Composition Of Oil Research Articles

The Composition, Antioxidant and Antibacterial Activity of Essential Oils from Five Species of the Magnoliaceae Family.

The leaves of Magnoliaceae family plants contain abundant essential oils (EOs), and these species can be used in many fields due to their high industrial, medicinal, and ornamental values. This study aims to identify the main compounds of the EOs from the leaves of five common Magnoliaceae species (Michelia maudiae, Michelia hedyosperma, Michelia macclurei, Manglietia lucida, Manglietia conifer) using hydrodistillation, GC-MS analysis, and in vitro tests. Additionally, the antioxidant and antibacterial activities of the EOs were also evaluated. The results show that 151 compounds were identified across five species, with sesquiterpenes being dominant. Some key compounds (such as β-caryophyllene, δ-amorphene, β-guaiene, globulol, and β-acorenol) were common among all the species, highlighting their crucial roles in plant physiology and resilience. Other compounds (like valeranone and nerolidol in M. maudiae and β-elemene in M. macclurei) were specific, indicating different functions. Among the five species, the essential oil of M. macclurei contains β-elemene and nerolidyl acetate, and it has the weakest antioxidant activity (IC50 value: 2918.61~21,341.98 μg/mL) but the strongest antibacterial activity (inhibition zone diameter: 8.55 ± 0.93~22.92 ± 0.46 mm; LC50 value: 0.02~0.78 mg/mL). Meanwhile, the EO of M. maudiae demonstrated the best antioxidant activity (the IC50 value was 1283.58~6258.32 μg/mL) and the second-best antibacterial activity (the inhibition zone diameter ranged from 7.61 ± 0.02 to 26.92 ± 0.46 mm, and the LC50 value was 0.03~2.28 mg/mL). Overall, the EO of M. maudiae had the best comprehensive performance. Therefore, the EOs of M. macclurei and M. maudiae showed different performances in biological activity categories, and they could be developed and used in different fields, with the possibility of discovering new applications. This brings inspiration to the potential commercial and industrial uses of sesquiterpenes in Magnoliaceae.

Major Sesquiterpenoids in Psychotria laui Leaf Essential oil Exhibit Anti-Inflammatory and Cytotoxic Properties

Objective: This study aims to investigate the chemical constituents and biological properties of the essential oil derived from Psychotria laui, a plant recognized for its medicinal applications, particularly in traditional Vietnamese medicine, where it is utilized for the treatment of digestive and inflammatory disorders. Methods: Fresh leaves of Psychotria laui were gathered in Quangtri, Vietnam, and subjected to hydro-distillation using a Clevenger-type apparatus to obtain the essential oil. The chemical composition of the essential oil was analyzed by gas chromatography-mass spectrometry (GC-MS). The antioxidant potential was measured using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay, while the inhibition of nitric oxide production was tested in lipopolysaccharide-stimulated RAW264.7 cells. Cytotoxicity against the SK-LU-1 cell line (human lung adenocarcinoma) was evaluated using the sulforhodamine B (SRB) assay. Results: The essential oil from Psychotria laui contained 78 distinct constituents. The major compounds identified were spathulenol (10.4%), thujopsan-2- α-ol (9.5%), 7- epi- α-eudesmol (6.5%), 14-hydroxy-9- epi-( E)-caryophyllene (4.4%), epi- α-cadinol (3.9%), α-muurolol (3.8%), 1- epi-cubenol (3.5%), and δ-cadinene (3.2%). The essential oil showed no antioxidant activity, with an IC50 (half-maximal inhibitory concentration) value greater than 500 µg/mL, in contrast to the positive control, L-ascorbic acid, which had an IC50 of 7.78 ± 0.39 µg/mL in the DPPH assay. However, its anti-inflammatory activity was evident by its ability to inhibit nitric oxide production, with an IC50 of 19.48 ± 1.53 µg/mL in lipopolysaccharide-stimulated RAW264.7 macrophages. Moreover, the essential oil exhibited potent cytotoxicity against the SK-LU-1 cancer cell line, with an IC50 of 8.49 ± 0.73 µg/mL in the SRB assay. Conclusion: The essential oil from Psychotria laui leaves contains numerous bioactive compounds and exhibits significant anti-inflammatory and cytotoxic properties, although it lacks antioxidant activity.

Effect of granite powder on the strength, durability and sustainability of soil treated using steel slag or cement

Granite powder, a byproduct of granite quarrying, enhances the long-term strength of cement-treated soil due to its pozzolanic reactivity. However, its effects on early strength and seawater durability, as well as its influence on slag-treated soils, remain unexplored. We studied cement-treated and slag-treated soil composites with 0% and 30% granite powder, using 8% cement or 30% steel slag per dry soil mass. We performed vane shear and unconfined compressive strength (UCS) tests at 1, 3, 6, 12hours, and 1, 3, 7, 28, 63, 91, 119 days. After 28 days of air curing, samples endured seawater exposure at 30°C for 0, 28, 63, and 91 days, followed by UCS and XRF calcium composition tests. Seawater samples were also analyzed for calcium and magnesium concentrations using a photometer. Despite similar dry unit weights, slag-treated soil initially exhibited lower strength than cement-treated soil. However, granite powder enabled slag-treated samples to reach comparable strength levels to those of cement-treated soil. Its pozzolanic reactivity facilitated self-repair in samples affected by seawater-induced calcium depletion, while also reducing emissions, resource consumption, and construction costs associated with treated soil materials.

Fatty acid composition and anti-cancer activity of essential oil from Tenebrio molitor larvae in combination with zoledronic acid on prostate cancer

The essential oil extracted from Tenebrio molitor larvae (EOTM) is a natural product containing trace elements with potential therapeutic properties. This study aimed to assess the anticancer effects of EOTM and its synergistic interactions with zoledronic acid, a bisphosphonate drug, on prostate cancer cell lines. The chemical composition of EOTM was analyzed using GC-MS revealing a high concentration of fatty acids. The cytotoxicity of EOTM, both as a standalone treatment and in combination with zoledronic acid, was evaluated on prostate cancer cell lines (LNCaP, PC3) and normal hSKM using MTT assays. Results demonstrated that EOTM exhibited selective toxicity, inhibiting the growth of cancer cells in a dose-dependent manner while sparing normal cells. Morphological assessments and gene expression analyses of BCL2 and BAX were conducted through microscopy, Western blotting, and real-time RT-qPCR. These analyses indicated that EOTM induced apoptosis in cancer cells, as evidenced by cellular shrinkage, membrane blebbing, and nuclear fragmentation. Western blot results showed that EOTM downregulated the anti-apoptotic protein BCL2 and upregulated the proapoptotic protein BAX, suggesting activation of apoptosis pathways. Additionally, the combination of EOTM with zoledronic acid amplified these effects. Hoechst 33258 staining further confirmed the purity of cells following treatment. In conclusion, EOTM exhibits strong anticancer properties by inducing apoptosis in prostate cancer cells and demonstrates synergistic potential when combined with zoledronic acid. These findings warrant further investigation of EOTM as a natural and effective cancer treatment option.

Developing Lignin/Pva- Tea Tree Oil Composites for Enhanced Antibacterial and Antifungal Properties

Developing Lignin/Pva- Tea Tree Oil Composites for Enhanced Antibacterial and Antifungal Properties

Advances in Soybean Genetic Improvement.

The soybean (Glycine max) is a globally important crop due to its high protein and oil content, which serves as a key resource for human and animal nutrition, as well as bioenergy production. This review assesses recent advancements in soybean genetic improvement by conducting an extensive literature analysis focusing on enhancing resistance to biotic and abiotic stresses, improving nutritional profiles, and optimizing yield. We also describe the progress in breeding techniques, including traditional approaches, marker-assisted selection, and biotechnological innovations such as genetic engineering and genome editing. The development of transgenic soybean cultivars through Agrobacterium-mediated transformation and biolistic methods aims to introduce traits such as herbicide resistance, pest tolerance, and improved oil composition. However, challenges remain, particularly with respect to genotype recalcitrance to transformation, plant regeneration, and regulatory hurdles. In addition, we examined how wild soybean germplasm and polyploidy contribute to expanding genetic diversity as well as the influence of epigenetic processes and microbiome on stress tolerance. These genetic innovations are crucial for addressing the increasing global demand for soybeans, while mitigating the effects of climate change and environmental stressors. The integration of molecular breeding strategies with sustainable agricultural practices offers a pathway for developing more resilient and productive soybean varieties, thereby contributing to global food security and agricultural sustainability.

The Influence of Altitude on the Polyphenols Content and Antioxidant Capacity of Northern Moroccan 'Dellahia' Prickly Pear Juice

Moroccan cactus exhibits high genetic variability with several cultivars. The 'Dellahia' prickly pear variety, prevalent in northern Morocco and noted for its green pulp, is among the least valued cactus varieties, primarily consumed fresh. This study aimed to assess the impact of altitude on total phenolic acids and flavonoid content (TPC and TFC) and the antioxidant activity of 'Dellahia' prickly pear juice from northern Morocco. Significant differences in TPC ranged from 91.29 to 130.45 mg GAE/Kg of juice from the Mestassa and Wahran sites (at 119 m and 482 m altitude, respectively). TFC also varied slightly, from 18.8 to 19.1 mg RE/Kg of juice. Variations in antioxidant activity were evident in both DPPH• and ABTS+ assays, with DPPH• inhibition percentages ranging from 8.85% to 19.14% and ABTS+ inhibition from 41.07% to 54.35%. However, the influence of altitude on these parameters was inconclusive, as samples from higher altitudes did not consistently yield lower or higher values. Other factors such as soil composition, sunlight, and farming practices may influence these results.

The Impact of Selected Eutectic Solvents on the Volatile Composition of Citrus lemon Essential Oil.

The development of new materials for the controlled release of molecules represents a topic of primary importance in medicine, as well as in food science. In recent years, eutectic solvents have been applied as releasing media due to their improved capacity to interact with specific molecules, offering a broad range of tunability. Nevertheless, their application in essential oil dissolution are rare and more data are needed to develop new generations of effective systems. Herein, three eutectic systems, respectively, composed of choline chloride and ethylene glycol (1:2 molar ratio), methyltriphenylphosphonium bromide and ethylene glycol (molar ratio 1:5), and choline chloride and glycerol (molar ratio 1:1.5) were tested as materials for the controlled release of an essential oil derived from Citrus lemon leaves. Through static headspace fractionation, followed by gas chromatographic analysis, the performances of the three systems were assessed. The specific composition of DESs was pivotal in determining the releasing polar molecules as aldehydes and alcohols. A sustainability ranking based on the EcoScale tool highlighted the superior characteristics of the choline chloride-glycerol DES.

Comparison of plant microbiota in diseased and healthy rice reveals methylobacteria as health signatures with biocontrol capabilities.

Rice (Oryza sativa) is a staple food worldwide, but its production is under constant pressure from both abiotic and biotic stresses, resulting in high use of agrochemicals. The plant microbiome harbours microorganisms that can benefit plant health and provide alternatives to the use of agrochemicals. The composition of plant microbiomes depends on many factors (soil composition, age, and health) and is considered a primary driver of future plant health. To identify plant microbiomes that protect against disease, we hypothesised that asymptomatic rice plants in fields under high pathogen pressure (i.e., healthy islands of plants among predominantly diseased plants) might harbour a microbiota that protects them from disease. We sampled healthy and leaf-diseased plants in rice fields with high disease incidence in Cambodia and profiled their microbiota at leaf, root, and rhizosphere levels using 16S V3V4 and 18S V4 amplicon barcoding sequencing. Comparison of amplicon sequence variants (ASV) of the microbiota of healthy and diseased samples revealed both disease and healthy signatures (significant enrichment or depletion at ASV/species/genus level) in both fields. The genera Methylobacterium and Methylorubrum were identified health taxa signatures with several species significantly enriched in healthy leaf samples (Methylobacterium indicum, Methylobacterium komagatae, Methylobacterium aerolatum, and Methylorubrum rhodinum). A cultivation approach on rice samples led to the isolation of bacterial strains of these two genera, which were further tested as bioinoculants on rice leaves under controlled conditions, showing for some of them a significant reduction (up to 77%) in symptoms induced by Xanthomonas oryzae pv. oryzae infection. We validated the hypothesis that healthy plants in fields under high disease occurrence can host specific microbiota with biocontrol capacities. This strategy could help identify new microbes with biocontrol potential for sustainable rice production.

Martian buildings: Feasible cement/concrete for onsite sustainable construction from the structural point of view

Colonizing other planets, like Mars, marks a significant milestone in the pursuit of a multi-planetary existence. Millions of people would settle on Mars in self-sufficient bases. Colonizing Mars is a long-term mission that demands self-sufficient, secure habitats and comprehensive planning. Importing structures, such as inflatable structures, from Earth is cost-prohibitive, making the utilization of in-situ resources and onsite construction the most viable approach for preparing the required buildings. Studies have shown that it is possible to produce and craft several kinds of binders and concretes with appropriate mechanical behavior using Martian soil composition; however, determining the optimal option for onsite construction remains a challenge. This study investigates available cement/concrete options for onsite construction on Mars from a structural engineering perspective, taking into account the available resources and technologies. In this regard, the observations and data provided by Martian landers, rovers, orbiters and methods such as Viking-1 & 2, Pathfinder, Spirit, Opportunity, Curiosity, Mars Express, Ultraviolet–visible/Near-infrared reflectivity spectra and Alpha particle X-ray spectrometer were used to obtain a comprehensive and detailed investigation. Eleven types of Martian cement/concrete based on the in-situ resources, soil composition, and available technologies were compared based on the criteria and indices defined in accordance with the structural engineering point of view to select the best practical option for onsite construction. These criteria encompass factors such as mechanical behavior, Martian structural loads, raw material accessibility, available sources, energy required for production, water requirement, curing and hardening time, possibility of using 3D printers, byproduct usefulness, conditions required for hardening and curing, importation requirements from Earth, production complexity, long-term durability and behavior under galactic cosmic rays (GCRs) and solar energetic particles (SEPs). The pros and cons of each cement/concrete option are thoroughly assessed, considering the harsh conditions on Mars. Additionally, the study highlights extra considerations that are crucial for onsite construction on Mars. To determine the best practical option for onsite construction and sustainable colonization, the proposed cements/concretes were compared using multi-scale spider/radar diagrams and a quantitative point of view. This perspective was enabled by assigning weights to each criterion through expert consultation, experimental data, and literature review, ensuring that the diagrams accurately reflect the features of each concrete mix. This comprehensive investigation aims to provide valuable insights into selecting the most suitable cement/concrete for onsite construction on Mars, considering the structural engineering perspective and the long-term goal of sustainable colonization.

Antimycobacterial Activity of Essential Oils from Bulgarian Rosa Species Against Phylogenomically Different Mycobacterium tuberculosis Strains

In this study, we aimed to assess the activity of the essential oils from four Bulgarian oil-bearing roses Rosa damascena Mill., R. alba L., R. centifolia L., and R. gallica L., on the reference strain Mycobacterium tuberculosis H37Rv and clinical M. tuberculosis strains of the Beijing and Latin-American Mediterraneum genotypes. The chemical composition of the essential oils was determined by gas chromatography (GC-FID/MS). Minimal inhibitory concentrations (MIC) were determined using the resazurin method. R. alba oil showed the highest inhibitory activity when tested on all strains of different phylogenetic origins with MIC in the range of 0.16–0.31 mg/mL, while R. gallica oil was the least active (MIC 0.62–1.25 mg/mL). The obtained results show heterogeneity of rose oil action on different mycobacterial strains and we hypothesize that the combined level of geraniol and nerol is a key factor that underlies the antimycobacterial action of the rose oils. Strain Beijing 396 was relatively more susceptible to the rose oils probably due to multiple and likely deleterious mutations in its efflux pump genes. Two clinical MDR strains have likely developed during their previous adaptation to anti-TB drugs certain drug tolerance mechanisms that also permitted them to demonstrate intrinsic tolerance to the essential oils. Further research should investigate a possible synergistic action of the new-generation anti-TB drugs and the most promising rose oil extracts on the large panel of different strains.

Optimizing Olive Production: The Role of Foliar Fertilizers in Boosting Yield and Quality

To enhance yield and produce high-quality olive products, it is crucial to implement accurate and balanced fertilization programs. Like other crops, olive trees require the application of specific macro and micronutrients in addition to basic fertilization. This study aimed to evaluate the effects of foliar fertilizer applications containing K as well as N, K, Ca, and B, in addition to basic fertilization, on the yield and quality parameters of the Gemlik olive (Olea europaea L. cv. Gemlik) variety, known for its high economic value and use in black table olives and oil production, during two consecutive seasons in 2021–2022. The research evaluated the effects on olive fruit yield, fruit nutrient content (N, Ca, P, Na, K, Mg, Zn, Fe, Cu, and Mn), oil yield, and quality. In addition to traditional basic fertilization (NPK fertilizer), foliar fertilizers containing K as well as N, K, Ca, and B nutrients were applied before flowering and after fruit set. These applications were organized using a randomized block design with three replicates, each consisting of three trees. The results showed that foliar fertilizer applications, in addition to basic fertilization, had a significant impact on the yield and quality parameters. Specifically, foliar K applications positively affected olive yield in the second year. Moreover, foliar fertilizer applications improved the fruit nutrient content, oil quality (K-232, K-270, peroxide, acidity, and total phenol), and oil composition (%). Therefore, it is recommended that foliar fertilizers are applied during similar periods under similar conditions. However, ensuring the continuity of an optimal fertilization management plan is crucial for olive, as it is a perennial plant.

Revolutionizing Precision Agriculture: Advanced Seed Prescription Generation and Cloud Infrastructure

This article explores the revolutionary impact of advanced seed prescription generation engines and cloud infrastructure on precision agriculture. It delves into the technical intricacies of enhancing seed prescription systems through cutting-edge data pipelines and scalable cloud platforms. The article discusses how these sophisticated systems analyze various factors such as soil composition, topography, historical yield data, and climate patterns to determine optimal seeding rates and patterns with unprecedented accuracy. It highlights the challenges faced in implementing these systems, including scalability, data processing, reliability, and monitoring, and presents innovative cloud-based solutions to address these issues. The benefits of these advancements, including improved efficiency, enhanced accuracy, scalability, reliability, and cost-effectiveness, are examined, along with their potential to reshape the global food production landscape and promote sustainable farming practices.

Geo Spatial Assessment and Micronutrient Mapping of Calcareous Soils in Muzaffarpur District, Bihar, India

The soil fertility maps created using GIS are valuable tools, with the geo-coordinates of soil samples recorded using a Garmin GPS device and then imported into the base map through ArcGIS software. The analyzed soil fertility data covers sampling sites in the Minapur, Kanti, and Marwan blocks of Muzaffarpur district, Bihar. A total of 40 geo-referenced composite soil samples were collected from various locations, with multiple soil fertility parameters assessed using standard prescribed methods. The results indicated that the soil had an alkaline reaction, with a pH value above 7.5. The soil organic content ranged from low to medium. DTPA-extractable available zinc (Zn) levels varied between 0.14 and 0.79 ppm, with an average of 0.42 ppm. Copper (Cu) levels were below the critical limits, while iron (Fe) and manganese (Mn) were found in relatively medium concentrations.

ANTIOXIDANT AND CYTOTOXIC EFFECTS OF ESSENTIAL OILS EXTRACTED FROM Viola odorata L. CULTIVATED IN IRAQ

This study was aimed to determine the composition of essential oil contained in Viola odorata flowers and leaves. As well as assessing the cytotoxic effects of this oil on cancer cells and its antioxidant properties. A GC-Mass analysis was conducted to reveal essential oil components in flowers and leaves. For testing the antioxidant capacity of flowers and leaves oil, DPPH (1,1 Dyphenyl-2-picrylhydrazyl), resazurin dye, and hydroxyl were used. An in vitro study was conducted using lung cancer (A549) and breast normal (MCF-10) cell lines with concentrations of 25, 50, 100, 200, and 300 µl/ml of V. odorata L. essential oil. According to the results, essential oils derived from flowers and leaves contain different components in terms of quality and quantity. At a concentration of 300 µl/ml, the results showed that flowers' essential oil was highly antioxidant (98.16 %, 92.47%, 94.00 %) when combined with DPPH, resazurin dye, and hydroxyl, respectively. There was variation in cytotoxic effects on cancer cells based on oil concentrations and sources (flowers and leaves). In conclusion, the A549 cell line was significantly affected by flower oil than by leaves oil. The highest effect of flower oil was observed at a concentration of 300 µl/ml.

Optimization of antimicrobial properties of essential oils under rotating magnetic field

Essential oils (EOs) extracted from Thymus vulgaris L. (TEO) and Rosmarinus officinalis L. (REO) have aroused interest in their application to food preservation or in alternative medicine or aroma-therapy. In this study, the chemical compositions of essential oils were determined and analyzed. The purpose of the investigation was to investigate in detail the activity of essential oils extracted from herbs (thyme and rosemary) and exposed to rotating magnetic filed (RMF) against the model Gram-negative bacteria Escherichia coli The bacterial removal has been optimized by a surface response methodology (RSM). It was shown that TEO in a concentration of 10 µL/50 mL of water resulted in a total bacterial number reduction after 40 min under the RMF. Rosemary's antibacterial effect was much weaker. Thus, we summarized that the rotating magnetic fields at a frequency of 27 Hz can increase the antimicrobial efficiency but the effect depends on the type of essential oil. High-rate bacteria removal was obtain for thyme oil in concentration of 30 µL of thyme oil to 50 mL of bacterial suspension, exposed to RMF at a frequency of 27 Hz for 40–60 min.

Essential Oils from the Leaves and Stem Barks of Pluchea Indica (L.) Less.: Chemical Analysis, Cytotoxicity, Anti-inflammation, Antimicrobial Activity, Molecular Docking, and ADMET Profiling.

Pluchea indica (L.) Less. is a medicinal plant native to Asia. Traditionally, it is known for numerous traditional uses, such as treatments for fever, cough, and digestive issues. The present investigation aims to determine the chemical compositions of essential oils from its fresh leaves and stem barks. By using hydro-distillation and the GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry) analysis, the studied samples were dominated by sesquiterpene hydrocarbons (76.8-82.2 %) and their oxygenated derivatives (8.4-19.0 %). β-Selinene (42.0-43.5 %) and silphinene (21.1-22.9 %) were the main compounds. Significantly, the stem bark essential oil strongly monitored the growth of four cancer cell lines K562, HeLa, HepG2, and MCF-7 with IC50 values of 2.89-7.34 μg/mL. Both studied samples showed strong anti-inflammatory activity against NO (nitric oxide) production with IC50 values of 21.81-23.18 μg/mL. The studied sample also exhibited antimicrobial activity at different levels. The molecular docking study revealed that β-selinene exhibited the strongest binding affinity for all four cancer-related protein targets: epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), Abelson tyrosine-protein kinase 1 (ABL1), and phosphatidylinositol 3-kinase (PI3 K-α). The ADMET profiles of the major compounds were also predicted to provide insights for further research considerations.

Insight into Chemical Composition and Anti-inflammatory Activities of Essential Oil from Flowers, Leaves and Vine Stems of Cissampelopsis volubilis Miq.

Insight into Chemical Composition and Anti-inflammatory Activities of Essential Oil from Flowers, Leaves and Vine Stems of Cissampelopsis volubilis Miq.

Soil microbial community composition by crop type under rotation diversification

BackgroundCrop rotation is an important agricultural practice that often affects the metabolic processes of soil microorganisms through the composition and combination of crops, thereby altering nutrient cycling and supply to the soil. Although the benefits of crop rotation have been extensively discussed, the effects and mechanisms of different crop combinations on the soil microbial community structure in specific environments still need to be analyzed in detail.Materials and methodsIn this study, six crop rotation systems were selected, for which the spring crops were mainly tobacco or gramineous crops: AT (asparagus lettuce and tobacco rotation), BT (broad bean and tobacco rotation), OT (oilseed rape and tobacco rotation), AM (asparagus lettuce and maize rotation), BM (broad bean and maize rotation), and OR (oilseed rape and rice rotation). All crops had been cultivated for > 10 years. Soil samples were collected when the rotation was completed in spring, after which the soil properties, composition, and functions of bacterial and fungal communities were analyzed.ResultsThe results indicate that spring cultivated crops play a more dominant role in the crop rotation systems than do autumn cultivated crops. Crop rotation systems with the same spring crops have similar soil properties and microbial community compositions. pH and AK are the most important factors driving microbial community changes, and bacteria are more sensitive to environmental responses than fungi. Rotation using tobacco systems led to soil acidification and a decrease in microbial diversity, while the number of biomarkers and taxonomic indicator species differed between rotation patterns. Symbiotic network analysis revealed that the network complexity of OT and BM was the highest, and that the network density of tobacco systems was lower than that of gramineous systems.ConclusionsDifferent crop rotation combinations influence both soil microbial communities and soil nutrient conditions. The spring crops in the crop rotation systems had stronger dominating effects, and the soil bacteria were more sensitive than the fungi were to environmental changes. The tobacco rotation system can cause soil acidification and thereby affect soil sustainability, while the complexity of soil microbial networks is lower than that of gramineous systems. These results provide a reference for future sustainable applications of rotation crop systems.

2023: a soil odyssey–HeAted soiL-Monoliths (HAL-Ms) to examine the effect of heat emission from HVDC underground cables on plant growth

BackgroundThe use of renewable energy for sustainable and climate-neutral electricity production is increasing worldwide. High-voltage direct-current (HVDC) transmission via underground cables helps connect large production sides with consumer regions. In Germany, almost 5,000 km of new power line projects is planned, with an initial start date of 2038 or earlier. During transmission, heat is emitted to the surrounding soil, but the effects of the emitted heat on root growth and yield of the overlying crop plants remain uncertain and must be investigated.ResultsFor this purpose, we designed and constructed a low-cost large HeAted soiL-Monolith (HAL-M) model for simulating heat flow within soil with a natural composition and density. We could observe root growth, soil temperature and soil water content over an extended period. We performed a field trial-type experiment involving three-part crop rotation in a greenhouse. We showed that under the simulated conditions, heat emission could reduce the yield and root growth depending on the crop type and soil.ConclusionsThis experimental design could serve as a low-cost, fast and reliable standard for investigating thermal issues related to various soil compositions and types, precipitation regimes and crop plants affected by similar projects. Beyond our research question, the HAL-M technique could serve as a link between pot and field trials with the advantages of both approaches. This method could enrich many research areas with the aim of controlling natural soil and plant conditions.