Soil Characteristics Research Articles

ON IDENTIFICATION OF PARAMETERS OF A NONLINEAR CONSOLIDATION MODEL OF SANDY SOIL

Previously, the authors of this article formulated a physically and geometrically nonlinear formulation of the problem of porous fluid-saturated medium deformation during fluid filtration (consolidation problem) in terms of the rate of solid phase displacement and the change in pore pressure in differential and variational forms. The developed consolidation model takes into account changes in the porosity and permeability of the medium during deformation. Deformation-type constitutive relations are used in the model. The developed consolidation model can be used to simulate non-stationary processes in the soil, for example, the formation of ruts and unevenness of dirt roads, as well as to calculate the uneven settlement of engineering structures. This work is devoted to the experimental determination of the deformation and strength properties of water-saturated sandy soils, which is the next stage in the consolidation process simulation. The results of the experimental determination of the bulk and shear properties of sandy soil using the ASIS automated complex (OOO NPP “Geotek”) are presented. The studies were carried out on three quartz sands of various grain sizes. To determine the volumetric moduli of dry and water-saturated sandy soils, compression tests were carried out under a continuously growing vertical load at a constant strain rate. The experiments were carried out for various strain rates in the range from 3·10–6 to 3·10–3 s–1. According to the experimental results, the bulk properties do not depend on the strain rate in the specified range. Deformation and strength shear characteristics of sandy soils were determined by the method of multiplanar shear, approximating a simple shear. The tests were carried out under a kinematically applied shear load with a given constant strain rate according to the scheme of consolidated-drained shear. The dependences of the deformation and strength properties of coarse and fine quartz sands on the shear strain rate in the range from 2·10–4 tо 4·10–3 s–1 were studied. Increasing, decreasing and nonmonotonic dependences of the internal friction angle on the shear strain rate were obtained for dry and water-saturated sands of various grain sizes. For water-saturated sands, the maximum spread in the values of the internal friction angle for different strain rates does not exceed 7 %. A technique has been developed for recalculating the obtained properties and experimental dependences into the parameters of the proposed sandy soil consolidation model.

Experimental Study on Seasonal Ground-Coupled Heat Storage and Harvesting in Cold Regions

In recent years, global efforts toward sustainable energy have intensified, aiming to reduce carbon emissions and boost energy efficiency. Heating in winter and hot water for hygiene are essential, especially in cold climates where heating demands significantly impact household energy consumption. This study examines a city in western Inner Mongolia, characterized by a severe cold climate and unique geology. A test system with dual U-shaped buried pipes for ground source heat storage and extraction was constructed, utilizing two layout schemes. Drilling tests measured formation parameters, highlighting how pipe layout and soil characteristics influence heat storage. Short-term 5-day cycles and cross-seasonal 60-day cycles were tested. Results showed upper soil suited for frequent short-term storage, while lower soil favored long-term energy retention. Increasing buried pipes raised soil temperature and storage capacity, enhancing thermal stability in short-term cycles. However, while the long-term storage capacity improved, heat loss also rose. Effective ground source heat pump design in cold regions should consider environmental temperatures, pipe optimization, soil characteristics, and heat storage duration to achieve stable, efficient operation.

Physical and Biochemical Characteristics of Soil in a Watershed of the Valley of Oueme: A Rice-based Agroforestry System in the South of Benin

The present study aimed to assess the sustainability of rice cultivation in regard to soil physical and biochemical characteristics within the watershed of the Valley of Oueme. by promoting agroforestry in rice-growing systems. For that concern, four kinds of areas were showcased for rice cultivation: Adjido. Agondo. Dame, and Houedomey. Eighty-nine thoughts of farmers on their knowledge of involvement of trees in field production were assessed. Soil samples were collected into rice fields and near of the “under trees” at 0-20 cm alongside the village of Hetin-Houedomey from April to June 2023. It was conducted into some of pieces of plots of lowland rice field to study soil physical and chemical properties. Spores’ density of Arbuscular Mycorrhizas Fungi (AMF) in that soil and their diversity were assessed. A correlation test indicated regarding quantities of clay, silt, and sand, there is a predominance of clay at the “under trees”, and in the fields, that tends to disappear little by little as we move away from trees. The pH (water) of the soil sampled is acidic and varied from 4.37 to 5.44. For chemical analysis, the average rate of total nitrogen varied from 0.218% to 1.476%. The concentrations of available phosphorus in the Valley of Oueme varied from 2 to 7 cmol/kg that revealed weak. Soils appeared to be rich in exchangeable potassium (0.21 and 1.1 cmol/kg) with the highest proportion observed under the tree in the higher topographic altitudes from the village of Dame. The Cation Exchange Capacity (CEC) for its part varied between 11.36 and 59.68 cmol/kg, and with the highest value that is in higher topographic altitudes at the Adjido county. Sixteen Glomus species of AMF were identified and the Glomus multisubstensum was the most abundant. The community of AMF was mostly diversified in the “under trees” soil, according to the Shannon index H = 5.5.

Analysis of the fluorescence spectral characteristics of dissolved organic matter in a black soil with different straw return amounts

Straw return improves soil carbon pool and dissolved organic matter (DOM) characteristics in black soil. Optimal straw return rate is the key to promoting straw return practices in farmland in Northeast China. The experiment was conducted at the Science and Technology Park of China Grain Storage and Northern Corporation in NenJiang, Heilongjiang Province, straw return at 0 kg hm−2, 3000 kg hm−2, 4500 kg hm−2, and 9000 kg hm−2. In the seventh year of the experiment, we used three-dimensional excitation-emission matrices combined with Parallel Factor analysis to characterize the fluorescence characteristics of DOM of black soils. The results showed substantial improvement in soil physical characteristics and soil organic matter (SOM) following straw return, SOM content rises in proportion to the amount of straw returned, and a significant positive correlation coefficient between water-holding capacity (WHC) (p < 0.001, r = 0.82) and dissolved organic matter (DOC) (p < 0.01, r = 0.77). Moreover, straw return significantly increased the richness of three fluorescent components, namely fulvic acid (UV and visible fulvic acids), humic-like acid, and protein-like (short and long-wavelength tryptophan). The fluorescence intensities of these components were lower in straw treatments than in no straw return. The fluorescence intensities of fulvic and humic acids showed decreasing and increasing trends, respectively, with increasing straw return amount. The fluorescence spectroscopy data of DOC demonstrated the key role of high straw return amounts in enhancing substantially the metabolic activity of soil microorganisms. Overall, straw-returning practices improve soil fertility and can be beneficial for black soil farmlands, with the optimal return rate observed at 4500 kg hm−2.

Effects of Salinity of Magnetized Water on Water–Salt Transport and Infiltration Characteristics of Soil Under Drip Irrigation

The shortage of fresh water resources and soil salinization restrict the sustainable development of oasis agriculture in Xinjiang, China. Magnetically treated brackish water can physically improve the quality of water used for irrigation, and this technology is being gradually applied in agricultural production. However, the infiltration characteristics of magnetized brackish water and its response to the distribution of soil water and salt are still unknown. We conducted infiltration tests using a one-dimensional soil column system, employing magnetized water at concentrations of 0.2, 1, 3, and 5 g·L⁻1, with a magnetization strength of 3000 gauss (GS), and explored the effects of salinity of magnetized water on water–salt transport and infiltration characteristics of soil under drip irrigation. The migration rate of the wetting front of magnetized water infiltration slowed, and the cumulative infiltration content increased. Specifically, compared to the unmagnetized control, the infiltration time at a depth of 40 cm for magnetized water concentrations of 0.2, 1, 3, and 5 g·L−1 increased by 17.42%, 42.16%, 47.02%, and 39.19%, respectively. Correspondingly, the cumulative infiltration volume increased by 7.88%, 8.09%, 10.60%, and 5.38%. Further, the infiltration of magnetized brackish water increased the water retention capacity of soil, effectively reduced the salt content of soil layers, and had a remarkable desalting effect. Salinity of the soil profile showed an L-shaped trend of salt accumulation in the lower layer and desalting in the upper layer. For water salinity of 3 g·L−1, soil desalting intensity was greatest. In addition, KShf, suction rate, empirical coefficient a, initial infiltration rate, and stable infiltration rate all decreased under magnetization treatment with the same salinity. Thus, this study provides a new way to alleviate the shortage of fresh water resources in arid areas, a guideline for safely using brackish water and also increasing productivity of saline–alkali land.

Vermicompost application improves leaf physiological activity, 2-acetyl-1-pyrroline, and grain yield of fragrant rice through efficient nitrogen assimilation under Cd stress

Cadmium (Cd) pollution in arable soils and its accumulation in rice plants have become a global concern because of their harmful effects on crop yield and human health. The in-situ stabilization method which involves the application of organic amendments such as vermicompost (VC), is frequently utilized for the remediation of Cd-contaminated soils. This study investigated the effects of VC on the soil chemical properties and the physio-biochemical functions of fragrant rice, as well as nitrogen (N) metabolism and assimilatory enzyme activities, 2-acetyl-1-pyrroline (2AP) content in rice grains, and the grain yields of fragrant rice cultivars, i.e., Xiangyaxiangzhan (XGZ) and.Meixiangzhan-2 (MXZ-2) under Cd stress condition. Four doses of VC (.VC1 = 0, VC2 = 3 t. ha-1, VC3 = 4 t ha-1, and VC4 = 6 t ha-1) and two levels of Cd (0 and 25 mg Cd kg-1) were used in this study. Our results showed that VC supplementation significantly (p &amp;lt; 0.05) improved soil characteristics, including soil organic carbon, available N, total N, phosphorus (P), and potassium (K). Furthermore, VC enhanced plant physiological and biochemical attributes in fragrant rice, such as net photosynthetic rate (Pn), nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate oxoglutarate aminotransferase (GOGAT) enzyme activities, protein contents, amino acid, and 2-acetyl-1-pyrroline (2AP) contents under Cd stress condition. Specifically, the VC-amended treatment, Cd2 + VC3, led to an 86.75% increase in Pn and 2AP, and a 60.05% and 77.55% increase in grain yield for MXZ-2 and XGZ cultivars, respectively, compared to Cd-only treated plants (Cd2 + VC1). In addition, VC application significantly (p &amp;lt; 0.05) decreased the Cd uptake and accumulation in rice plants. The correlation analysis indicated that leaf physiological activity and biochemical traits are strongly correlated with soil qualitative traits, suggesting that improved soil health leads to enhanced leaf physiological activity, N metabolism, grain 2AP content, and grain yields. Among the treatments, Cd2 + VC3 showed the best performance in terms of soil fertility and rice quality and production. Consequently, our study indicates that using VC in soils may benefit rice growers by improving soil fertility and supporting sustainable rice productivity and quality in soils contaminated with Cd.

Land-use determines the distribution of large branchiopods in climatically homogeneous northern Pannonia

Large branchiopods are key biota of temporary pools in Central European lowlands. Due to land use changes, they are among the most threatened aquatic invertebrates in Europe. The lack of information on the main drivers of species distribution hinders effective protection and conservation prioritisation. We selected eight branchiopod species with representative data on their occurrence in the northern Pannonia to identify the most important drivers of their distribution and to predict their distribution in unexplored temporary pools across the Pannonian region of southern Slovakia, south-eastern Czech Republic, and eastern Austria. Data on pool size and isolation, soil characteristics, land use and climate were used to generate species distribution models using five modelling techniques and ensemble predictions. The distribution of species was mainly affected by the proportion of arable land within the pool (e.g. Triops cancriformis, Leptestheria dahalacensis), land use (e.g. Eubranchipus grubii, Lepidurus apus) and distance from the river (e.g. Branchinecta ferox and Chirocephalus carnuntanus). Wetland size and habitat isolation were also important for some species, mainly for Branchipus schaefferi and Imnadia yeyetta, respectively. As we focused on a climatically homogeneous area, climatic conditions only had the most important effect on the distribution of species that have their distribution limit in northern Pannonia (B. ferox, C. carnuntanus, I. yeyetta). Overall, the diversity of large branchiopods increased with pool size, while decreased with distance to a river and habitat isolation. As some distribution patterns emerged repeatedly in the models, the effective protection can be simplified to consider species that require contrasting conditions. Particular attention should be paid to ephemeral wetlands on arable land, crucial habitats for large branchiopods, yet lacking any protection. Our results can contribute to better conservation of large branchiopods by facilitating surveys of species in understudied areas and improving the knowledge on the species environmental niches.

Evaluating the Impact of Phosphorus and Solid Oxygen Fertilization on Snap Bean (Phaseolus vulgaris L.): A Two-Year Field Study

The snap bean (Phaseolus vulgaris L.) is highly sensitive to both phosphorus (P) deficiency and hypoxic stress, which together can significantly hinder plant growth, nutrient uptake, and yield; however, limited information exists on the effect of P and oxygen (O2) fertilization to alleviate these stresses and enhance yield. A two-year field experiment assessed the effects of P and O2 fertilization on plant growth, pod yield, and P uptake in acidic sandy soil. Using a randomized complete block design with four replications, we tested five P rates (0, 45, 90, 135, and 179 kg ha−1 of phosphorus pentoxide, P2O5) in the form of triple superphosphate (TSP) along with two rates (0 and 45 kg ha−1) of solid O2 fertilizer as calcium peroxide (CaO2). Phosphorus and O2 fertilizers improved plant growth and pod yield, with the highest yield from the combination of 135 kg ha−1 P2O5 and 45 kg ha−1 CaO2. Pearson correlation analysis indicated strong associations between plant growth, pod yield, and nutrient accumulation. Principal component analysis (PCA) highlighted notable seasonal differences in snap bean and soil characteristics. This study provides essential insights into the use of O2 fertilizers as a cost-effective approach to mitigate hypoxia, enhance P use efficiency, and improve yield in snap bean. Our findings may inspire the development of sustainable nutrient protocols for high-quality snap bean production and serve as a foundation for similar applications in other crops.

Bacterial wilt alters the microbial community characteristics of tobacco root and rhizosphere soil

Bacterial wilt alters the microbial community characteristics of tobacco root and rhizosphere soil

Enhancing crop yield and microbial diversity in saline-affected paddy soil through biochar amendment under aquaculture wastewater irrigation

Biochar is frequently employed to ameliorate saline-affected paddy soil. However, there are controversial research findings regarding the applicability of biochar for the enhancement of soil physicochemical properties and agricultural (crop) yield, particularly under conditions of wastewater irrigation in agricultural production. This study investigates the effects of controlled soil salinity levels (1 ‰ and 3 ‰), induced using sodium chloride, and the targeted application of biochar in a pot experiment. The study examines the impact on physicochemical characteristics of different soil layers, physicochemical properties, and physiological responses of rice plants irrigated with aquaculture wastewater. It also delves into soil microbial diversity and the predominant bacterial species. The research findings reveal that biochar exerts a significant influence on soil properties and nitrogen content in saline environments. The addition of biochar enhanced soil electrical conductivity (EC), modulated the distribution of organic carbon, and altered nitrogen transformation processes within the soil. Consequently, biochar application resulted in a 14.2 % and 6.81 % increase in rice yield at 1 ‰ and 3 ‰ salinity levels, respectively. Furthermore, biochar increased leaf area by 25.3 % and 45.9 % in 1 ‰ and 3 ‰ salinity stress separately and enhanced the nitrogen content (TN) in leaves by 28.6 % when the soil salinity is 1 g/kg, demonstrating a positive impact on nitrogen uptake. Additionally, biochar has shown potential in mitigating nitrous oxide (N2O) emissions. Its addition led to a reduction in the relative abundance of Actinobacteria while increasing the relative abundance of Firmicutes. These findings provide novel insights into the transformative potential of biochar in improving the characteristics of saline paddy soil and augmenting rice yield when used in conjunction with aquaculture wastewater irrigation.

Irrigation with water from Beni Haroun reservoir (Algeria) changed soil physicochemical properties and the availability of metallic trace elements in croplands

The Beni Haroun Dam (BHD), situated in the province of Mila, Algeria, stands as the largest dam within the country, facilitating the irrigation of approximately 40,000 ha of agricultural lands characterized by sub-humid and semi-arid climates. Over time, the water within this reservoir has experienced an escalation in contamination, primarily attributed to its role as a major recipient of diverse municipal and industrial effluents, both treated and untreated. Consequently, mounting apprehensions regarding the potential migration of pollutants to irrigated soils have surfaced. The primary aim of this investigation was to assess the levels of contamination by mineral elements and heavy metals present in agricultural soils irrigated by waters originating from BHD. A total of 48 soil samples were systematically collected from 12 distinct sites, comprising 10 irrigated areas and 2 control sites, each spanning depths of 0, 10, 20, and 30 cm. Then subjected to chemical characterization, including the total quantification of minerals (Ca2+, Mg2+, Na+, K+), and heavy metals (Cd2+, Cu2+, Zn2+, Pb2+, Cr3+ and Fe3+). as well as the determination of cation exchange capacity (CEC), exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR) as well as soil texture. This study indicated that irrigating with dam waters increased the soil exchangeable cations in comparison to the control one: Ca2+ (21.99 ± 3.65 meq 100 g−1), Mg2+ (10.53 ± 1.94 meq 100 g−1), Na+ (10.08 ± 1.78 meq 100 g−1), K+ (2.81 ± 0.8 meq 100 g−1), and enhanced soil characteristics: CEC (25.2 ± 5.55), ESP (41.69 ± 11.21) and SAR (2.51 ± 0.43). In terms of percentage of enrichment, the mineral elements are classified as follows: Na+ > Ca2+ > K+ > Mg2+. The metal contents in irrigated soils were also higher but remained less than the recommended international limits. They are classified as follows: Fe3+ > Zn2+ > Pb2+ > Cr3+ > Cu2+ > Cd2+. Consequently, the soils under investigation are deemed susceptible to salinization, sodification, and contamination with prolonged irrigation. Such conditions pose potential risks to human health should vegetable crops absorb these metals. Therefore, it is recommended to implement adequate drainage measures, emphasizing surface drainage, and to conduct regular monitoring for the accumulation of salt and sodium.

Degradation of 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) in soil by FeS activated persulfate: Kinetics, mechanism, and theoretical calculations

2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) is a commonly used benzotriazole ultraviolet stabilizers (BUVs) with bioaccumulative properties. Since it’s stubbornly degraded in the environment, it poses significant environmental risks in soil. However, the removal of UV328 from soil is challenging, and existing treatment methods have low efficiency. This study focuses on UV328 in soil and proposes an efficient method for its removal using persulfate (PS) activated by iron sulfide (FeS). The research demonstrates that with FeS and PS dosages of 20 and 100 mM respectively, and a soil-to-water ratio of 5:1, 12 h-removal efficiency of UV328 with an initial concentration of 12 mg/kg reaches 93.0%. Furthermore, employing electron paramagnetic resonance spectroscopy and quenching experiments, key reactive oxygen species (ROSs) are identified. SO4•-, •OH, 1O2 and •O2- contribute 31.76%, 28.77%, 26.52% and 12.95%, respectively. Four main reaction pathways of amination, hydroxylation, sulfate substitution, and bond cleavage, are identified with 14 transformation products characterized. Calculated energy profiles based on density functional theory (DFT) identify the most susceptible reaction sites for different ROSs. Five different types of agricultural soils were selected to explore the impact of soil characteristics on UV328 removal. The degradation performance of natural mackinawite demonstrates the effectiveness and accessibility of raw materials. Toxicity assessments of transformation products confirm the environmental friendliness of this system. This study proposes an efficient degradation method for UV328-contaminated soil, providing scientific insights and theoretical guidance for addressing environmental removal of BUVs from soil.

Advanced characterisation of groundwater contamination at a dumpsite: Methodology and assessment - Case study of a municipal solid waste dumpsite in India.

Groundwater (GW) contamination due to municipal solid waste (MSW) disposal in open dumpsites is a pressing global issue. Traditional GW assessment studies are limited to single-depth sampling from nearby wells/handpumps, providing limited insights into subsurface soil characteristics and are prone to cross-contamination. The present study introduces an innovative methodology integrating advanced techniques: Cone Penetration Testing (CPT), Hydraulic Profiling Tool (HPT), Continuous Soil Sampling, and Discrete GW Sampling. Conducted at an operational dumpsite in New Delhi, India, from January to February 2023, the site investigation program covered seven distinct locations to incorporate the entire dumpsite area. The investigation proceeded in stages, starting with subsurface soil characterisation using CPT and HPT, followed by extracting soil and GW samples using CPT and HPT data. Due to restrictions in the northeast direction, GW samples were directly extracted from borewells. The results revealed maximum and minimum concentrations of 171 items/l and 26 items/l of MPs, while ionic concentration reached 13,200ppm for Cl- and 4437ppm for SO4-2. A maximum of 0.721ppm, 0.663ppm and 0.948ppm concentration was observed for Ni, Cu and Mo in GW samples. Spearman correlation and principal component analysis underscore the influence of Ec, TDS, Na+1 and Cl-1 on GW quality. This integrated approach effectively identifies high-permeability layers, which are crucial for understanding contaminant dispersion, and ensures precise sampling at various depths with minimal cross-contamination. This research demonstrates the proposed methodology's effectiveness in providing more profound and precise insights into GW contamination dynamics and suggests its utility in forming the basis for more effective remediation and regulatory strategies.

Soil properties and microbial evolution during cropping system conversion: Insights from a 105-year study in southern China

Understanding the mechanisms by which soil environments and microbial communities evolve in response to long-term changes in cropping systems is essential for the development of effective ecological conservation and restoration strategies. In this study, variations of soil characteristics and the succession of microbial community assemblages and functions were investigated in southern Chinese deciduous forests and adjacent converted tea plantations at different ages (20, 40, 60, and 105 years). The results revealed significant alterations in soil properties and the emergence of distinct diversity patterns and assembly mechanisms for bacterial and fungal communities over the century-long succession period. Bacterial α-diversity exhibited a declining trend throughout succession, while fungal α-diversity experienced a rebound in the later stages. Null model analysis indicated that stochastic processes primarily drove the assembly of the bacterial community in both forests and tea plantations, whereas fungal community assembly gradually shifted from stochastic dominance to deterministic dominance. The strength of interactions between bacterial taxa in tea plantations decreased over time, but the topological properties of fungal networks were restored in tea plantations aged 60 and 105 years. The functional groups of bacteria associated with carbon cycling and saprotrophic fungi significantly increased after tea cultivation, which was closely linked to the proliferation of r-strategists stimulated by sufficient nutrients in tea plantations. It is noteworthy that in addition to typical environmental variables such as nutrients and pH, soil polyphenols in tea plantations also have a profound effect on the composition and assembly processes of bacterial and fungal communities. These findings advance the current understanding of how long-term cropping system changes affect soil microbial community assembly and functionality, and highlight the distinct strategies by which bacteria and fungi respond to cropping system change.

Biodiversity and Soil Characterization of Ancestral Domain of the Tagbanua Tribe in Aborlan, Palawan, Philippines

This study was conducted to determine strategies to enhance the sustainable forest management practices of the Tagbanua tribe. Specifically to describe the biodiversity and soil characteristics of the ancestral domain. The modified belt-transect method for biodiversity assessment developed by B+WISER (2014), further modified by the Department of Environment and Natural Resources (DENR) in the assessment, was used in this study. Results of soil chemical analysis showed significant variations among various land uses. The ancestral domain had at least 73 plant species belonging to 34 families and 59 genera. Four (4) taxa whose SN/families were still undetermined and another three (3) genera under families Annonaceae, Meliaceae, and Sapindaceae were unidentified. It had 12 plant species that are threatened with one critically endangered based on the list of threatened Philippine plants of the DENR. On the other hand, a total of 372 birds representing 61 species from 29 families were recorded. The high Shannon-Weiner Diversity Index (H’=3.69) and Shannon’s Evenness (HE=0.90) values indicate high avifaunal diversity and equitable distribution among the detected species. Most of the conservation priority species recorded in the area are Palawan endemic species. The survival of these birds is threatened by extinction due to habitat loss. This observation emphasized the importance of the ancestral domain as a refuge for these endemic species and conservation priority areas.

Innovative Organic Fertilizers and Cover Crops: Perspectives for Sustainable Agriculture in the Era of Climate Change and Organic Agriculture

Anthropogenic activities have resulted in land desertification in various regions of the world, leading to the degradation of critical soil characteristics such as organic matter (OM) content, nutrient stock, and prevailing biodiversity. Restoring such degraded soils through organic matter amendments and diversified crop rotations is thus an intrinsic part of organic farming. This review discusses a wide range of organic farming impacts on soil health and crop productivity by focusing on organic fertilizers and crop diversification. Conventional fertilizers were considered vital for agricultural production to harvest high crop yields. Nevertheless, they are now deemed as environmentally hazardous and an obstacle to sustainable agroecosystems due to intensive chemical inputs that damage the soil over time and have long-lasting impacts. Conventional fertilization results in nutrient depletion, loss of microbial diversity, organic matter reduction, and deterioration of physical characteristics of the soil. Conversely, organic fertilization makes use of naturally existing resources to improve soil health. Organic amendments such as biochar, manure, and fermented grass improve soil’s physical, chemical, and biological properties and promote the growth and diversity of beneficial soil microorganisms—important in nutrient cycling and soil stability. They facilitate the uptake of nutrients, hinder crop pathogen growth, mitigate heavy metals, and decompose xenobiotic organic substances. Moreover, growing cover crops is also a major strategy to improve soil health. Diversified crop rotation with combinatorial use of organic fertilizers may improve soil health and agricultural yields without any detrimental impacts on the environment and soil, ensuring sustainable food production, safety, and security. This integrated approach contributes to minimizing the use of chemical fertilizers and their effects on environmental health. It also contributes to reducing agricultural inputs along with enhancing OM, soil microbial diversity and biomass, nitrogen fixation, and carbon sequestration. Therefore, cover crops and organic fertilization may offer sustainable agroecosystems and climate change mitigation.

Varying extractability of petrogenic and pyrogenic polycyclic aromatic hydrocarbons (PAH) in urban soils: Evaluation of sample preparation and extraction of 71 PAH and alkylated PAH

PAH extraction methods have been widely studied over the last decades. However, there is still no consistent method for contaminated soils. Here, for the first time, PAH source characteristics in soils were considered for the investigation of different pretreatment methods, extraction techniques and solvents in nine petrogenic to primarily pyrogenic urban soils. Sources were identified by macroscopic identification of source substrates and analysis of 71 PAH and alkylation patterns.The comparison of extraction solvents revealed that a combined sequential extraction using dichloromethane (for petrogenic PAH) and toluene:methanol (6:1) led to the highest extraction efficiencies for all samples and is therefore best suited for PAH analysis of unknown samples. Acetone:n-hexane led to the lowest extraction efficiencies for all samples and is not recommended as extraction solvent. The comparison of extraction techniques showed that Pressurized Solvent Extraction is more efficient than ultrasonic extraction especially for petrogenic PAH, but also for pyrogenic PAH. Grinding increased PAH extractability considerably but mainly for petrogenic PAH from bituminous coal particles. In mixed to primarily pyrogenic samples with a smaller proportion of coal, the enhanced extractability of coal leads to a more petrogenic PAH distribution and consequently a decrease in the source identifying PAH Alkylation Index.It is concluded that PAH contents in unknown (urban) soils, where pyrogenic and petrogenic PAH can be present, cannot generally be compared if different extraction techniques, different extraction solvents and grinding or no grinding are applied. As extraction efficiency increases with more effective methods and solvents for bituminous coals, it is recommended to define a specific extraction technique and solvent mixture for improved comparability in future PAH analyses.

Integration of VIS–NIR Spectroscopy and Multivariate Technique for Soils Discrimination Under Different Land Management

Proximal sensing has become increasingly popular due to developments in soil observation technologies and the demands of timely information gathering through contemporary methods. By utilizing the morphological, physical, and chemical characteristics of representative pedogenetic profiles established in various soils of the Sohag governorate, Egypt, the current research addresses the characterization of surface reflectance spectra and links them with the corresponding soil classification. Three primary areas were identified: recently cultivated, old cultivated, and bare soils. For morphological analysis, a total of 25 soil profiles were chosen and made visible. In the dark room, an ASD Fieldspec portable spectroradiometer (350–2500 nm) was used to measure the spectrum. Based on how similar their surface spectra were, related soils were categorized. Ward’s method served as the basis for the grouping. Despite the fact that the VIS–NIR spectra of the surface soils from various land uses have a similar reflectance shape, it is still possible to compare the soil reflectance curves and the effects of the surface soils. As a result, three groups of soil curves representing various land uses were observed. Cluster analysis was performed on the reflectance data in four ranges (350–750, 751–1150, 1151–1850, and 1851–2500 nm). The groups derived from the soil surface ranges of 350–750 nm and 751–1150 nm were not the same as those derived from the ranges of 1151–1850 nm and 1851–2500 nm. The last two categories are strikingly comparable to various land uses with marginally similar features. Based on the ranges of 1151–1850 nm and 1851–2500 nm in surface spectral data, the dendrogram effectively separated and combined the profiles into two separate clusters. These clusters matched different land uses exactly. The results can be used to promote the widespread usage of in situ hyperspectral data sets for the investigation of various soil characteristics.

Physico-Chemical Soil Analysis of Agriculture Farm in Sangam University, Bhilwara, Rajasthan

Abstract: The current study, conducted in 2022, examined the physico-chemical characteristics of soil at Sangam University (SU) in Bhilwara, Rajasthan. Soil sample was collected 15 cm depth from Sangam crop cafeteria and Sangam farm and them analyzed for assessing the soil physical properties and availability of macro-nutrient present in soil of selected locations. Soil textural classes were clay loam and sandy loam. Bulk density 1.06gcm-3 (SU farm) and 1.11 gcm-3 (SU Campus) in both field water holding capacity 59% and 54% was good. Electrical conductivity 0.25- 0.66 dSm-1 (SU farm) &amp; 0.26- 0.80dSm -1 (SU Campus) are safe range and organic carbon 0.43% &amp; 0.42% is in sufficient amount of both area. Soil pH 7.5 &amp; 8.0 is neutral to slightly alkaline. The available Phosphorus 54 kg ha-1 and 42 kg ha-1 , Potassium 140 kg ha-1 and 130 kg ha-1 in Sangam farm and campus. Hence, it is suggested to add required amount of gypsum, FYM and compost in the soil.

Laboratory-based assessment of geotechnical characteristics of organic waste-amended soil for landfill biocover.

A landfill biocover is essential for addressing environmental concerns, especially in waste management, as it plays a crucial role in mitigating the release of methane gas. This study investigates the geotechnical characteristics of soil amended with organic wastes for landfill biocover applications. Various organic waste amendments, viz., rice husk, crushed coconut coir, and compost, were examined at different percentages (0%, 25%, 50%, and 75%) compared with conventional landfill cover material, i.e. natural clay, as biocovers. Laboratory experiments analysed geotechnical characteristics, including organic content, Atterberg limit, compaction, consolidation, and desiccation cracking. The study revealed that organic waste amendment significantly impacted the geotechnical characteristics of landfill biocover, enhancing organic content and porosity and reducing permeability and desiccation susceptibility. Soils amended with organic content support methanotrophic bacteria growth and reduce methane emissions in landfills. The most promising biocovers were identified as 75CR (crushed coconut coir/wastewater sludge/clay in percentage ratio of 70:5:25), followed by 75CT (compost/wastewater sludge/clay in percentage ratio of 70:5:25), and 25RH (rice husk/wastewater sludge/clay in percentage ratio of 20:5:75). Biocovers offer sustainable landfill alternatives, underscoring the need to understand their geotechnical characteristics for successful installation in landfills.