Natural Soil Research Articles

Drought response revealed by chromatin organization variation and transcriptional regulation in cotton.

Cotton is a major world cash crop and an important source of natural fiber, oil, and protein. Drought stress is becoming a restrictive factor affecting cotton production. To facilitate the development of drought-tolerant cotton varieties, it is necessary to study the molecular mechanism of drought stress response by exploring key drought-resistant genes and related regulatory factors. In this study, two cotton varieties, ZY007 (drought-sensitive) and ZY168 (drought-tolerant), showing obvious phenotypic differences under drought stress, were selected. A total of 25,898 drought-induced genes were identified, exhibiting significant enrichment in pathways related to plant stress responses. Under drought induction, At subgenome expression bias was observed at the whole-genome level, which may be due to stronger inhibition of Dt subgenome expression. A gene co-expression module that was significantly associated with drought resistance was identified. About 90% of topologically associating domain (TAD) boundaries were stable, and 6613 TAD variation events were identified between the two varieties under drought. We identified 92 genes in ZY007 and 98 in ZY168 related to chromatin 3D structural variation and induced by drought stress. These genes are closely linked to the cotton response to drought stress through canonical hormone-responsive pathways, modulation of kinase and phosphatase activities, facilitation of calcium ion transport, and other related molecular mechanisms. These results lay a foundation for elucidating the molecular mechanism of the cotton drought response and provide important regulatory locus and gene resources for the future molecular breeding of drought-resistant cotton varieties.

Short-term effects of irrigation and nitrogen management on paddy soil carbon pools under deep placement of basal fertilizer nitrogen.

Active soil organic carbon (SOC) fractions are major driving factors of soil fertility. Understanding the effects of water and fertilizer management on changes in active SOC fractions helps improve soil quality and maintain high agricultural productivity. We conducted a 3-year field experiment in Northeast China. In this experiment, natural soil (CKT) was used as a blank, and two irrigation regimes were established: conventional flooded irrigation (FI) and controlled irrigation (CI). Four nitrogen application levels were set for both irrigation regimes under deep placement of basal fertilizer N: Nd0 (0 kg ha-1), Nd (110 kg ha-1), Nd1 (99 kg ha-1), and Nd2 (88 kg ha-1). After 3 years, at similar N fertilizer application rate, the rice yield, total organic carbon (TOC), and active SOC fraction content of CI were higher under CI than FI. The growth rate of rice yield was 3.8% -8.63% under CI than FI. Under CI, the rice yield, active SOC fractions contents and carbon pool management index (CPMI) did not decrease with decreasing N application rate but instead reached the highest level in the CNd1 treatment. Overall, CI with Nd1 treatment appears to be the best practice for improving soil fertility and crop productivity in Northeast China.

Moving towards a mechanistic understanding of biostimulant impacts on soil properties and processes: a semi-systematic review

Biostimulants are gaining prominence in scientific research, with the potential to enhance plant productivity through benefits to crop yield/quality and tolerance to environmental stresses. Through possible improvements to nutrient use efficiency, they may also lessen the adverse environmental impacts of conventional inorganic fertilizer use in agriculture. The application of biostimulants is currently uncommon as a farming practice, with uncertain effectiveness in delivering these potential benefits. Current research focuses on biostimulant effects on plant physiological changes. There is little scientific evidence on the impact of biostimulants on soil properties (biological, physical, or chemical) or soil functions. This knowledge gap should be addressed considering the vital role of soil processes in the bioavailability of nutrients, as reflected in crop productivity. This review evaluates laboratory and field experimental work on the effectiveness of common, non-microbial biostimulants, with a focus on their modes of action within the soil matrix. Of 2,097 initial articles returned through the search strings, 10 were within the scope of this review. A common soil biostimulant mechanism emerges from this literature. This relates to the supply of nutrients provided by the biostimulants, which stimulate native soil microbiology in mineralizing organic material in the soil, thus producing more bioavailable nutrients for plant uptake. Additionally, some articles link biostimulant effects to soil physical and chemical changes, which in turn impact soil biology (and vice versa). However, there is inconsistent evidence to provide full support for these explanatory mechanisms. This review highlights the need for further research into the effect of biostimulants on the native soil microbiology and associated soil properties, to provide greater clarity on biostimulants’ modes of action and greater mechanistic insights into how they can be used to improve crop production.

Transformation and Degradation of PAH Mixture in Contaminated Sites: Clarifying Their Interactions with Native Soil Organisms

Soil contamination of polycyclic aromatic hydrocarbons (PAHs), especially caused by the mixture of two or more PAHs, raised great environmental concerns. However, research on the migration and transformation processes of PAHs in soils and their interactions with native communities is limited. In this work, soil samples from uncontaminated sites around the industrial parks in Handan, Hengshui, and Shanghai were artificially supplemented with three concentrations of anthracene (Ant), 9-chloroanthracene (9-ClAnt), benzopyrene (BaP), and chrysene (Chr). Ryegrass was planted to investigate the degradation of PAHs and its interaction with native soil organisms in the constructed ryegrass–microbe–soil microcosmic system. The bacterial and fungal communities in soil were affected by PAHs; their species diversity and relative abundance changed after exposure to different concentrations of PAHs, among which Lysobacter, Bacillus, Pseudomonas, and Massilia bacteria were correlated to the degradation of PAHs. On the 56th day, the contents of BaP, Chr, and Ant decreased with the degradation process, while the degradation of 9-ClAnt was limited. Nineteen intermediates, including hydroxylation and carboxylated compounds, were identified. The present research would help clarify the potential interactions between PAHs and native organisms in contaminated sites, providing fundamental information for evaluating the transformation risks of PAHs in the natural environment.

Linking phosphorus fertility to soil microbial diversity and network complexity in citrus orchards: Implications for sustainable agriculture

Continuous input of chemical fertilizers causes soil acidification, land degradation, and water eutrophication, but its impact on soil microbial communities and co-occurrence patterns of microboes is unclear. In this study, we evaluated the impact of chemical fertilizer on bacterial community diversity and ecological network at 75 citrus sites in a watershed where chemical fertilizer is continuously applied. In addition, 25 natural forest sites adjacent to citrus sites were used as references to compare the potential effects of land conversion from natural forests to citrus orchards on soil bacterial diversity and microbial network. The results showed that the cultivation of citrus results in soil phosphorus (P) accumulation, with significantly higher available and mineral-bound phosphate contents than those found in soils of natural forests. Citrus soil average soil available P was 73.2 mg/kg, which was 20 times higher than that in forest soils. As the P content accumulates, soil bacterial Shannon index linearly decreases from 7.06 to 5.93 and is significantly lower than that of adjacent natural forest soils (7.13). Low P fertility soils have higher microbial network complexity and stability, containing more microbial communities and tighter relationships between microbes compared to higher P fertility soils. Soil P content and soil pH regulates soil microbial network complexity and stability. In addition, soil bacterial community structure in soils of natural forests is significantly different from that in citrus soils, and the bacterial community structure in high P soils is different from that in medium and low P soils. Soil P fertility reduces the relative abundance of dominant communities including Proteobacteria, Bacteroidetes, and Gemmatimonadetes, and also changes the relative abundance of some functional microbial communities, such as some phosphorus cycling microorganisms, including Acetobacteraceae and Beijerinckiaceae. In conclusion, soil phosphate accumulation severely alters soil bacterial community diversity, complexity, stability, and functionality. This could have negative impacts on soil functional stability and the sustainability of citrus orchards.

Preparation and Biological Activity Studies of Octenyl Succinic Anhydride Starch-Based Emulsions Containing Natural Essential Oils and Their Components

In this study, clove essential oil (CL), eugenol (EU), and cinnamaldehyde (CI) were immobilized in starch sodium octenyl succinate (SSO) using an emulsification method. The main characteristics, stability, and biological properties of the prepared emulsions were established. Particle size analyses using dynamic light scattering showed that the smaller droplets were characteristic of emulsions containing CI (205–218 nm) and EU (181–236 nm), while the largest droplets were determined for CL emulsions (293–348 nm). Moreover, the highest antioxidant activity was determined for CL (79–83%) and EU (80–88%) emulsions, while CI emulsions showed the greatest antibacterial activity. The obtained emulsions were applied to the paper sheets and the bioactive properties of coated paper were studied. Evaluation of antioxidant properties revealed that high antioxidant activity reaching 76–92% and 87–91% was characteristic of coatings containing CL and EU, respectively. Meanwhile, coatings containing CI showed quite low antioxidant activity (4–9%) but demonstrated the greatest antimicrobial effect on Gram-negative and Gram-positive bacteria as well as yeasts. Hence, CL and EU emulsions could be used as effective natural antioxidants, whereas CI emulsions could be applied as an antimicrobial agent on cellulose-based substrates for a wide range of human health protection applications.

Molecular Composition of Humic Acids of Different Aged Fallow Lands and Soils of Different Types of Use in Northwest of Russia

Post-agrogenic transformation of fallow soils leads to changes in soil carbon content, the molecular composition of humic substances, and rates of organic matter stabilization, which can affect climate change on the planet. In this regard, we analyzed the molecular composition of humic acids isolated from natural and fallow soils in the southern Taiga zone of northwest Russia. Different-aged soils on fallow lands represent a model of soil transformation in time, and data on the transformation of soil humic acid molecular composition make a significant contribution to the understanding of soil organic matter stabilization aspect issues. In this case, the molecular structure of humic acids isolated from natural and fallow soils in northwest Russia was analyzed. To study the molecular composition of HAs, the elemental composition was analyzed, and 13C (CP/MAS) NMR spectroscopy of HAs isolated from different aged abandoned soils and soils of different types of use was carried out. The obtained data showed that with the increasing age of soils in the fallow state, there is an increase in the carbon content of humic acids as well as a decrease in nitrogen content. As a result of the increasing age of soils in the fallow state, there are dynamics in the content of aromatic structural fragments in humic acids: 34% for 40 years old, 28% for 80 years old, and 31% for 120 years old. This is due to changes in the precursors of humification and the further transformation of plant residues in the soil. Re-involved fallow land soils lead to an increase in the content of aromatic structural fragments in the composition of HA in relation to HA extracted from mature soils. The lowest content of aromatic structural fragments was observed in the humic acids of 130-year-old agricultural soil, which is associated with the long-term application of organic fertilizers.

Wastewater purification and recycling using plants in an arid environment for agricultural purposes: case of the Algerian Sahara

The aim of this study is to apply a water treatment technique (phyto-purification) in the Algerian Sahara, an arid region, to resolve the scarcity of irrigation, recycled wastewater and preserve Saharian ecosystems composed of sand and two species of aquatic plants: Typha latifolia and Imperata cylindrica. The choice of these plants was determined based on the natural vegetation, soil and climatic characteristics of the study area. To this end, we developed an experimental pilot composed of three tanks measuring 30 cm × 35 cm × 45 cm, arranged with a filter bed of sand and gravel. Two of these tanks are sown with the above-mentioned plants, while the third tank, serving as a control, is not. The values of the main wastewater pollution parameters, namely total nitrogen compounds, ammonium (NH4+), chemical oxygen demand (COD) and suspended solids measured at the outlet of the device, substantiate the performance of this treatment system. Indeed, the nitrogen reduction rate increased from 63% in the unplanted control filters to around 80% in the planted filters, and from 81 to 88% for NO3−. Regarding chemical oxygen demand (COD), the reduction rate exceeds 88.37% for the three tanks. The study of the analytical approach to modeling the purification kinetics reveals that the kinetics of COD and NH4+ are well correlated with the first-order model, with an explained variance varying between 68.1 and 81.6% for COD and 83.5 and 92.3% for ammonium. The Riverside diagram highlights that all treated water samples fall into the low sodium risk and high salinity risk class. Build on the Na% values; all purified waters have characteristics suitable for water use for irrigation.

Intensive Citrus Cultivation Suppresses Soil Phosphorus Cycling Microbial Activity

Soil microbes are key drivers in regulating the phosphorus cycle. Elucidating the microbial mineralization process of soil phosphorus-solubilizing bacteria is of great significance for improving nutrient uptake and yield of crops. This study investigated the mechanism by which citrus cultivation affects the soil microbial acquisition strategy for phosphorus by measuring the abundance of the phoD gene, microbial community diversity and structure, and soil phosphorus fractions in the soils of citrus orchards and adjacent natural forests. The results showed that citrus cultivation could lead to a decrease in soil pH and an accumulation of available phosphorus in the soil, with a content as high as 112 mg·kg-1, which was significantly higher than that of natural forests (3.7 mg·kg-1). Citrus cultivation also affected the soil phosphorus fractions, with citrus soil having higher levels of soluble phosphorus (CaCl2-P), citrate-extractable phosphorus (Citrate-P), and mineral-bound phosphorus (HCl-P). The phosphorus fractions of natural forest soils were significantly lower than those of citrus soils, whereas the phoD gene abundance and alkaline phosphatase activity were significantly higher in natural forest soils than in citrus soils. High-throughput sequencing results showed that the Shannon diversity index of phosphate-solubilizing bacteria in citrus soils was 4.61, which was significantly lower than that of natural forests (5.35). The microbial community structure in natural forests was also different from that of citrus soils. In addition, the microbial community composition of phosphate-solubilizing bacteria in citrus soils was also different from that of natural forests, with the relative abundance of Proteobacteria being lower in natural forest soils than in citrus soils. Therefore, citrus cultivation led to a shift of soil microbial acquisition strategy for phosphorus, with external phosphorus addition being the main strategy in citrus soils, whereas microbial mineralization of organic phosphorus was the main strategy in natural forest soils to meet their growth requirements.

Tracing the contribution and fate of synthetic nitrogen fertilizer in young apple orchard agrosystems

Excessive synthetic nitrogen (N) inputs in intensive orchard agrosystems of developing countries are a growing concern regarding their adverse impacts on fruit production and the environment. Quantifying the distribution and contribution of fertilizer N is essential for increasing N use efficiency and minimizing N loss in orchards. A 15N tracer experiment was performed in a young dwarf apple orchard over two growing seasons to determine the fertilizer N transformation and fate. Fertilizer N primarily contributed to 25 % to 75 % of soil nitrate in the top 60 cm, but the contribution to soil microbial biomass N and fixed ammonium was <8 %, with the contribution to plant N ranging from 9 % to 19 %. In most growth periods, soil nitrate and fixed ammonium contents derived from native soil with N fertilization were higher than those not receiving N fertilizer. The N use efficiency of plants was only 2.6 % and 4.9 % in the first and second seasons, respectively, in contrast to 56.6 % and 54.0 % of N recovered in soil. Meanwhile, N assimilated into microbial biomass accounted for 0.8 %, and the proportion fixed by clay minerals was 3.5 %–5.2 %. One season after N fertilization, the nitrate below the 1 m soil layers accounted for 4.6 % of the applied N fertilizer, and the proportion increased to 22.5 % after two seasons. The N loss rate via N2O emission was 0.4 % over two years. The application of N fertilizer facilitated indigenous soil N mineralization, and abiotic ammonium fixation more efficiently retained synthetic N than microbial immobilization. These findings provide new insight into orchard N cycling, and attention should be given to the improvement of soil N retention and turnover capacity regulated by soil microbial and abiotic processes, as well as the potential environmental impacts of additional soil N mineralization resulting from prolonged chemical N fertilization.

Hg Content Characteristics and Safe Planting Zoning of Paddy Soil and Rice in Guizhou Province

Guizhou Province ranks first in terms of Hg reserves and production in the country, and rice is its largest grain crop. In order to study the characteristics and pollution causes of soil-rice Hg content at the provincial level in Guizhou and to carry out safe planting zoning, 1 564 pairs of soil-rice samples, 470 natural soil samples, and 203 individual paddy soil samples were collected to test their Hg content and basic physical and chemical properties of the soil. The results showed that:① Paddy soil was mainly neutral and acidic, the paddy soil ω (Hg) range was 0.005-93.06 mg·kg-1, and the geometric mean was 0.864 mg·kg-1. The Hg content of paddy soil in Guizhou Province was significantly higher than that in natural soil (0.16 mg·kg-1,P &lt; 0.05). Compared with the filtered value and control value, the soil samples exceeded the standard by 63.25% and 14.71%, respectively. Among them, the soil Hg pollution in Danzhai County of Qiandongnan Prefecture, Wuchuan County of Zunyi City, Zhenfeng County of Qianxinan Prefecture, and Wanshan District of Tongren City was more prominent. ② Rice ω(Hg) ranged from 0.000 5 to 0.52 mg·kg-1, and the geometric mean was 0.010 mg·kg-1, the percentage of rice Hg content exceeding the standard was 25.87%, and the exceeding points were mainly distributed in Suiyang County of Zunyi City, Zhenfeng County of Qianxinan Prefecture, Xixiu District of Anshun City, Bijiang District of Tongren City, and other industrial and mining activity-intensive areas. ③ The majority of the study area was in the priority protection category (74.75%); the safe use category accounted for (24.62%); and the strictly controlled category (0.93%) was scattered in Danzhai County at the border between Qiannan Prefecture and Qiandongnan Prefecture, Zhenfeng County in Qianxinan Prefecture, and Wanshan District in Tongren. It is not recommended to plant rice, which can be used as feed for reproduction.

Employing Plant Parasitic Nematodes as an Indicator for Assessing Advancements in Landfill Remediation

This research concentrated on the soil nematode communities inhabiting a reclaimed municipal waste landfill situated in Giedlarowa, southeastern Poland. The landfill, which was layered with natural soil in 2008 and cultivated with grass, served as the primary focus of the study. Samples for analysis were taken four times (October 2020 (Pf1), March 2021 (Pf2), October 2021 (Pf3), and March 2022 (Pf4)), with each time comprising three repetitions. The analysis was conducted employing microscopic examination, which enabled the identification of up to five trophic groups and species of plant-parasitic nematodes. During the assessment of nematode activity in the initial and subsequent growing seasons, it was found that Pratylenchus crenatus emerged as the predominant species among herbivorous nematodes in the plant-parasitic nematode (PPNs) community. Criconemoides informis, another nematode species, held a significant rank as well; their population during the third growing season formed the most substantial group among the PPN organisms dwelling in the soil. Nevertheless, interesting results were also obtained by populations of nematodes of the genus Hemicyclophora and Loofia, which were characterized by high densities. The analyzed soil environment showcased a C:N ratio spanning from 0.69 to 3.13. Furthermore, the soil samples exhibited variations in phosphorus content (P2O5), ranging from 4.02 mg/100 g to 10.09 mg/100 g. Criconemoides informis, Longidorus attenuates, Mesocriconema spp., and Bitylenchus maximus exhibited a positive correlation with soil mineral levels of calcium (Ca) and magnesium (Mg).

Role of Economic Expansion, Energy Utilization and Urbanization on Climate Change in Egypt based on Artificial Intelligence

This study employs machine-learning algorithms (ML), specifically Random Forest (RF) and Gradient Boosting (GB), to assess the impact of various factors, including Gross Domestic Product (GDP) growth, urbanization, and energy consumption, on carbon dioxide emissions (CO2). The research underscores the RF algorithm's superior accuracy in determining independent variables' influence on CO2 emissions compared to GB. Furthermore, the study reveals that natural gas is the most significant contributor to CO2 emissions in Egypt, accounting for 49.7% of the total, followed closely by oil at 46.7%. The effect of other variables on CO2 emissions is relatively minimal. The findings also establish a strong positive correlation between the consumption of natural gas, oil, and coal and CO2 emissions in Egypt. Additionally, a negative relationship is observed between GDP growth, suggesting a positive trend in environmentally friendly economic expansion and urbanization on CO2 emissions in Egypt. This unique scenario, where urban expansion appears to have an inverse relationship with CO2 emissions, sets Egypt apart from many other countries and signifies a favorable environmental outcome.

Fertilizer Addition Modifies Utilization of Different P Sources in Upland Rice on Strongly P-fixing Andosols

Abstract Aims High Phosphorus (P) efficiencies such as internal P utilization efficiency (PUE) and P acquisition efficiency (PAE) are crucial for upland rice production, particularly on highly P-fixing soils like Andosols. While the effect of root traits associated with high PAE in upland rice has been studied intensively, less attention has been given to the origin of P (native soil-P versus fertilizer-P) taken up by plants when evaluating differences in P efficiency. Here we aim to evaluate the efficiency of different upland rice genotypes to acquire native soil-P and fertilizer-P. Methods Four upland rice genotypes with varying PAE were grown in an Andosol at low- and high-P fertilization level and harvested 9 and 34 days after emergence. Fertilizer-P was labeled with 33P to distinguish between the efficiency to acquire P originating from native soil and fertilizer by measuring plant P uptake. Results Increased fertilizer supply enhanced native soil-P uptake. Under low-P conditions the genotype DJ123 showed a superior PAE and an increased acquisition of native soil-P while AB199 was identified to have a superior internal PUE under P deficient conditions. Differences between genotypes in overall PAE under high-P conditions were not significant but the distinction of P sources showed that genotype DJ123 acquired significantly more native soil-P per unit root than all other genotypes. Conclusions Our results indicate that variations in PAE among genotypes are associated with their ability to access native soil-P. DJ123 emerged as the most adept genotype in acquiring sparingly soluble native soil-P and future studies should unravel the rhizosphere processes underlying increased PAE of native soil-P.

Significant Effect Of Amended Soil On Microbial Flora Of Soil And Plant Growth In Comparison With Natural Low Nutritive Soil

Soil chemical properties, such as Carbon and Nitrogen levels, are crucial for fulfilling the basic needs of plants. The presence of secondary and tertiary nutrients plays a vital role in constructing soil structure, influencing the survival of normal microbial flora, seeds, and later plant growth. The use of chemical fertilizers addresses nutritional deficiencies, but reports indicate that only 40% is utilized by plants, leading to soil issues like salinity and drought logging. When soil lacks essential nutrients, external amendments are necessary, impacting plant growth and crop yield by enhancing normal microbial flora i.e. Plant growth-promoting rhizobacteria (PGPRs). Recognizing the significance of both chemical nutrients and physical properties for healthy plant growth, a soil amendment called "Fertisol soil" was developed. This involved adding basic and secondary nutrients to the soil. The amended soil underwent analytical characterization and was compared with natural soil through chemical analysis and microbial growth assessments. Comparative studies using the amended soil showed improved plant growth and flowering capacity compared to control plants in terms of height and flowering. This highlights the positive impact of balanced nutrient amendments on soil health and overall plant performance.

Natural soil as the peroxymonosulfate activator for efficient remediation and detoxification of bisphenol A: Nonradical-dominated mechanism and the change of soil properties

Peroxymonosulfate (PMS) has been extensively applied in soil refractory organics remediation, but studies without an activator were scarce. Besides, the role of soil as well as the interaction between the soil constituents and PMS remained unclear. Using bisphenol A (BPA) as a model contaminant, our findings demonstrated that soil could efficiently activate PMS for BPA abatement in water and slurry. Free Fe oxides, especially crystalline Fe oxides in soil, were primarily responsible for PMS activation through nonradical pathways (singlet oxygen) for BPA removal, but soil organic matter (SOM) might inhibit the process. Moreover, BPA elimination was almost not inhibited by the addition of anions (Cl−, NO3−, HCO3−, and SO42−) and humic acid, but could be promoted by cations (Fe3+ and Mn2+). PMS oxidation caused an insignificant impact on the bioavailability of heavy metals, except for Fe, Mn, SOM, pH, total phosphorus (TP) content, soil composition, and crystal structure have not changed obviously after PMS treatment. BPA decomposition pathways were proposed based on the intermediates identified. Furthermore, the phytotoxicity of BPA − polluted soil was significantly reduced after PMS remediation in terms of crop growth indexes. Overall, the study provided new insights into the crucial role of soil constituents in PMS activation and inspired more energy or catalyst − saving soil remediation strategies.

Bioprotective effects of different Plant Extracts and Essential Oils against Rhizopus stolonifer and Aspergillus niger causing Post Harvest decay in Grapes

The grapes (Vitis vinifera) are one of the largely consumed fruits in the world. Grape production in Pakistan has increased in the recent years. These are mainly consumed fresh or as dried raisins. Grapes are highly perishable, which makes them liable to rot during transport, storage, and marketing. The perishable nature of grapes leads to a considerable amount of post-harvest loss. The production and quality of grapes are adversely affected by several abiotic and biotic factors. Two different cities Pishin (Balochistan) and Faisalabad (Punjab) fruit market and stores were selected to collect rotten grapes. The fungal pathogens isolated were identified as A. niger and R. stolonifers. The pathogenicity of isolated pathogens was assessed at different temperatures (5, 20, and 30 °C) on the Thompson seedless grape variety. Infection and proliferation of fungi were found conducive at 30°C. As antifungal agents, three organic origin oils, neem, cinnamon, and clove oils with levels i.e., 500, 1000, 2000 ppm as well as marigold and neem extracts with diverse concentrations of like 12.5, 25, and 50% were employed. Among these organic compounds, cinnamon and clove oils at 2000 ppm exhibited 6.54% and 15.3% decay against A. niger, respectively. Meanwhile, against R. stolonifer, cinnamon and clove oils at 2000 ppm exhibited 12.22% and 6.74% decay, respectively. This study's findings focus on the effectiveness of both essential oils and plant extract in significantly delaying the decay process caused by fungal pathogens. The present study underscores the protective ability of the plant extracts and natural oils which could be a way forward for eco-safe management of post-harvest diseases of grapes before they reach the market.

Response of Soil Moisture to Four Rainfall Regimes and Tillage Measures under Natural Rainfall in Red Soil Region, Southern China

Investigating the effects of natural rainfall on the soil moisture for sloping farmland is extremely important for comprehending a variety of hydrological processes. Rainfall regimes can elicit different responses to soil moisture at the depth of soil layers, and the responses may differ depending on the landscape position of the sloping farmland. This paper utilized the surface runoff natural rainfall and soil moisture measured on sloping farmland with conventional tillage and contour tillage in the red soil area of China to investigate the influence of natural rainfall events on soil moisture content and to evaluate if the response results were consistent across the four rainfall regimes. Natural rainfall events were classified into different four regimes in line with rainfall duration, rainfall amount, and the maximum 30 min rainfall intensity (I30) by the k-means clustering method, including advanced, intermediate, uniform and delayed regimes. The result showed that the advanced regime was the predominant one in the study area, which represented 45.9% of the total rainfall events. The rainfall regimes influenced the surface runoff coefficient and runoff depth on sloping farmland for conventional and contour tillage, with the uniform regime generating the highest runoff coefficient (5.20% and 5.82%) and runoff depth (2.00% and 2.05%), respectively. For the conventional tillage, soil moisture at a depth of 0–20 cm increased appreciably when the rainfall amount was larger than 20 mm and larger than 30 mm for the advanced regime. For the contour tillage, soil moisture in 20–40 cm layer increased for the advanced regime when the rainfall amount was larger than 15 mm and 30 mm, while the values were modified with rainfall duration and the antecedent dry day (ADD). A longer rainfall duration had a more obvious effect on soil moisture increasing in deep soil. At a depth of 20 cm, the ADD showed an appreciably positive correlation with the increment in soil moisture, which means that a brief ADD produces a compounding effect for a natural rainfall event. The present results underline the complexity of the effect of the rainfall events on soil moisture under two tillage measures for different rainfall regimes and suggest that the advanced regime significantly affects the distinction of soil moisture and the contour tillage can effectively reduce soil water loss and enhance water storage on the sloping farmland with red soil, presenting a theoretical basis for local soil and water conservation research and sloping farmland conservation tillage management.

Repellent activity of essential oils to the Lone Star tick, Amblyomma americanum

BackgroundThe Lone Star tick, Amblyomma americanum is important to human health because of a variety of pathogenic organisms transmitted to humans during feeding events, which underscores the need to identify novel approaches to prevent tick bites. Thus, the goal of this study was to test natural and synthetic molecules for repellent activity against ticks in spatial, contact and human fingertip bioassays.MethodsThe efficacy of essential oils and naturally derived compounds as repellents to Am. americanum nymphs was compared in three different bioassays: contact, spatial and fingertip repellent bioassays.ResultsConcentration response curves after contact exposure to 1R-trans-chrysanthemic acid (TCA) indicated a 5.6 μg/cm2 concentration required to repel 50% of ticks (RC50), which was five- and sevenfold more active than DEET and nootkatone, respectively. For contact repellency, the rank order of repellency at 50 μg/cm2 for natural oils was clove > geranium > oregano > cedarwood > thyme > amyris > patchouli > citronella > juniper berry > peppermint > cassia. For spatial bioassays, TCA was approximately twofold more active than DEET and nootkatone at 50 μg/cm2 but was not significantly different at 10 μg/cm2. In spatial assays, thyme and cassia were the most active compounds tested with 100% and 80% ticks repelled within 15 min of exposure respectively and was approximately twofold more effective than DEET at the same concentration. To translate these non-host assays to efficacy when used on the human host, we quantified repellency using a finger-climbing assay. TCA, nootkatone and DEET were equally effective in the fingertip assay, and patchouli oil was the only natural oil that significantly repelled ticks.ConclusionsThe differences in repellent potency based on the assay type suggests that the ability to discover active tick repellents suitable for development may be more complicated than with other arthropod species; furthermore, the field delivery mechanism must be considered early in development to ensure translation to field efficacy. TCA, which is naturally derived, is a promising candidate for a tick repellent that has comparable repellency to commercialized tick repellents.Graphical

Microbiota recovery in a chronosquences of impoverished Cerrado soils with biosolids applications

Mining activities put the Brazilian savannas, a global biodiversity hotspot, in danger of species and soil carbon losses. Experiments employing biosolids have been applied to rejuvenate this degraded ecosystem, but a lingering question yet to be answered is whether the microbiota that inhabits these impoverished soils can be recovered towards its initial steady state after vegetation recovery. Here, we selected an 18-year-old restoration chronosequence of biosolids-treated, untreated mining and native soils to investigate the soil microbiota recovery based on composition, phylogeny, and diversity, as well as the potential factors responsible for ecosystem recovery. Our results revealed that the soil microbiota holds a considerable recovery potential in the degraded Cerrado biome. Biosolids application not only improved soil health, but also led to 41.7 % recovery of the whole microbial community, featuring significantly higher microbiota diversity and enriched groups (e.g., Firmicutes) that benefit carbon storage compared to untreated mining and native soils. The recovered community showed significant compositional distinctions from the untreated mining or native soils, rather than phylogenetic differences, with physiochemical properties explaining 55 % of the overall community changes. This study advances our understanding of soil microbiota dynamics in response to disturbance and restoration by shedding light on its recovery associated with biosolid application in a degraded biodiverse ecosystem.