Important Soil Research Articles

Hydrogels with Essential Oils: Recent Advances in Designs and Applications.

The innovative fusion of essential oils with hydrogel engineering offers an optimistic perspective for the design and development of next-generation materials incorporating natural bioactive compounds. This review provides a comprehensive overview of the latest advances in the use of hydrogels containing essential oils for biomedical, dental, cosmetic, food, food packaging, and restoration of cultural heritage applications. Polymeric sources, methods of obtaining, cross-linking techniques, and functional properties of hydrogels are discussed. The unique characteristics of polymer hydrogels containing bioactive agents are highlighted. These include biocompatibility, nontoxicity, effective antibacterial activity, control of the sustained and prolonged release of active substances, optimal porosity, and outstanding cytocompatibility. Additionally, the specific characteristics and distinctive properties of essential oils are explored, along with their extraction and encapsulation methods. The advantages and disadvantages of these methods are also discussed. We have considered limitations due to volatility, solubility, environmental factors, and stability. The importance of loading essential oils in hydrogels, their stability, and biological activity is analyzed. This review highlights through an in-depth analysis, the recent innovations, challenges, and future prospects of hydrogels encapsulated with essential oils and their potential for multiple applications including biomedicine, dentistry, cosmetics, food, food packaging, and cultural heritage conservation.

An in-depth study of anthocyanin synthesis in the exocarp of virescens and nigrescens oil palm: metabolomic and transcriptomic analysis.

Oil palm (Elaeis guineensis Jacq.) is a very important tropical woody oil plant with high commercial and ornamental value. The exocarp of the oil palm fruit is rich in anthocyanosides and proanthocyanidins, which not only give it a bright colour, but also mark the maturity of the fruit. The study of the dynamic change pattern of anthocyanoside content and important anthocyanoside metabolism-related regulatory genes during oil palm ripening is conducive to the improvement of the ornamental value of oil palm and the determination of the optimal harvesting period of the fruits. We analyzed the virescens oil palm (AS) and nigrescens oil palm (AT) at 95 days (AS1, AT1), 125 days (AS2, AT2) and 185 days (AS3, AT3) after pollination were used as experimental materials for determining the changes in the total amount of anthocyanins as well as their metabolomics and transcriptomics studies by using the LC-MS/MS technique and RNA-Seq technique. The results showed that the total anthocyanin content decreased significantly from AS1 (119µg/g) to AS3 (23µg/g), and from AT1 (1302µg/g) to AT3 (170µg/g), indicating a clear decreasing trend during fruit development. Among them, the higher flavonoids in AS and AT included anthocyanins such as peonidin-3-O-rutinoside (H35), pelargonidin-3-O-rutinoside (H21), and cyanidin-3-O-glucoside (H7), as well as condensed tannins such as procyanidin B2 (H47), procyanidin C1 (H49), and procyanidin B3 (H48). Notably, nine genes involved in the anthocyanin biosynthetic pathway exhibited up-regulated expression during the pre-development stage of oil palm fruits, particularly during the AS1 and AT1 periods. These genes include: Chalcone synthase (CHS; LOC105036364); Flavanone 3-hydroxylase (F3H; LOC105054663); Dihydroflavonol 4-reductase (DFR; LOC105040724, LOC105048473); Anthocyanidin synthase (ANS; LOC105035842), UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT; LOC105039612); Flavonoid 3',5'-hydroxylase (F3'5'H; LOC105036086, LOC105044124, LOC105045493). In contrast, five genes demonstrated up-regulated expression as the fruits developed, specifically during the AS3 and AT3 periods. These genes include: Chalcone synthase (CHS; LOC105036921, LOC105035716); Chalcone isomerase (CHI; LOC105045978); UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT; LOC105046326); Flavonoid 3'-hydroxylase (F3'H; LOC105036086). Most of differentially expressed genes exhibited up-regulation during the early stages of fruit development, which may contribute to the elevated anthocyanin content observed in oil palm fruits of both types during the pre-developmental period. Furthermore, the expression levels of most genes were found to be higher in the AT fruit type compared to the AS fruit type, suggesting that the differential expression of these genes may be a key factor underlying the differences in anthocyanoside production in the exocarp of oil palm fruits from these two fruit types. The findings of this study provide a theoretical foundation for the identification and characterization of genes involved in anthocyanin synthesis in oil palm fruits, as well as the development of novel variations using molecular biology approaches.

Revisiting the Nexus Between Oil Prices and Economic Activity for Asian Economies Using MIDAS

The objective of this paper is to re-examine the causal relationship between oil prices and economic activity for five Asian economies. We apply the unrestricted MIDAS (U-MIDAS) model using monthly data for real oil prices and quarterly data for real GDP for the period from 1998Q1 to 2019Q4. The causal nexus between oil prices and economic activity is also studied by means of wavelet analysis to investigate whether the relationship between the variables changes over different time scales. The key empirical results under the MIDAS approach show that there is a clear significant causal link from oil prices to economic activity, which is not as clearly found under the standard VAR approach. In addition, our results using impulse response functions suggest that the five Asian economies respond, in general, positively in economic activity to an oil price shock at shorter time horizons (less than two years), while the positive responses switch to mostly negative ones at longer time horizons (from two to four years). Our results, in general, support that the (theoretically) expected negative causal nexus between oil price fluctuations and economic activity for oil importers is dominant over longer time horizons for our dataset. An exception to this pattern is China, which has a dissimilar country profile in terms of its oil market and production structure from the profiles of the other Asian economies in the study. JEL Classification: C32, E32, O53, Q43

How does Russia's economy affect the region? Transmission channels and policy options

This paper studies how output fluctuations in Russia are transmitted internationally. Using dynamic panel models, the paper finds that Russia's output fluctuations are an important driver of output fluctuations of countries in the region, especially for oil importers, and are transmitted increasingly via trade and market confidence channels. The magnitude of cross-border spillovers is larger for countries with relatively high bilateral trade concentration, low export diversification, and weak external buffers. The paper also finds evidence that stronger public institutional quality- especially in the fiscal area- may help insulate countries from volatility in the Russian sovereign debt market.

The role of green ammonia in meeting challenges towards a sustainable development in China

The shift to a sustainable development has become an important issue in China. This paper discusses the role of green ammonia in promoting China's energy, environmental and economic sustainability which has not drawn enough attention. First, key challenges in China's energy transition, decarbonisation and regional sustainable development are explored. The coal-dominated energy consumption has placed great obstacles in achieving energy transition and led to massive CO2 emission since the large-scale industrialization. The high dependency on oil and gas import has threatened China's energy security. Imbalanced and unsustainable regional development is identified with data envelopment analysis. Second, the potential of green ammonia in meeting these challenges is analysed. Ammonia is examined to be a flexible and economic option for large-scale hydrogen transport and storage. Co-firing ammonia in coal power generation at 3 % rate is evaluated as an option for achieving low-carbon transition by 2030. Benefits of developing a green ammonia economy is discussed from energy, environmental and economic aspects. The practice can decline fossil energy consumption, enhance energy security, and facilitate renewable energy delivery and storage, industry decarbonisation, and regional development. We assume the findings and results contribute to addressing sustainability challenges and realizing a hydrogen economy in China.

Smirking in the energy market: Evidence from the Chinese crude oil options market

This study examines the implied volatility (IV) curve and its determinants in the newly established Chinese crude oil options market. Given China’s significant role as a crude oil importer and consumer, understanding this market’s dynamics is crucial for hedging and risk management. The paper identifies a left-skewed smirk in the IV curve, similar to major international options markets, indicating bearish market sentiment. The research analyzes various factors influencing the IV curve’s shape, with findings showing that market fear, measured by the put-to-call ratio (PCR), and the underlying asset’s volatility are primary determinants. The study also examines how the Russo-Ukrainian conflict heightened market fear and volatility, and we find with the onset of the conflict, it fostering optimistic view on the crude oil market. The analysis also highlights the significant impact of U.S. Federal interest rate hikes on the IV shape, emphasizing the inter-connectedness of global financial markets and the necessity for enhanced risk management strategies. These findings offer valuable insights for market participants and regulators regarding risk management in the Chinese crude oil options market.

A new method to estimate the soil freezing characteristic curve

The soil freezing characteristic curve (SFCC) defines the relationship between unfrozen water content and temperature. It is an important soil parameter in cold regions, but it is not easy to obtain, especially in the field. This paper proposes a method to indirectly estimate the SFCC for both fine-grained and coarse-grained soils by using the one-measurement SFCC method. From regression analysis, the parameters of the van Genuchten SFCC model can be expressed as functions of an adjustable parameter x. The SFCC of a soil sample contained three different zones, and sensitivity analysis indicated that the measured point in Zone 2 provided the most reliable SFCC estimation results. The proposed model and four widely acknowledged models were compared and evaluated with 33 fine-grained soils and 9 coarse-grained soils. The results showed that the proposed model provided the best estimation of the SFCC among the five models. This result also indicated that the proposed model provided a better estimation of the SFCC for fine-grained soils. This study provides a reliable approach to develop an SFCC estimation model with the one-measurement SFCC method.

Integrated transcriptome and endogenous hormone analyses reveal the factors affecting the yield of Camellia oleifera

Camellia oleifera is an important woody oil tree in China, in which the flowers and fruits appear during the same period. The endogenous hormone changes and transcription expression levels in different parts of the flower tissue (sepals, petals, stamens, and pistils), flower buds, leaves, and seeds of Changlin 23 high-yield (H), Changlin low-yield (L), and control (CK) C. oleifera groups were studied. The abscisic acid (ABA) content in the petals and stamens in the L group was significantly higher than that in the H and CK groups, which may be related to flower and fruit drops. The high N6-isopentenyladenine (iP) and indole acetic acid (IAA) contents in the flower buds may be associated with a high yield. Comparative transcriptome analysis showed that the protein phosphatase 2C (PP2C), jasmonate-zim-domain protein (JAZ), and WRKY-related differentially expressed genes (DEGs) may play an important role in determining leaf color. Gene set enrichment analysis (GSEA) comparison showed that jasmonic acid (JA) and cytokinin play an important role in determining the pistil of the H group. In this study, endogenous hormone and transcriptome analyses were carried out to identify the factors influencing the large yield difference in C. oleifera in the same year, which provides a theoretical basis for C. oleifera in the future.

Performance Evaluation of Linseed (<i>Linum usitatissimum</i> L.) Varieties in Buno Bedele Zone, South Western Oromia

Linseed (<i>Linum usitatissimum</i> L.) is one of the most important oil crops of Ethiopia and it is considered as the main food crop and the least expensive source of oil for the farmers in many highlands of the country. Even though numerous improved linseed varieties have been released in Ethiopia, the mean seed yield per unit area of the crop remains low due to poor access to improved varieties. To improve the crop’s production and productivity, testing the performance of improved linseed varieties in potential agro ecologies where the varieties have never been grown before is an essential activity. A study was carried out with the objective of testing the performance of improved linseed varieties and their genetic variability for seed yield and related traits in Bedele, Dabo Hana and Didesa districts of Buno Bedele zone, south western Oromia, Ethiopia. This experiment was carried out using twelve linseed varieties were used for investigation (Bekoji-14, Kassa-2, Welen, Bekoji, Kuma, Yadano, Furtu, Bakalcha, Dibane, Horesoba & Jitu) and one local check were sown in randomized complete block design with three replications during the 2022/2023 and 2023/2024 main cropping seasons. Six (6) quantitative morphological traits were collected and analyzed by using R-software accordingly. Combined analysis of data from the three locations revealed that there is significant difference among varieties for days to flowering, days to maturity and grain yield, but non-significant for plant height (cm), number of primary branches per plant and number of capsules per plant. Significant effect of location was observed in plant height, number of primary branch per plant, number of capsule per plant and grain yield however non-significant in days to flowering and days to maturity. The interaction of Variety X location was significant for days to flowering, days to maturity, plant height and grain yield, however non-significant for number of primary branch per plant and number of capsule per plant. The maximum seed yield was recorded in varieties Kuma (1588.9 kgha<sup>-1</sup>) followed by Beokoji-14 (1476.7 kgha<sup>-1</sup>) and the lowest yield (978.9 kg/ha-1) was obtained from local check. The combine AMMI analysis for seed yield across environments revealed significantly affected by environments that hold 26.6% of the total variation. The genotype and genotype by environmental interaction were significant and accounted for 12.40% and 19.42% respectively. Principal component 1 and 2 accounted for 10.78 % and 6.13% of the GEI respectively with a total of 16.91% variation. In general, Kuma and Bekoji-14 varieties were identified as the best varieties for yielding ability, stability and recommended in the area and with similar agro-ecologies.

Compacted Soil Liners and Covers for Waste Containment

An effective waste disposal system is essential in preventing the infiltration of leachate into the ground and achieving the sustainable development goal of ensuring access to clean and potable water. Liner is an important component of landfill in waste disposal facilities as it impedes the flow of leachate from the landfill. The choice of liner material depends on factors, such as the type and availability of soil, the site conditions, sustainability, and cost-effectiveness. This paper focuses on different soil types as compacted liners in waste containment facilities. The main purpose of this paper is to present the findings of laboratory investigations and measurements of hydraulic conductivity and other important soil properties extracted from previous literature with the aim of providing a guide in material selection for use as compacted soil liners and covers in waste containment applications. The key results of many laboratory studies previously conducted on soils of different properties, gradation, plasticity, and mineralogy, untreated or stabilized with various additives such as waste materials from industries, agricultural by-products and municipal waste materials are reported. The paper also presents the potential of using biopolymer-treated soils (soils modified by polymers) derived from plants and animals, as potential liner materials.

Spectrophotometric Determination of Biopolymers in Alabama Benchmark Soils

Biopolymers are organic polymers synthesized by biological organisms. Cellulose, lignin, and proteins are important soil biopolymers known to bind soil particles to improve or strengthen soil structures and support agricultural productivity. In this study, we spectrophotometrically determined the amount of soil cellulose, acetyl bromide lignin, and autoclaved citrate extractable protein in soils in relation to other soil properties. Results showed acetyl bromide lignin > cellulose > autoclaved citrate extractable protein. High clay soils have relatively higher amounts of cellulose and lignin but have lower protein content. The coefficient of variation (CV) of the three biopolymers in the soils studied was autoclaved citrate extractable protein (56.8%), >cellulose (55.2%), >acetyl bromide lignin (44.7%). Pearson correlation analysis showed that soil cellulose was significantly related to cation exchange capacity (CEC), total nitrogen, soil organic matter, and available phosphorus. An increase in soil acetyl bromide lignin suggested an increase in soil organic matter and lower soil available phosphorus. Soil autoclaved citrate extractable protein was significantly correlated with extractable acidity. However, cellulose, acetyl bromide lignin, and autoclaved citrate extractable protein were not significantly correlated with permanganate oxidizable carbon (POxC), electrical conductivity (EC), and C:N ratio. We assume that the concentrations of biopolymers in soils are an intrinsic soil characteristic and contribute to general soil health and productivity.

Transcriptome Analyses Reveal Differences in the Metabolic Pathways of the Essential Oil Principal Components of Different Cinnamomum Chemotypes

The genus Cinnamomum exhibits a rich variety of chemotypes and is an economically important essential oil (EO)-producing plant belonging to the family Lauraceae. Here, we aimed to explore the potential differences in the terpenoid (the principal components of EOs) biosynthesis pathways of different chemotypes at the molecular level in four Cinnamomum species—C. camphora var. linaloolifera, C. kanehirae, C. longipaniculatum, and C. micranthum. Gas chromatography–mass spectrometry (GC-MS) was employed to elucidate the discrepancies in the chemical profiles and compositions of leaf EO terpenoids among the four Cinnamomum species. The results revealed significant variations in leaf EO yields. The main constituents of the leaf EOs from C. camphora var. linaloolifera and C. kanehirae were the acyclic monoterpene linalool, and those of C. longipaniculatum and C. micranthum were the monoterpene eucalyptol and the sesquiterpene β-caryophyllene, respectively. Furthermore, a comparative transcriptome analysis of the leaves from the four Cinnamomum species revealed that differentially expressed genes (DEGs) were significantly enriched in terpene-related entries. Specifically, 42 and 24 DEGs were significantly enriched to the mevalonate (MVA)/2-methylerythritol 4-phosphate (MEP) pathways and terpene synthase (TPS) activity, respectively. Most genes encoding proteins involved in the terpenoid precursor MVA and MEP pathways exhibited differential expression across the four species, which correlated with the distinct terpenoid profiles observed in their leaf EOs. Four acyclic monoterpene linalool synthase genes—Maker00024100, Maker00014813, Maker00014818, and Maker00018424—were highly expressed in C. camphora var. linaloolifera and C. kanehirae. A monoterpene eucalyptol synthesis gene, Maker00001509, was highly expressed in C. longipaniculatum, and a sesquiterpene β-stigmasterol synthesis gene, Maker00005791, was highly expressed in C. micranthum. These expression levels were subsequently validated through quantitative real-time polymerase chain reaction (qRT-PCR). In conclusion, the combined results of the GC-MS and transcriptome analyses revealed a strong correlation between the metabolite content of the EOs and gene expression. This research contributes to a better understanding of the differences in terpene accumulation in various chemotypes of Cinnamomum at the molecular and mechanistic levels, laying a solid foundation for the cultivation of an ideal Cinnamomum variety.

Discharge Experiment and Structure Optimisation Simulation of Impulse Sound Source

The wave frequency and energy of traditional piezoelectric emission sources used in acoustic logging are limited, which results in an inadequate detection resolution for measuring small-scale geological formations. Additionally, the propagation of these waves in formations is prone to loss and noise interference, restricting detection to only a few tens of meters around the well. This paper investigates an impulse sound source, a new emission source that can effectively enhance the frequency range and wave energy of traditional sources by generating excitation waves through high-voltage discharges in a fluid-penetrated electrode structure. Firstly, a high-voltage circuit experimental system for the impulse sound source was constructed, and the discharge and response characteristics were experimentally analyzed. Then, four types of needle series electrode structure models were developed to investigate and compare the effects of different electrode structures on the impulse sound source, with the needle-ring electrode demonstrating superior performance. Finally, the needle-ring electrode structure was optimized to develop a ball-tipped needle-ring electrode, which is more suitable for acoustic logging. The results show that the electrode structure directly influences the discharge characteristics of the impulse sound source. After comparison and optimization, the final ball-tipped needle-ring electrode exhibited a broader frequency range—from zero to several hundred thousand Hz—while maintaining a high acoustic amplitude. It has the capability to detect geological areas beyond 100 m and is effective for evaluating micro-fractures and small fracture blocks near wells that require high detection accuracy. This is of significant importance in oil, gas, new energy, and other drilling fields.

Biochar improves morpho-physiological growth, osmolyte accumulation, nutrients balance, anti-oxidative defense and oil productivity of Brassica under flooding stress

Soil flooding is a serious abiotic stress that can repress plant growth and yield. The intensity of flooding stress is continuously increasing owing to rapid climate change and changes in rain intensity and frequency. Biochar (BC) emerges as an important soil amendment to mitigate adverse impacts of abiotic stress. The role of BC against different stresses is well reported, however, its role under flooding stress is not determined yet. Thus, this experiment was conducted to determine the role of BC on the performance of brassica crops under flooding stress. The experiment was comprised of well-watered (WW) and flooding stress (FS) conditions and biochar application: control, 1% biochar, and 2.5% biochar. The results indicated that flooding stress stunted the plant growth and impaired the photosynthetic pigments, leaf water status, osmolytes yield and yield traits, and oil concentration and increased the electrolyte leakage (EL), hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentration. The application of BC at the rate of 2.5% mitigated the adverse impacts of salinity and upgraded the antioxidant activities (~50-120%), reduced the oxidative stress markets (~70-300%), and increased the leaf water status, photosynthetic pigments, osmolyte accumulation, nutrient uptake, yield traits, and oil contents. In conclusion, BC application can improve the productivity and oil yield of brassica under drought stress by improving plant physiological and biochemical functioning. However, more in depth studies are direly needed to explore the mechanism of BC to induce flood tolerance.

Application of iron oxide nanoparticles improves growth and phytochemical constituents of in vitro cultured Carum copticum L.

Iron oxide nanoparticles (FeONPs) are widely used in various applications, such as biomedicine, environmental remediation, and agriculture. Moreover, FeONPs can affect the production of secondary metabolites in plants, which are compounds that have various biological and pharmacological activities. Therefore, in this study, the ajwain (Carum copticum L.) seeds were grown in MS medium containing different levels of FeONPs (0, 100, 200, and 400 mg l−1). After four weeks, the effects of FeONPs on growth, photosynthesis pigments, total phenolic, and anthocyanin content, activities of some antioxidant enzyme and secondary metabolites of ajwain) were investigated. The results showed that low levels of FeONPs (especially 200 mg l−1) increased fresh weight (231 %), total chlorophyll (49 %), total phenolics (259 %), anthocyanin content (110 %), as well as thymol (8 %) and γ-terpinene (16 %) content. Conversely, 400 mg l−1 FeONPs reduced root length (60 %) and fresh weight (64 %) was associated with a reduction in CAT activity, phenol (55 %), thymol (22 %), and γ-terpinene (18 %) content compared to ajwain treated with 200 mg l−1 FeONPs. This reduction was probably due to the increase in ROS caused by the low catalase enzyme activity and important essential oils compounds such as thymol and γ-terpinene. Thus, our results indicate that FeONPs at certain levels can be used as a new way for in vitro production of valuable essential oils and antioxidant compounds in ajwain.

Analysis of the Mechanism of Wood Vinegar and Butyrolactone Promoting Rapeseed Growth and Improving Low-Temperature Stress Resistance Based on Transcriptome and Metabolomics.

Rapeseed is an important oil crop in the world. Wood vinegar could increase the yield and abiotic resistance of rapeseed. However, little is known about the underlying mechanisms of wood vinegar or its valid chemical components on rapeseed. In the present study, wood vinegar and butyrolactone (γ-Butyrolactone, one of the main components of wood vinegar) were applied to rapeseed at the seedling stage, and the molecular mechanisms of wood vinegar that affect rapeseed were studied by combining transcriptome and metabolomic analyses. The results show that applying wood vinegar and butyrolactone increases the biomass of rapeseed by increasing the leaf area and the number of pods per plant, and enhances the tolerance of rapeseed under low temperature by reducing membrane lipid oxidation and improving the content of chlorophyll, proline, soluble sugar, and antioxidant enzymes. Compared to the control, 681 and 700 differentially expressed genes were in the transcriptional group treated with wood vinegar and butyrolactone, respectively, and 76 and 90 differentially expressed metabolites were in the metabolic group. The combination of transcriptome and metabolomic analyses revealed the key gene-metabolic networks related to various pathways. Our research shows that after wood vinegar and butyrolactone treatment, the amino acid biosynthesis pathway of rapeseed may be involved in mediating the increase in rapeseed biomass, the proline metabolism pathway of wood vinegar treatment may be involved in mediating rapeseed's resistance to low-temperature stress, and the sphingolipid metabolism pathway of butyrolactone treatment may be involved in mediating rapeseed's resistance to low-temperature stress. It is suggested that the use of wood vinegar or butyrolactone are new approaches to increasing rapeseed yield and low-temperature resistance.

Volatility Transmission between Oil Price and Exchange Rate

This article presents a study on the transmission of oil price volatility to the exchange rates of 14 countries (net oil exporters and importers) during the period from 02/01/2000 to 31/11/2022. The aim is to compare the effect of oil price fluctuations on exchange rate volatility based on the country's nature. Using ARCH, GARCH, and GARCH-BEKK models, our results reveal that the real effective exchange rate is significantly linked to fluctuations in the real oil price for both categories of countries: oil importers and exporters. These findings have important implications for monetary, fiscal, inflationary, and trade policies for these countries.

Chemical characterization and biological potentials of the essential oil from the peel of the fruit of Citrus x sp

Considering the importance of essential oils, the study aimed to chemically characterize the peel essential oil of Citrus x sp, determine the phenolic compounds, verify the toxicity against Artemia salina, and test the anti-inflammatory, larvicides, and activities with molluscicides. The peel essential oil of Citrus x sp was extracted by the hydrodistillation technique. GC/MS shows that the major component of the essential oil is limonene (70.25%), observing similarity between the peel essential oil of the same species and between species of the same genus. The total phenolic was 19,25 EAT g-1. The essential oil showed anti-inflammatory, larvicide, and molluscicide potential, with EC50 = 400.05 mg L-1, LC50 = 20.26 μg mL-1 and LC90 = 87,50 μg mL-1, respectively. It did not show toxicity against Artemia salina. The results indicate that the chemical compounds of the peel essential oil of Citrus x sp, which are mostly monoterpenes, prove their wide biological activity, and their use is encouraged.

Isolation of Rhizobium from Moisture Stress Imposed Groundnut Nodules

Groundnut is an important oil seed crop accounts for a less than half of the major oilseeds produced in the country. Oil content of Groundnut varies from 44 % to 50 % depending upon the varieties and agronomic practices. It is also called as ‘king of oil seeds’ More than 85 % of the crop Is grown under rainfed conditions in low fertile soils. Rhizobium is a well-known symbiotic nitrogen fixing bacteria. Inoculation of Rhizobium improves plant growth, pod kernel and Oil yield. Rhizobium species help in improving root nodulation and nitrogen fixation, enhancing plant growth and yield of leguminous plants including groundnut under moisture stress conditions. Hence the present study is to isolate Rhizobium species from groundnut nodules by following method given by Vincent (1970) after growing them on Yeast Mannitol Agar Media morphological characteristics were studied, which can be further used for improving nodulation efficiency and plant growth promotion under moisture stress conditions.

Soil Organic Matter and Bulk Density: Driving Factors in the Vegetation-Mediated Restoration of Coastal Saline Lands in North China

Coastal saline soils are an important soil resource that, when restored, can enhance arable land and preserve the natural ecology. With the aim of improving the use of coastal saline soils, we conducted a spot survey at Bohai coastal saline land to investigate the differences in soil properties between different vegetation types. The soil physical and chemical properties of various vegetation types, including Aeluropus sinensis, Imperata cylindrica, Tamarix chinensis, Lycium chinense, Hibiscus moscheutos, Helianthus annuus, Gossypium hirsutum, and Zea mays, were examined at two depth layers: 0–20 cm and 20–40 cm, and in two seasons, spring and autumn. The soil properties were compared with bare land as a control. The results indicated that the electrical conductivity, total soil salt content, sodium adsorption ratio, and bulk density of soils with vegetation cover were lower than those with bare land. On the other hand, soil pH, organic matter content, mean weight diameter, and saturated hydraulic conductivity were higher. The redundancy analysis results revealed a substantial positive correlation between soil pH, saturated hydraulic conductivity, water content, mean weight diameter, and organic matter content, as well as a significant positive correlation between soil electrical conductivity, total soil salt content, sodium adsorption ratio, and bulk density. Soil pH, saturated hydraulic conductivity, water content, mean weight diameter, organic matter content, and soil electrical conductivity, total soil salt content, sodium adsorption ratio, and bulk density were negatively correlated. The results of the structural equation model and variance decomposition showed that soil organic matter and bulk density were the key factors affecting the degree of soil salinization, and compared with their independent effects, their combined effect on soil salinization was greater. This study’s conclusions can provide a point of reference for further research on the mechanisms of soil improvement and desalinization in coastal saline land.