Low Organic Content Research Articles

The Genesis and Significance of Pyrite in the Ordovician Majiagou Formation in the Central and Eastern Ordos Basin

The geochemical data of the gas sourced from the Majiagou Formation indicate low organic content and high thermal maturity, which make the evaluation of the hydrocarbon generative potential difficult. However, the low organic abundance and high thermal maturity of the Majiagou Formation make it difficult to evaluate its hydrocarbon generation potential. The Study of the genesis of pyrite can provide a better understanding of a source rock depositional environment and its evolution. In this paper, we report a significant amount of pyrite linked to the hydrocarbon source in the Majiagou Formation. Light and electron microscopy were used to observe the morphology pyrite while sulfur, carbon, and oxygen isotope were used to investigate the geochemical characteristics of pyrite and the surrounding rock matrix. The results showed that macroscopic stellate pyrite filled cracks and is found in veins or along the laminar surface, as well as agglomerated pyrite; microscopically, pyrite is dominated by autotypic pyrite in the form of cubes, pentagonal dodecahedrons, and columns. The δ 34 S CDT ranged from 4.6‰ to 27.5‰, δ 13 C PDB values ranged from −3.4‰ to −2.3‰, and δ 18 O PDB values ranged from −10.5‰ to −7.3‰. Our findings, combined with the geological background and thermal history of the region, the pyrite in the Majiagou Formation was formed by thermochemical sulfate reduction. Indicating that large-scale hydrocarbon generation events have occurred. The rocks of the Majiagou Formation had the ability to generate hydrocarbons. The research can be utilized as supporting material for the exploration and development of natural gas fields in the Ordos Basin.

Enhancing resource recovery from acid whey through chitosan-based pretreatment and machine learning optimization

Acid whey, a dairy byproduct with low pH and high organic content, presents disposal challenges but also potential for resource recovery. In this study, chitosan gel was synthesized and evaluated for turbidity reduction of acid whey. Machine learning (ML) models were employed to predict and optimize the pretreatment process, with the Random Forest algorithm achieving a prediction accuracy of 0.78. Using the Simulated Annealing algorithm, optimal conditions were identified, applying a 2.2 % chitosan solution gel at a dosage of 24 g/L to acid whey at pH 4.6 for 12 h, achieving a 91 % turbidity reduction, a significant improvement over the 71 % obtained prior to optimization. Validation experiments confirmed its effectiveness in predicting and optimizing the pretreatment process. These findings highlight the feasibility of ML in optimizing chitosan pretreatment and demonstrate chitosan gel as a cost-effective, efficient option for acid whey, with potential to enhance resource recovery in the dairy industry.

Benthic Mollusk Biodiversity Correlates with Polluted Sediment Conditions in a Shallow Subtropical Estuary

To quantify the ecological impacts of organic sediments and environmental dredging, benthic mollusks were chosen as bioindicators of environmental change, measured as sediment organic content and associated parameters. Data on species richness, ecological diversity (which was measured as biodiversity), and abundances were collected alongside sediment and near-bottom water quality data before, during, and after environmental dredging. Organic sediment content was found to have an inverse logarithmic relationship with benthic mollusk biodiversity, species richness, and abundance. Post hoc analyses found that percent dissolved oxygen, which correlates with sediment organic content, was responsible for 29.31–34.12% of the benthic mollusk community variation. Sediments with lower organic content had higher biodiversity (organism densities up to 1 organism m−2), abundance (over 2.0 × 105 organisms m−2), and species richness (organism densities up to 4 organisms m−2). In comparison, sediments with higher organic content had low biodiversity (organism densities 0–1 organisms m−2), abundance (as low as 0 organisms m−2), and species richness (organism densities as low as 0 organisms m−2).

Influence of degree of cultivation of sod-podzolic soil on dynamics of content of soil organic carbon

In 1999–2001 on the fields of the Falenky Breeding Station (Kirov region), the dynamics of the content of soil organic carbon (Corg) and its labile part (Clab) in sod-podzolic arable soil of varying degrees of cultivation were studied. The arable layer of weakly cultivated variant of the soil was characterized by high acidity (pHKCl – 3.88) and low organic carbon content (Corg – 0.91 %). The well cultivated variant had an acidity close to neutral in the arable horizon (pHKCl – 6.14) and a total carbon content at the average level for sod-podzolic loamy soils of the region (Corg – 1.10 %). Soil samples were taken during the growing season once a month in a sixfold repetition from the arable horizon and in a threefold repetition for horizons A2B and B. It was revealed that during all years of observation in the arable horizon of the soil of the cultivated variant, the Corg content was significantly higher (by 16–76 %). In the underlying horizons of soils of both variants, the carbon content was sharply reduced to 0.2–0.6 %. The content of labile part of organic carbon did not differ by variants and varied from 0.05 to 0.19 % depending on the horizon and observation period. However, in the arable horizon of weakly cultivated soil, the proportion of labile carbon in the composition of total organic carbon was significantly higher, which indicated less stability of the soil organic matter system. The content of both forms of soil organic matter varied significantly over the years and during the growing season. Maximum values of Corg content were noted at the beginning and at the end of the observation season. Minimum values were noted in July. Content of Clab was decreasing from the beginning to the end of the season.

Use of lignocellulose-degrading enzyme bio-cemented soils in the construction industry

In their activity, termites break down biomass into glucose, forming cementitious compounds. This results in rainfall-resistant mounds for their shelters, which interests the construction industry. This study explored the potential application of the abundant naturally bio-cemented termite mound soils in highway construction. Experimental investigations compared these mound soils to surrounding soils, revealing that mound soils are 68.2% finer in particle size distribution and have 81.4% lower organic content. Atterberg limits indicated 14.6% higher plasticity and a 5.3% increase in specific gravity for mound soils. Atomic absorption spectroscopy showed no significant difference in chemical composition. Proctor tests indicated that the compaction characteristics of the soils were comparable, confirming their engineering viability without modifications. Mound soils exhibited a twofold increase in unconfined compressive strength and a 33.9% increment in California Bearing Ratio strength. One-way analysis of variance tests confirmed these differences with p-value ranges of 0.0056–0.0361 below the 0.05 significance threshold. The study advocates utilising eco-friendly naturally bio-cemented mound soils in highway construction, meeting minimum standards. Mound soils from one acre can construct up to 2,500 m highway, optimising resource use, promoting sustainability by repurposing natural materials, and significantly reducing carbon dioxide emissions. Further research on soil improvement using lignocellulose-degrading enzymes is recommended.

Using Biodegradability of Sewage in Ordinary Pit Latrines to Assess their Agricultural Potentials

This research investigated the use of biodegradability of sewage in ordinary pit latrines to assess the performance of such sewage for agricultural purposes. The objective of this paper therefore was to study the biodegradability of faeces in selected pit latrines that would lead to the assessment of the performance of such pits. Both aerobic and anaerobic biodegradability of pit sludges were thus measured. Samples of fresh faecal sludges collected from pit latrines in selected households in Aku community were subjected to laboratory analyses for their physico-chemical and biological characteristics. The results showed that in terms of biochemical oxygen demand (BOD), twelve (12) pits had biodegradability of 80 Parsant and above. In the case of chemical oxygen demand (COD) and suspended solids (SS), nine (9) pits had biodegradability of 80 Parsant and above. For the volatile solids (VS), eleven (11) pits had biodegradability of 80 Parsant and above. Ten (10) pits had ratio of volatile solids to total solids (VS: TS) ranging from 0.90 – 2.93. Using COD: BOD ratio, eleven (11) pits had values ranging from 0.90–1.34 indicating that the pits sludges were readily biodegradable and good for agricultural purposes. Lower values showed lower organic contents and lower biodegradability and therefore unsuitable for agricultural purposes. High COD: BOD, VS:TS ratios should therefore be used to assess the performance of pit latrine sludges for higher agricultural productivity considering good user-behaviour, favourable soil and environmental conditions. Excreta collected from such pits should be used to enhance soil fertility.

Factors governing crusting formation in soils in Southern Mali, West Africa: Evaluation of susceptibility indices

In Southern Mali and neighboring semi-arid Sahel regions, soil crusting and sealing are common and significant phenomena for people who depend on agriculture for their livelihoods. These processes form hard, impermeable layers on the soil surface, reducing water infiltration, increasing runoff and erosion, and hindering germination, seedling emergence, and productivity. Factors such as rainfall intensity, topography, soil attributes, and poor management practices contribute to these phenomena. Here, we aimed to analyze soil attributes affecting crust formation and evaluate them using indicators like the structural stability index (StI), particle separability index (PSI), and crusting susceptibility index (CSI). Soils samples from agricultural and native areas in Southern Mali were analyzed for physical, chemical, mineralogical, and micromorphological attributes. Results revealed that the soils in these regions have high silt and fine sand content and low organic carbon content. Poor soil management, leading to prolonged periods of bare soils, significantly contributes to crusting. Kaolinitic clays, Ca2+ and Mg2+ contents did not appear to affect crusting. The PSI revealed a high risk of aggregate disruption in both agricultural and native lands, demonstrating soil vulnerability to degradation. The StI showed limited risk of structural degradation in native lands, while agricultural soils were more susceptible to crusting. The CSI indicated moderate crusting susceptibility across the regions. By examining the three indices related to texture attributes and organic carbon, this study provides insights into estimating susceptibility to crusting through the evaluation of the risk of soil structural degradation, particle separation, and overall soil susceptibility to surface crusting, all of which underscore the need for improved soil attributes. It emphasizes the importance of implementing effective soil management strategies, particularly the adoption of cover crops, to enhance organic carbon content and increase vegetation cover. These measures are essential for improving soil health and minimizing the risk of crusting.

Analysis of chemical and morphological properties of root dentine treated with a single multifunctional endodontic irrigant solution.

The aim was to evaluate the chemical, morphological aspects and microhardness of root dentin after treatment with Triton™ solution. Twenty blocks of root dentin were distributed in two groups (n = 10): Control (C) (2.5% NaOCl+17% EDTA+2.5% NaOCl) and Triton™ solution (T). Morphological analysis was performed before and after treatments with confocal laser microscopy. Chemical composition and microhardness were analysed after the treatments using Raman spectroscopy and Knoop microhardness. Results were submitted to Student's t-test and Mann-Whitney test (p < 0.05). The C group had greater tubule number, area and perimeter (p < 0.001), besides a regular surface, while T showed an irregular surface with cracks and erosions, lower organic content intensity (p < 0.001) and higher inorganic/organic ratio (p = 0.003) than C, which had higher microhardness than T (p = 0.003). Triton™ exposed a lower number, area and perimeter of dentinal tubules, with cracks and erosions in root dentin. It also showed significant chemical alterations in the organic content, reducing it, resulting in lower microhardness.

Carbon preference by Cupriavidus necator for growth and accumulation phases: Heterotrophic vs. autotrophic metabolisms

Cupriavidus necator is a mixotrophic microbe capable of metabolizing both organic carbon (heterotrophic) and CO2 (autotrophic) for cell growth and biodegradable plastic synthesis. This study investigates C. necator's behavior under mixotrophic conditions for cell growth and polyhydroxyalkanoate (PHA) accumulation. Various concentrations of organic substrates (acetate and butyrate from 10 to 1000 mg/L) and gaseous substrates (H2, O2, CO2) were examined to monitor C. necator's substrate preferences. The results indicated a clear preference for organic carbon over CO2 during cell growth. At relatively low organic concentrations (10–100 mg/L), gas utilization began after complete consumption of organic substrates. On the other hand, higher concentrations (500–1000 mg/L) led to a shift from the heterotrophic to mixotrophic metabolism around the 10-h mark due to the abundance of substrates. During PHA accumulation, C. necator initially favored the gaseous substrates (H2 and CO2) before shifting to the organic substrates, with mixotrophic behavior observed immediately at low organic concentrations. Additionally, high CO2 partial pressure (>0.4 atm) inhibited microbial growth in both autotrophic and heterotrophic metabolisms. These findings highlight C. necator's adaptability under mixotrophic conditions and demonstrate the potential for mass-scale applications, such as microbial electrolysis cells to optimize biopolymer production and substrate utilization.

Assessment of two benzylation strategies for the analysis of nerve-agent derived ethyl- and pinacolyl methyl phosphonic acids in sandy loam soil by GC–MS

Despite their prohibition by the Chemical Weapons Convention, nerve agents (NAs) remain in use against military and civilian targets. Due to their high reactivity, NAs readily degrade to phosphonic acids, making them important markers in the inspection of areas of presumed NA use. In this work, we assess the use of benzylation to modify ethyl- and pinacolyl methylphosphonic acids, degradation products of VX and Soman respectively, for their efficient detection in a soil matrix at ∼10 and ∼1 μg/g using GC–MS. The soil matrix, Sandy Loam (SL), was chosen for its ubiquitous nature, complex composition with silica particles embedded in clay, and low organic content. In this study, we demonstrate that benzylation via benzyl bromide yields a LOD = 25.6 ng/mL for benzylated-EMPA and LOD = 30.1 ng/mL for benzylated-PMPA. This is superior to the use of p-methoxybenzyl trichloroacetimidate in providing stable phosphonic acid ester derivatives for analysis. A base-modified procedure for p-methoxybenzylation was explored in this study yielding a LOD = 29.1 ng/mL for p-methoxybenzylated-EMPA and LOD = 39.8 ng/mL for p-methoxybenzylated-PMPA. Both benzylation pathways (benzyl bromide and p-methoxybenzyl trichloroacetimidate) can be used to yield phosphonic acid derivatives that provide further confirmation of these Soman and VX degradation products in soil samples in investigative scenarios. The work herein represents the first application of benzylation methods for the analysis of these NA markers in the acidic, silicon-based SL soil.

Biofilm growth Dynamics in a Micro-Irrigation with Reclaimed Wastewater in the Field scale.

The dripper clogging due to the development of biofilm can reduce the benefits of micro-irrigation technology implementation using reclaimed wastewater. The narrow cross-section and labyrinth geometry of the dripper channel enhance the fouling mechanisms. The aim of this study was to evaluate the water distribution and biofouling of drip irrigation systems at the field scale during irrigation with treated wastewater. Six 100 m lines of commercial pipes with two pressure-compensating dripper types (flow rate, Q, of 0.65 L.h-1 and 1.5 L.h-1, respectively) were monitored for four months. Different zones along the pipes were selected to evaluate the influence of hydrodynamical conditions (Reynolds number = 5400 to 0) on biofouling. Destructive methods involving the biofilm extraction by mechanical means, showed little biofilm development without significant differences in dry and organic matter content in function of the sampling location along the pipe or dripper flow rate (Q0.65 and Q1.5). These results were confirmed by non-destructive methods, such as optical coherence tomography, that nevertheless showed that biofouling concerned 15-20% of the total dripper labyrinth volume. Total organic carbon monitoring and its composition (by three-dimensional excitation and emission matrix fluorescence microscopy) showed that the biofilm did not significantly influence the organic matter nature. Our results indicated that the biological activity and biofilm development in irrigation systems were more affected by the environmental conditions, particularly water temperature, rather than flow conditions. This confirmed that treated wastewater with low organic content can be used in micro-irrigation systems without significant loss of efficiency, even in conditions requiring intensive irrigation, such as the Mediterranean climate.

Utilizing diatomaceous earth (DE) as a sustainable substitute in alkali-activated cementitious materials: Performance and life cycle assessment

As the demand for alkali-activated cementitious materials (AACM) increases, reliance on blast furnace slag (BFS) raises concerns about potential shortages. This study evaluates the substitution of BFS with diatomaceous earth (DE) in AACM, using three DE types—raw (RDE), calcined (CDE), and spent (SDE)—at substitution rates of 0–30 %. The impact of these substitutions on fluidity, setting time, and compressive/flexural strength of the prepared mortar was assessed, along with an analysis of the mechanisms through hydration heat, product composition, and pore structure. Results indicate that DE, characterized by the porous structure and high content of amorphous silica, enhances early hydration, reduces fluidity, accelerates setting times, and refines pore structure, thereby improving strength. CDE, with its low organic content and large surface area, exhibited the best performance, while SDE was effective despite impurities, and RDE performed the poorest. Increasing DE substitution raised water absorption, impacting fluidity and setting times, with 20 % identified as the optimal substitution rate, balancing strength and workability. The entropy method-analytic hierarchy process (EM-AHP) confirmed this rate, with CDE as the optimal variant. Life cycle assessment (LCA) showed that while SDE reduces environmental impacts significantly, CDE achieves a greater reduction when considering both environmental and mechanical performance. In conclusion, CDE and SDE are viable BFS substitutes in AACM, offering enhanced performance and reduced environmental impacts.

Shift of bacterial and fungal communities upon soil amelioration is driven by carbon degradability of organic amendments

The structural response of bacterial and fungal soil communities to four carbon-rich organic amendments of increasing recalcitrance was investigated. Wheat straw, green compost, a mixed product based on biogas residues, and a fermented biochar were applied to a sandy agricultural soil of low organic carbon content. After laboratory incubation for 6 months, the community structure was investigated via DNA sequencing. All amendments caused changes in the communities of bacteria and fungi, but to different extents, with the communities exposed to more recalcitrant amendments showing the least variation compared to the non-amended soil. Changes in species composition as well as their relative abundances were observed. While the straw had a pronounced effect on bacteria (e.g., the highest number of indicator species), effects of the composted, fermented, or pyrolyzed materials were minor. Hierarchical clustering showed that the fungal communities were more different from each other than the bacterial ones with the straw-soil being most different and the biochar-soil least different from the non-amended soil. While the abundant fungal species in biochar-soil and non-amended soil were very alike, especially rare fungal species shifted upon addition of biochar. An indicator species analysis identified specific taxonomic groups which were triggered by the different organic materials. We conclude that bacterial and fungal communities strongly change upon input of degradable carbon (straw), while fungi in particular respond to the application of processed organic materials. With this study, we report the consequences of applying organic materials for the microbial community in one soil. We provide these data for meta-analyses that are required to unravel all relevant interactions across different soils, organic materials, and time. This will allow to better understand and predict the effects of organic soil amelioration measures on soil microorganisms.

A life cycle-based comparison study of sludge recycling technology incorporating subjective and objective evaluations

Inadequate land capacity and low sludge recycling rates have become a major global environmental challenge. Low organic sludge content and inadequate waste management policy mean that there is an urgent need to improve sludge solutions in China, which has the world's largest WWT capacity. Decision-makers face difficulties in selecting sustainable sludge-to-resource technologies given the existence of multiple social, environmental and economic objectives, and also in optimizing the allocation of sludge between different available technologies. In this paper we used a combined analytic hierarchic process (AHP) and entropy weight (EW) method to evaluate four recycling technologies: aerobic composting (AC), dry-incineration (DI), hydrothermal carbonization (HTC) and pyrolysis (PY), in terms of five economic, environmental and land resource indicators. The results showed that human toxicity was viewed as the most important indicator, while economic value of sludge product was the least important. HTC had the best overall performance of the evaluated technologies while PY was the least attractive. However, all four sludge recycling technologies showed greater potential for reducing carbon emissions and human toxicity than landfilling when sludge dewatering was included. Sensitivity analysis showed that adjustments to AHP weights only had a limited impact on the technical ranking. Finally, the result was further verified by a particle swarm optimization algorithm. Considering capacity constraints, the optimal proportion of the four technologies was found to be 44.9%, 42.7%, 0 and 12.4% for HTC, DI, PY and AC respectively. The paper demonstrates the effectiveness of combining subjective and objective methods to evaluate multiple indicators, providing decision-makers with a practical analysis framework for waste technology selection.

Devastation of the cerrado of mato grosso do sul and the advance of arenization in the pardo river watershed

Despite the significant biodiversity in the Cerrado, the process of occupation, subsequent economic cycles, and intensification of agriculture in a predatory manner have caused profound alterations in this biome. This study analyzed changes in land use and land cover in the Cerrado of Mato Grosso do Sul between 1985 and 2022 by mapping and also investigating the formation and dynamics of sand dunes in the Bauru sedimentary basin, focusing on the Pardo River watershed. MapBiomas Network data, collection 8, were used for land use and land cover analysis. Arenization foci cartography was conducted using brightness index 2 based on Sentinel-2 satellite images in Sentinel Application Platform software. The historical analysis of land use and cover in the Cerrado of Mato Grosso do Sul revealed a rapid transformation of the landscape, with a drastic reduction of native vegetation and an intensification of large-scale monocultures. Between 1985 and 2022, the Cerrado of Mato Grosso Sul lost 4.6 million hectares of native vegetation (forest formations, savannahs, grasslands, and wetlands), representing 24.54% of this territory. Recent changes in land use include pasture-soybean and pasture-eucalyptus. In the Pardo River watershed, arenization foci cover an area of 17,834.34 hectares, with varying dimensions ranging from less than 1 hectare to 376.41 hectares. The arenization process occurs in different slope compartments, such as the base, slope, and interfluves. The physical and chemical characteristics of Quartzipsamments, such as low organic carbon content in soil, are associated with high rates of surface exposure and weakened load-dependent structures, leading to degradation. Arenization occurs where natural vegetation has been suppressed and soil has been depleted by poorly managed production processes.

Effects of farmyard manure and chemical fertilizer application rates on soil biology, cotton and fiber yield

Organic and inorganic fertilizers have significant effect on plant physiology, yield per unit area, available plant nutrient contents and extracellular enzyme activities of soils. This study was carried out in field conditions in arid and semi-arid regions between 2020-2021 years, May 01. The effects of farmyard manure (FM) (20, 40, 60 Mg ha-1) and chemical (CF) (350 kg urea ha-1, 100, 200, 300 kg DAP ha-1) fertilizers applied at different rates on plant nutrient (N, P, K, Ca, Mg, Fe, Cu, Zn and Mn) contents, SPAD value and NDVI of cotton plants, seed cotton yield and soil enzymes (urease, catalase, dehydrogenase, alkaline phosphatase) were investigated. The results showed that FM applications significantly (p&lt;0.01) increased the plant macro and micronutrients compared to CF applications, except for N (200 + 150 kg urea ha-1), Zn and Cu (300 kg DAP + 200 + 150 kg urea ha-1) in the 2021 cotton growing season. Mineralization of FM is slow under natural conditions; therefore, the use of FM alone is not sufficient to meet the nutrient needs of high yielding varieties. Urease and dehydrogenase activities increased significantly in FM treated soils compared to CF, while no significant (p&lt;0.01) increase was recorded in alkaline phosphatase and catalase activities. Farmyard manure is a useful management practice for increasing soil biological activity. Physiological parameters of NDVI, SPAD and seed cotton yield significantly increased in FM treated soils compared to CF applications. The increase in cotton yield was 29.15%, in NDVI value was 22.38% and in SPAD value was 121.7%. The main issues with cotton in the area are the low organic carbon content of the soils, high clay content, arid and semi-arid soils, and their detrimental impact on the uptake of particular nutrients (N, P and B).

Hydrocyclone combines with alkali-thermal pretreatment to enhance short-chain fatty acids production from anaerobic fermentation of waste activated sludge

The production of short-chain fatty acids (SCFAs) through anaerobic fermentation of waste activated sludge (WAS) is commonly constrained by limited substrate availability, particularly for WAS with low organic content. Combining the hydrocyclone (HC) selection with alkali-thermal (AT) pretreatment is a promising solution to address this limitation. The results indicated that HC selection modified the sludge properties by enhancing the ratio of mixed liquid volatile suspended solids (MLVSS)/mixed liquid suspended solids (MLSS) by 19.0% and decreasing the mean particle size by 17.4%, which were beneficial for the subsequent anaerobic fermentation process. Under the optimal HC + AT condition, the peak value of SCFAs production reached 4951.9 mg COD/L, representing a 23.2% increase compared to the raw sludge with only AT pretreatment. Mechanism investigations revealed such enhancement beyond mechanical separation. It involved an increase in bound extracellular polymeric substances (EPS) through HC selection and the disruption of sludge spatial structure by AT pretreatment. Consequently, this combination pretreatment accelerated the transfer of particulate organics (i.e., bound EPS and intracellular components) to the supernatant, thus increasing the accessibility of WAS substrate to hydrolytic and acidifying bacteria. Furthermore, the microbial structure was altered with the enrichment of key functional microorganisms, probably due to the facilitation of substrate biotransformation and product output. Meanwhile, the activity of hydrolases and SCFAs-forming enzymes increased, while that of methanogenic enzymes decreased. Overall, this strategy successfully enhanced SCFAs production from WAS while reducing the environmental risks of WAS disposal.

Vineyard cover crop management strategies and their effect on soil properties across Europe

AbstractVineyard soils are often of inherently poor quality with low organic carbon content. Management can improve soil properties and thus soil fertility. In European wine‐growing regions, a broad range of inter‐row management strategies evolved based on specific local site conditions and the varying effects of management intensities on soil, water balance, yield and grape quality. Accordingly, there is a need to investigate the effects of locally common cover crop management strategies and tillage intensity on soil organic carbon content and soil physical parameters. In this study, we investigated the impact of the most common inter‐row management practices in Austria, France, Romania and Spain. In all countries, we compared paired sites. Each site with cover crops and inter‐row management of low intensity was compared with one site with (temporarily) bare soil and high management intensity. All studied sites with cover crops and low management intensity, except those in Spain, had higher organic carbon contents than the paired more intensively managed vineyards. However, the highly water‐limited Spanish vineyards with temporary cover crops had lower organic carbon contents than the paired sites with bare soil. Sites with more organic carbon had better results for bulk density, percolation stability (PS), hydraulic conductivity and available soil water, with soil hydraulic parameters being less pronounced than others. Country comparison of inter‐row weed control systems showed that PS was particularly low in sampled vineyards in Romania and Spain, where weed control is based on intensive mechanical tillage. Alternating management systems with tillage every second inter‐row showed a decrease in soil structure compared with permanent green cover. Thus, inter‐row management with cover crops and reduced tillage increases soil organic carbon content and improves soil structure compared with bare soil management. If local constraints, such as water scarcity, do not allow year‐round planting, alternating inter‐row management with several years of alternating periods may be an option to mitigate those adverse effects. However, negative impact on the soil structure occurs with the very first tillage operation, whereas negative effects on the carbon balance only appear after long‐term use of tillage.

Generation, characterization, and toxicological assessment of reference ultrafine soot particles with different organic content for inhalation toxicological studies

Ultrafine particles (UFP) are the smallest atmospheric particulate matter linked to air pollution-related diseases. The extent to which UFP's physical and chemical properties contribute to its toxicity remains unclear. It is hypothesized that UFP act as carriers for chemicals that drive biological responses. This study explores robust methods for generating reference UFP to understand these mechanisms and perform toxicological tests.Two types of combustion-related UFP with similar elemental carbon cores and physical properties but different organic loads were generated and characterized. Human alveolar epithelial cells were exposed to these UFP at the air-liquid interface, and several toxicological endpoints were measured. UFP were generated using a miniCAST under fuel-rich conditions and immediately diluted to minimize agglomeration. A catalytic stripper and charcoal denuder removed volatile gases and semi-volatile particles from the surface. By adjusting the temperature of the catalytic stripper, UFP with high and low organic content was produced.These reference particles exhibited fractal structures with high reproducibility and stability over a year, maintaining similar mass and number concentrations (100 μg/m3, 2.0·105 #/cm3) and a mean particle diameter of about 40 nm. High organic content UFP had significant PAH levels, with benzo[a]pyrene at 0.2 % (m/m). Toxicological evaluations revealed that both UFP types similarly affected cytotoxicity and cell viability, regardless of organic load. Higher xenobiotic metabolism was noted for PAH-rich UFP, while reactive oxidation markers increased when semi-volatiles were stripped off. Both UFP types caused DNA strand breaks, but only the high organic content UFP induced DNA oxidation.This methodology allows modification of UFP's chemical properties while maintaining comparable physical properties, linking these variations to biological responses.

Efficacy of nitrogen and Azolla spp. on growth and yield of black rice (Oryza sativa L.)

An experimental field study was carried out in the Kharif season of 2023 at the Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P.). The experimental replications were conducted using a Randomized Block Design, with three levels of Nitrogen (0, 60, 90kg N/ha) and Azolla spp. (2, 4, 6t/ha), and one Control (NPK 120:60:60 kg/ha). In all, there were a total of ten treatments, each reproduced three times. The tested field had sandy loam soil texture with a neutral soil pH of 7.6, low organic carbon content of 0.372%, nitrogen content of 278.4 kg/ha, phosphorous content of 29.5 kg/ha, and potassium level of 217.3 kg/ha. The experimental results showed that treatment T₉ obtained significantly higher plant height (107.77 cm), dry weight (66.05 g), crop growth rate (57.27 g/m2/day), relative growth rate (0.0279 g/g/day), highest number of tillers per hill (22.07), panicles per m2 (282), test weight (15.23 g), grain yield (3.67 t/ha), stover yield (6.7 t/ha), and harvest index (35.74%). Transplanted Black Rice of variety BPT-2841 exhibited significantly greater maximum gross return (1,80,551.40 INR/ha), net return (1,05,496.30 INR/ha), and B:C ratio (1.41) in treatment T9. The investigation concludes that Nitrogen, being easily transportable in soil and plants, is a constituent of amino acids, nucleic acids, chlorophyll, enzymes, and hormones. These factors are essential in plant physiology and are associated with increased tillering, biomass production, protein synthesis, grain filling, yield, and quality. The availability, absorption, and utilization of nitrogen have a significant impact on these processes. Therefore, in the present experiment, the nitrogen requirements are met by applying 90kg of nitrogen through urea combined with 6t/ha of Azolla spp. This approach revealed superior performance in terms of both crop yield and economic returns .