher functional abundance associated with organic matter degradation, indicating higher potential health risks compared to soil environments. Based on the RDA analyses, it was determined that environmental physicochemical properties and MPs abundance had a greater impact on fungal communities than on bacterial communities. In general, the abundance of MPs affected the microbial diversity composition and potentially influenced the overall performance of soil ecosystems. This study offers empirical data on the abundance of MPs in long-term mulched agricultural fields and new insights for exploring the ecological risk issues associated with MPs.

A method for estimating the bulk density and particle density of granite residual soil based on the construction of pedotransfer functions

AbstractParticle density (ρs) and bulk density (ρb) are key factors in the calculation of total soil porosity. However, direct measurements of ρs and ρb are labour‐intensive, time‐consuming, and sometimes impractical. Pedotransfer functions (PTFs) provide alternative methods for indirect estimation of ρs and ρb. In this paper, the accuracy of typical 12 ρs and 9 ρb PTFs was evaluated using easily measurable soil properties (sand, silt, clay, and soil organic matter (SOM) content) from granitic residual soils collected from six study areas in subtropical China, and the accuracy of PTFs constructed based on multiple linear stepwise regression (MSR) and machine‐learned algorithms (backpropagation neural network, k‐nearest neighbour algorithms, random forests, support vector machines, and gradient boosted decision trees) was compared to determine the accuracy of PTFs. The results show that typical PTFs have poor accuracy (R2adjusted < 0.020) and are not applicable to the indirect estimation of ρs and ρb in granitic residual soils. The PTFs constructed by machine learning algorithms all performed better than MSR, with the highest estimation accuracy of the PTFs constructed by the random forest algorithm, with R2adjusted values of 0.923 and 0.933 for the ρs and ρb PTFs, respectively, and root‐mean‐square error of 0.020 g·cm−3 and 0.023 g·cm−3, respectively. Compared with MSR, the random forest algorithm has greater accuracy and eliminates the restriction of PTFs on predictors, which provides support for understanding the changing rules of ρs and ρb in granite residual soils in subtropical regions, evaluating soil quality and improving soil structure.

Gambaran Kesiapsiagaan Warga dalam Menghadapi Bencana Tanah Longsor di Dukuh Gesikan Desa Jrakah Selo Boyolali

Landslides are geological disasters that can cause fatalities and large material losses, caused by uneven and unstable soil structures. Objective: To obtain an overview of residents' preparedness in facing landslides in Dukuh Gesikan, Jrakah Selo Boyolali Village. Method: This research uses a descriptive survey method with a sample size of 76 respondents and uses a stratifiet random sampling technique. Results: The results showed that based on the characteristics of the respondents, the majority were in the age range 26-45 years (48.7%), male (56.6%), junior high school education (44.7%). The general results showed that the preparedness of the residents of Dukuh Gesikan, Jrakah Selo Boyolali Village was in the "Almost ready" category. This is shown in the preparedness indicators, it is known that the level of knowledge is very ready (84.2%), emergency response plans are ready (44.7%), policies are almost ready (47.4%), resource mobilization is less ready (51.3% ), less prepared disaster warnings (46.1%). Conclusion: The description of residents' preparedness in facing landslides in Dukuh Gesikan, Jrakah Selo Boyolali Village is in the almost ready category with the preparedness index results obtained at (46.1%).

A comparative analysis of soil organic carbon stock and soil aggregation in two crop sequences in the Rolling Pampa (Argentina)

Understanding how farming practices affect soil organic carbon (SOC) accumulation is essential for sustainable agriculture. Agronomic decisions, such as crop sequence, significantly influence various soil properties. However, the overall benefits of crop rotation on soil structure and SOC storage remain uncertain. We compared the effects of soybean (Glycine max L.) monocropping with a three-year crop rotation comprising wheat (Triticum aestivum L.)/soybean double crop, maize (Zea mays L.), and soybean on the vertical distribution of SOC up to one metre depth. Additionally, we examined carbon accumulation as particulate organic matter-carbon (POM-C), soil aggregation, and structural stability in the topsoil. Compared to monocropping, crop rotation increased SOC concentrations (19 vs. 16 gC kg soil⁻¹), stock (12 vs. 10.7 MgC ha⁻¹), and POM-C content (6 vs. 3.2 gC kg soil⁻¹) in the first 5 cm of soil. At 20–65 cm depth, rotation showed a marginal increment of SOC stock with respect to soybean monocropping. The increased surface SOC content in the rotation positively affected the POM-C content and macro-aggregation. However, soil structural stability showed a tendency to be higher in the monocropping, especially at a depth of 5–20 cm. Overall, crop rotation demonstrated potential for enhanced carbon sequestration in temperate agroecosystems within three years, despite not significantly improving soil structural stability.

Heavy Metal Uptake and Hyperaccumulation in Some Wild Plant Species Köyceğiz Special Environmental Protection Area Located Around Old Chrome Mineral Deposits

In this study, the possible presence of heavy metals in the soil and wild plant species around the old Cr deposits of Köyceğiz-Dalyan Special Environmental Protection Area (Sandras Mountain) was investigated. Possible anthropogenic risk factors to which wild plant biodiversity is exposed are also the subject of this research. Fe, Cd, Co, Cr, Ni and Pb contents of soil, shoot and root samples of five wild plant species growing naturally in the region in question were investigated. These five species are: Alyssum masmenaeum (AM), Cytisopsis pseudocytisus (CP), Centaurea ensiformis (CE), Fumana aciphylla (FA), Phlomis angustissima (PA). The data obtained showed that heavy metals other than Ni, Cr and Co were found within normal limits in the soil samples. Particularly, soil Ni content is extremely high. Heavy metals except Ni, Cr and Fe were found within normal limits in shoot and root samples. One species (AM) for Ni and three species (FA, PA and CE) for Fe showed distinct hyperaccumulator properties. Ni hyperaccumulation detected in the Alyssum masmenaeum species is a particularly striking but well-known phenomenon. Since the research area has special environmental protection status, the soil structure and endemism of the region must be absolutely protected.

THE EFFECT OF OIL PALM EMPTY FRUIT BUNCH BIOCHAR AND CHICKEN MANURE BIOCHAR ON NUTRIENT UPTAKE OF N, P, K AND YIELD OF SWEET CORN ON ALLUVIAL LAND

Alluvial land which is very wide in the West Kalimantan region can be used as land for the cultivation of sweet corn. Low organic matter in alluvial soils requires fixing agents to improve soil structure. This study aims to determine the effect of giving a combination of tankos biochar and chicken manure biochar on dry weight, nutrient uptake of N, P, K and weight of cobs with sweet corn husks. This research was conducted from November to April, in the experimental garden of the Faculty of Agriculture, Tanjungpura University, Pontianak City, West Kalimantan. This study used a completely randomized design (CRD) consisting of 5 treatments and 5 replications consisting of 25% tankos biochar and 75% chicken manure biochar: B0 (Control), B1 (20 tonnes/ha), B2 (40 tonnes/ ha), B3 (60 tonnes/ha), B4 (80 tonnes/ha). The results showed that the administration of a combination of tankos biochar and chicken manure biochar had a significant effect on all parameters. Giving a combination of tankos biochar and chicken manure biochar. Giving a combination of tankos biochar and chicken manure biochar had a very significant effect on the parameters of dry weight and weight of corn cobs and husks. The best treatment or dosage for all parameters lies in treatment B4 (80 tons/ha) which gives a 3.7% increase in dry weight, N absorption is 1.3%, P absorption is 1.45%, K absorption is 0.25% , the weight of cobs with husks was 1.88% % and the yield of sweet corn was 10.40 tonnes/ha.

No-tillage with straw retention influenced maize root growth morphology by changing soil physical properties and aggregate structure in Northeast China: A ten-year field experiment

Conservation tillage, particularly the implementation of no-tillage and straw retention (NTS), has been proposed as an effective practice to enhance soil structure and improve soil quality in Northeast China. However, the impact of NTS on maize (Zea mays L.) root growth morphology and the influence of tillage practices on maize root morphology through soil physical properties and structure in Northeast China remain understudied. To address this knowledge gap, a continuous ten-year experiment was conducted to assess the effects of NTS on soil physical properties, aggregate structure, maize root morphology, and their interconnections. Our findings demonstrate that the NTS treatment significantly increased soil water content and soil bulk density at depths of 0–5 cm (1.6%) and 5–10 cm (2.2%), while decreasing soil porosity at depths of 0–5 cm (1.4%) and 5–10 cm (2.0%) compared to conventional tillage (CT). Additionally, NTS resulted in a higher content of soil macro-aggregates (> 0.25 mm) and improved soil aggregate stability compared to CT. Notably, root length, root surface area, root volume, and root biomass in the NTS treatment were 6.04%, 22.15%, 10.04%, and 9.29% higher than those in CT, respectively. However, there was no significant difference in root diameter between the two tillage practices. These results reveal that NTS induces alterations in soil physical properties, aggregate size distribution and aggregate stability, thereby affecting maize root growth morphology.

Design of the System of an Assemblable Channel Slope Weeder

If the grass roots of the water conveyance channel slope dig into the soil, it may cause the soil structure to loosen, and then increase the risk of slope landslide. The operation of manual cleaning weeds is dangerous due to the large slope of the channel. In this context, the design of a channel slope weeder that can adapt to different slopes is very important for the protection of the water channel slope. The weeder concept vehicle designed in this paper is mainly composed of four parts: drive car, frame mechanism, track mechanism and weeder mechanism. At the same time, the structure is analyzed by finite element method, and the stability and safety are analyzed by strength. The reference is provided for the design of the algal removal vehicle on the channel slope.

Miscanthus sp. root exudate alters rhizosphere microbial community to drive soil aggregation for heavy metal immobilization

The heavy metals (HMs) spatial distribution in soil is intricately shaped by aggregation processes involving chemical reactions and biological activities, which modulate HMs toxicity, migration, and accumulation. Pioneer plants play a central role in preventing HMs at source, yet the precise mechanisms underlying their involvement in soil aggregation remain unclear. This study investigates HMs distribution within rhizosphere and bulk soil aggregates of Miscanthus sp. grown in tailings to elucidate the impact of root exudates (REs) and rhizosphere microbes. The results indicate that Miscanthus sp. enhance soil stability, increasing the proportion of macroaggregates by 4.06 %–9.78 %. HMs tend to concentrate in coarse-aggregates, particularly within rhizosphere environments, while diminishing in fine-aggregates. Under HMs stress, lipids and lipid-like molecules are the most abundant REs produced by Miscanthus sp., accounting for under up to 26.74 %. These REs form complex with HMs, promoting microaggregates formation. Charged components such as sugars and amino acids further contribute to soil aggregation. REs also regulates rhizosphere bacteria and fungi, with Acidobacteriota, Chloroflexi were the dominant bacterial phyla, while Ascomycota and Basidiomycota dominate the fungal community. The synergistic effect of REs and microorganisms impact soil organic matter and nutrient content, facilitating HMs nanoparticle heteroaggregation and macroaggregates formation. Consequently, soil structure and REs shape the distribution of HMs in soil aggregation. Pioneer plants mediate REs interaction with rhizosphere microbes, promoting the distribution of HMs into macroaggregates, leading to immobilization. This study sheds light on the role of pioneer plants in regulating soil HMs, offering valuable insights for soil remediation strategies.

Variations in soil erodibility (K-factor) for the Chernozems depending on the method of texture determination

Soil erodibility (K-factor) is an important parameter in erosion modeling, is one of five factors of the Revised Universal Soil Loss Equation (RUSLE), and generally represents the soil's response to rainfall and run-off erosivity. The erodibility could be determined based on direct measurements of soil properties and mathematical calculations. In this study, the K-factor was calculated based on a formula from RUSLE, proposed by Renard et al. (1997). All input parameters: soil organic carbon (SOC), soil structure, and permeability classes were measured by one method, but particle size distribution – in two ways by sedimentation and laser diffraction methods to assess the impact the K-factor variability and the values of soil erosion rates. The 107 soil samples of Chernozems from Kursk Oblast (Russia) were studied. The texture for the most of samples was classified as silty loam in both analyses. However, the laser diffraction underestimates the clay content by an average of 13.2% compared to the pipette method. The average K-factor estimated based on laser diffraction data was 0.050, and 0.034 t ha h ha−1 MJ−1 mm−1 – sedimentation method. Thus, depending on the method of soil texture analysis, the RUSLE calculated soil loss could underestimated/overstated by 32% (or 4 t ha-1 yr-1 on average in the study site). Therefore, we propose a regression equation-based conversion method of laser diffraction data to sedimentation method data for Chernozems.The Laska-TM laser analyzer measured on ∼ 13% less clay fraction (more on ∼ 8% silt and ∼ 5% fine sand) compared with sedimentation method data.For erosional researchers/modelers it is suggested to state the method of soil texture analysis (based on sedimentation law or laser diffraction) was used for RUSLE K-factor calculations.To convert K-factor values (for Chernozems) calculated and based on data of the sedimentation method to laser sedimentation – it suggested utilize the coefficient 1.47 (0.68 – vice versa).

Current Status and the Role of Biofilm Biofertilizer for Improving the Soil Health and Agronomic Efficiency of Maize on Marginal Soil

The use of biofilm biofertilizers is emerging as a promising strategy to improve soil health and agronomic efficiency, especially for maize production on marginal soils. This review focuses on the current status and critical role of biofilm biofertilizers in improving soil properties and maize productivity. This study used Preferred Reporting Items for Systematic Reviews and Meta-Analyses using Scopus and ScienceDirect databases from 2014-2024. Results showed that current status of biofilm biofertilizer utilization is spread on azolla, rhizobacteria, and endophytic bacteria species. Biofilm biofertilizers are beneficial microbial communities encapsulated in extracellular polymeric substances (EPS) that contribute to soil structure stabilization, nutrient solubilization and improved water retention. Application of these biofertilizers has been shown to improve soil fertility by increasing organic matter content, promoting nutrient cycling, and stimulating microbial activity. These improvements result in better root development, higher plant growth rates and increased crop yields. Especially on marginal soils, where nutrient availability and soil structure are often compromised, biofilm biofertilizers offer a sustainable solution to mitigate these limitations. This review synthesizes findings from recent studies and highlights the mechanisms by which biofilm biofertilizers exert their beneficial effects, thereby highlighting their potential in sustainable agricultural practices for maize production on suboptimal soils.

A method for evaluating the effects of gentle remediation options (GRO) on soil health: Demonstration at a DDX-contaminated tree nursery in Sweden

Healthy soils provide valuable ecosystem services (ES), but soil contamination can inhibit essential soil functions (SF) and pose risks to human health and the environment. A key advantage of using gentle remediation options (GRO) is the potential for multifunctionality: to both manage risks and improve soil functionality. In this study, an accessible, scientific method for soil health assessment directed towards practitioners and decision-makers in contaminated land management was developed and demonstrated for a field experiment at a DDX-contaminated tree nursery site in Sweden to evaluate the relative effects of GRO on soil health (i.e., the ‘current capacity’ to provide ES). For the set of relevant soil quality indicators (SQI) selected using a simplified logical sieve, GRO treatment was observed to have highly significant effects on many SQI according to statistical analysis due to the strong influence of biochar amendment on the sandy soil and positive effects of nitrogen-fixing leguminous plants. The SQI were grouped within five SF and the relative effects on soil health were evaluated compared to a reference state (experimental control) by calculating quantitative treated-SF indices. Multiple GRO treatments are shown to have statistically significant positive effects on many SF, including pollutant attenuation and degradation, water cycling and storage, nutrient cycling and provisioning, and soil structure and maintenance. The SF were in turn linked to soil-based ES to calculate treated-ES indices and an overall soil health index (SHI), which can provide simplified yet valuable information to decision-makers regarding the effectiveness of GRO. The experimental GRO treatment of the legume mix with biochar amendment and grass mix with biochar amendment are shown to result in statistically significant improvements to soil health, with overall SHI values of 141 % and 128 %, respectively, compared to the reference state of the grass mix without biochar (set to 100 %).