Response of soil heavy metal forms and bioavailability to the application of microplastics across five years in different soil types.

Microplastics (MPs) potentially alter physicochemical and transformation of heavy metals (HMs) in soils, which may depend on the specific characteristics of soil types. However, the dynamical and long-term mechanisms remain to be elucidated. A five-year incubation experiment was conducted to evaluate the influence of MPs on the chemical speciation of Pb, Ni, Cu, Cr, Cd, and As in the meadow, tidal, cinnamon, saline-alkali, and brown soils. From the first year to the fifth year, the clay value of the meadow, tidal, cinnamon, and saline-alkali soils was increased by 31.35 %, 9.63 %, 30.12 %, and 33.12 %, respectively; the pH values of the cinnamon and saline-alkali soils were increased by 15.02 % and 15.86 %, respectively. Besides, speciation distribution results suggested that the application of MPs reduced the liable available (LB) form (F2-dissolved and F3-ion exchangeable) of HMs and increased the potentially available (PB) form (F5-minerals and F6-organic-bound fraction) of HMs in all soils. Compared with other forms, F2 HMs fraction was the most responsive to MPs. Furthermore, the average bioconcentration factor (BCF) of Cr and Pb decreased by 73.75 % and 70.41 % in soils, respectively. Interestingly, soil type showed more impact on the form of HMs, which was associated with the different physicochemical parameters of soils, while application time displayed more impact on the bioavailability of HMs. Moreover, our results suggested that soils with higher clay content and pH values (such as cinnamon and saline-alkali soils) may mitigate the bioavailability of HMs more effectively in the presence of MPs, while soils with lower clay content may be more vulnerable to HMs contamination over time. This work highlights the importance of long-term monitoring of the impact of MPs on HMs dynamics for effective mitigation of soil contamination risks. Our study provides valuable guidance for soil remediation strategies and environmental quality management across different soil types.

Biofilm enhanced the mitigations of antibiotics and resistome in sulfadiazine and trimethoprim co-contaminated soils.

Reducing antibiotic levels in soil ecosystems is vital to curb the dissemination of antimicrobial resistance genes (ARGs) and mitigate global health threats. However, gaps persist in understanding how antibiotic resistome can be suppressed during antibiotic degradation. Herein, we investigate the efficacy of a biochar biofilm incorporating antibiotics-degrading bacterial strain (Arthrobacter sp. D2) to mitigate antibiotic resistome in non-manured and manure-amended soils with sulfadiazine (SDZ) and trimethoprim (TMP) contamination. Results show that biofilm enhanced SDZ degradation by 83.0% within three days and increased TMP attenuation by 55.4% over 60 days in non-manured soils. In the non-manured black soil, the relative abundance of ARGs increased initially after biofilm inoculation. However, by day 30, it decreased by 20.5% compared to the controls. Moreover, after 7 days, biofilm reduced TMP by 38.5% in manured soils and decreased the total ARG abundance by 19.0%. Thus, while SDZ degradation did not increase sulfonamide resistance genes, TMP dissipation led to a proliferation of insertion sequences and related TMP resistance genes. This study underscores the importance of antibiotic degradation in reducing related ARGs while cautioning against the potential proliferation and various ARGs transfer by resistant microorganisms.

Promoting the elemental profile of sorghum grain: Driving factors affecting nutritional properties under nitrogen fertilizer conditions.

Monitoring nitrogen utilization is crucial in agricultural practices, emphasizing the interrelationship between soil health, nutrient management, and human health. The study was conducted to evaluate the impact of N fertilizer on the nutritional characteristics of diverse S. bicolor varieties, namely Alföldi 1, ES Föehn (Lidea Seeds) with a red pericarp, ES Albanus, Albita, and Farmsugro 180 (all white varieties), the study was conducted in sorghum-producing areas where the crop is non-native. Specifically, the study investigated two soil types: loam clay and sandy soil. Furthermore, the respective varieties were grown under N (27% N CAN) fertilizer conditions, involving 60 kg/ha-1 and 120 kg/ha-1 of the treatment rates applied at each experiment site. We measured the specific element concentration in each sample using the Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) technology. Certainly, the results demonstrated that the different S. bicolor varieties had unique nutritional characteristics attributed to several factors such as soil type, variety, and treatment, which showed a significance value of (P < 0.05). The findings demonstrated that the treatments had distinct impacts as stimulators and inhibitors for certain elements. Specifically, the application of 120 kg/ha-1 negatively affected the levels of particular elements, such as Ca mg/kg-1, in loam clay and sandy soil. The statistical analysis of trace microelement variance did not show a significance value (P > 0.05) when considering the year factor, which supported the data analysis's reliability and accuracy. In summary, to enhance the nutritional value of sorghum grain and supply nutrient-rich food choices for individuals, consider factors such as fertilizer response, nutrient uptake by grain, element mineral accumulation, and advisory variety. Additional research could enhance the nutritional properties of sorghum to provide the required dietary stuff, such as grain processing, which can render sorghum a proper addition to a healthy and balanced human diet.

Maize functional requirements drive the selection of rhizobacteria under long-term fertilization practices.

Rhizosphere microbiomes are pivotal for crop fitness, but the principles underlying microbial assembly during root-soil interactions across soils with different nutrient statuses remain elusive. We examined the microbiomes in the rhizosphere and bulk soils of maize plants grown under six long-term (≥ 29 yr) fertilization experiments in three soil types across middle temperate to subtropical zones. The assembly of rhizosphere microbial communities was primarily driven by deterministic processes. Plant selection interacted with soil types and fertilization regimes to shape the structure and function of rhizosphere microbiomes. Predictive functional profiling showed that, to adapt to nutrient-deficient conditions, maize recruited more rhizobacteria involved in nutrient availability from bulk soil, although these functions were performed by different species. Metagenomic analyses confirmed that the number of significantly enriched Kyoto Encyclopedia of Genes and Genomes Orthology functional categories in the rhizosphere microbial community was significantly higher without fertilization than with fertilization. Notably, some key genes involved in carbon, nitrogen, and phosphorus cycling and purine metabolism were dominantly enriched in the rhizosphere soil without fertilizer input. In conclusion, our results show that maize selects microbes at the root-soil interface based on microbial functional traits beneficial to its own performance, rather than selecting particular species.

Site properties, environmental factors, and crop identify influence soil bacterial communities more than municipal biosolid application.

Reducing the environmental impact of Canadian field crop agriculture, including the reliance on conventional synthesised fertilisers, are key societal targets for establishing long-term sustainable practices. Municipal biosolids (MSB) are an abundant, residual organic material, rich in phosphate, nitrogen and other oligo-nutrients, that could be used in conjunction with conventional fertilisers to decrease their use. Though MBS have previously been shown to be an effective fertiliser substitute for different crops, including corn and soybean, there remain key knowledge gaps concerning the impact of MBS on the resident soil bacterial communities in agro-ecosystems. We hypothesised that the MBS fertiliser amendment would not significantly impact the structure or function of the soil bacterial communities, nor contribute to the spread of human pathogenic bacteria, in corn or soybean agricultural systems. In field experiments, fertiliser regimes for both crops were amended with MBS, and compared to corn and soybean plots with standard fertiliser treatments. We repeated this across four different agricultural sites in Quebec, over 2021 and 2022. We sampled MBS-treated, and untreated soils, and identified the composition of the soil bacterial communities via 16S rRNA metabarcoding. We found no indication that the MBS fertiliser amendment altered the structure of the soil bacterial communities, but rather that the soil type and crop identities were the most significant factors in structuring the bacterial communities. Moreover, there was no evidence that the MBS-treated soils were enriched in potential human bacterial pathogens over the two years of our study. Our analysis indicates that not only can MBS function as substitutes for conventional, synthesised fertilisers, but that they also do not disrupt the structure of the resident soil bacterial communities in the short term. Finally, we suggest that the use of MBS in agro-ecosystems poses no greater concern to the public than existing soil bacterial communities. This highlights the significant role MBS could potentially have in reducing the use of conventional industrial fertilisers and improving agricultural production, without risking environmental contamination.

Di-(2-ethylhexyl) phthalate (DEHP) contamination suppressed soil microbial biomass carbon and mitigated CO2 emissions against the background of alfalfa from different soils.

Plastic mulching and organic amendments are prevalent agricultural practices worldwide. Plastic mulching has long been suspected as a significant source of DEHP contamination in terrestrial ecosystems. However, effects of DEHP contamination on greenhouse gas emissions and microbial biomass carbon (MBC) remain unclear. Here, a microcosm experiment was set up to assess the impact of DEHP exposure on MBC and carbon dioxide (CO2) emission in two different soils (acidic and alkaline) with the inclusion of alfalfa straw. The treatment includes: (i) control with no amendment (T1); (ii) alfalfa straw addition (20 g kg-1) (T2); (iii) DEHP (10 mg kg-1) + alfalfa straw (T3); and (iv) DEHP (100 mg kg-1) + alfalfa straw (T4). Against the background of alfalfa inclusion, DEHP exposure led to a potential reduction in cumulative CO2 emissions by 16.35 % and 6.91 % in alkaline soil and 12.27 % and 13.65 % in acidic soil for T3 and T4, respectively. The addition of DEHP triggered CO2 emissions and manifested a detrimental negative priming effect in both soil types. In both soils, average CO2 emission fluxes were highest for the T2 treatment. The MBC fluctuated at around 80 mg kg-1 for the control group, alfalfa straw alone (T2) treatment considerably enhanced MBC contents, whereas DEHP contamination in T3 and T4 treatments suppressed the stimulatory effect of alfalfa on MBC in both alkaline and acidic soils. Furthermore, a positive relationship was observed between soil CO2 emissions and MBC in both soils. Overall, these findings highlight the toxic impact of DEHP on MBC and its role in mitigating CO2 emissions in diverse soils. DEHP exposure counters the CO2 emissions induced by alfalfa straw. In addition, the inhibitory effect of DEHP on CO2 fluxes in alkaline soil is less pronounced than in acidic soil. Therefore, further cutting-edge research is crucial since DEHP contamination poses serious ecological threats to agroecosystems.

Effects of heavy metal and disinfectant on antibiotic resistance genes and virulence factor genes in the plastisphere from diverse soil ecosystems.

Antibiotic-resistance genes (ARGs) are world-wide contaminants posing potential health risks. Quaternary ammonium compounds (QACs) and heavy metals can apply selective pressure on antibiotic resistance. However, there is a lack of evidence regarding their coupled effect on changes in ARGs and virulence factor genes (VFGs) in various soil types and their plastispheres. Herein, we conducted a microcosm experiment to explore the abundances and profiles of ARGs and VFGs in soil plastispheres from three distinct types of soils amended with Cu and disinfectants. The plastispheres enriched the ARGs' abundance compared to soils and stimulated the coupling effect of combined pollutants on promoting the abundances of ARGs and VFGs. Horizontal gene transfer inevitably accelerates the propagation of ARGs and VFGs in plastispheres under pollutant stress. In plastispheres, combined exposure to disinfectants and Cu increased some potential pathogens' relative abundances. Moreover, the combined effect of disinfectants and Cu on ARGs and VFGs changed with soil type in plastispheres, emphasising the necessity to incorporate soil type considerations into health risk assessments for ARGs and VFGs. Overall, this study highlights the high health risks of ARGs under the selective pressure of combined pollutants in plastispheres and provides valuable insights for future risk assessments related to antibiotic resistance.

Identification of Soil Types and Salinity Using MODIS Terra Data and Machine Learning Techniques in Multiple Regions of Pakistan.

Soil, a significant natural resource, plays a crucial role in supporting various ecosystems and serves as the foundation of Pakistan's economy due to its primary use in agriculture. Hence, timely monitoring of soil type and salinity is essential. However, traditional methods for identifying soil types and detecting salinity are time-consuming, requiring expert intervention and extensive laboratory experiments. The objective of this study is to propose a model that leverages MODIS Terra data to identify soil types and detect soil salinity. To achieve this, 195 soil samples were collected from Lahore, Kot Addu, and Kohat, dating from October 2022 to November 2022. Simultaneously, spectral data of the same regions were obtained to spatially map soil types and salinity of bare land. The spectral reflectance of band values, salinity indices, and vegetation indices were utilized to classify the soil types and predict soil salinity. To perform the classification and regression tasks, the study employed three popular techniques in the research community: Random Forest (RF), Ada Boost (AB), and Gradient Boosting (GB), along with Decision Tree (DT), K-Nearest Neighbor (KNN), and Extra Tree (ET). A 70-30 test train validation split was used for the implementation of these techniques. The efficacy of the multi-class classification models for soil types was evaluated using accuracy, precision, recall, and f1-score. On the other hand, the regression models' performances were evaluated and compared using R-squared (R2), Mean Squared Error (MSE), Mean Absolute Error (MAE), and Root Mean Squared Error (RMSE). The results demonstrated that Random Forest outperformed other methods for both predicting soil types (accuracy = 65.38, precision = 0.60, recall = 0.57, and f1-score = 0.57) and predicting salinity (R2 = 0.90, MAE = 0.56, MSE = 0.98, RMSE = 0.97). Finally, the study designed a web portal to enable real-time prediction of soil types and salinity using these models. This web portal can be utilized by farmers and decision-makers to make informed decisions regarding soil, crop cultivation, and agricultural planning.

Dataset on effects of nitrogen fertilizer and soil moisture levels on the performance of Water Efficient Maize (WEMA) on Ferric Luvisol and Rhodic Ferralsol soils.

The most important factors affecting maize production are water stress and nitrogen deficiency. A greenhouse experiment was conducted to assess the influence of different N fertilizers and soil moisture levels on the growth and yields of the WEMA variety on two different soils. The experiment was designed in a factorial of 5 × 2 × 2 fitted into a three replicate completely randomized design. Treatments included five N fertilizer rates (0, 60, 120, 180, and 240 kg N/ha), two soil moisture levels [45 and 100% field capacity], and two soil types. The morphological traits, physiological traits, drought indices and agronomic efficiency were determined. The data were analyzed using GenStat, version 11, analysis of variance (ANOVA), and differences in treatment means were assessed with a probability of 5% using the Duncan Multiple Range Test (DMRT). The associations between the measured parameters were examined using regression and correlation analysis. Data were analyzed using analysis of variance (ANOVA) of GenStat, edition 11, and differences in treatment means were tested using the Duncan Multiple Range Test (DMRT) with a probability of 5%. The regression and correlation analyses were used to examine the relationships between the measured parameters.

Swine-manure composts induce the enrichment of antibiotic-resistant bacteria but not antibiotic resistance genes in soils.

Composting is a common and effective strategy for reducing antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) from animal manure. However, it is unclear whether the advantages of composting for the control of ARGs and ARB can be further increased in land application. This study investigated the fate of ARB and ARGs after land application of swine-manure composts (SMCs) to three different soil types (red soil, loess and black soil). The results showed that although the SMCs caused an increase in the abundance of total ARGs in the soil in the short period, they significantly reduced (p < 0.01) the abundance of total ARGs after 82 days compared to the control. The decay rate of ARGs reflected by the half-life times (t1/2) varied by soil type, with red soil being the longest. The SMCs mainly introduced ermF, tetG and tetX into the soils, while these ARGs quickly declined to the control level. Notably, SMCs increased the number of ARB in the soils, especially for cefotaxime-resistant bacteria. Although SMCs only affected the microbiome significantly during the early stage (p < 0.05), it took a much longer time for the microbiome to recover compared to the control. Statistical analysis indicated that changes in the microbial community contributed more to the fate of ARGs during SMCs land application than other factors. Overall, it is proposed that the advantages of ARGs control in the composting process for swine manure can be further increased in land application, but it can still bring some risks in regard to ARB.

Revealing the relative importance among plant species, slope positions, and soil types on rhizosphere microbial communities in northern tropical karst and non-karst seasonal rainforests of China.

Rhizosphere microbes have an extremely close relationship with plants and the study on the relationship between rhizosphere microorganisms and their influencing factors is conducive to the protection of vegetation and the maintenance of biodiversity. Here we investigated how plant species, slope positions and soil types affect the rhizosphere microbial community. Slope positions and soil types were collected from northern tropical karst and non-karst seasonal rainforests. The results indicated that soil types played a predominant role in the development of rhizosphere microbial communities (28.3% of separate contribution rate), more than plant species identity (10.9% of separate contribution rate) and slope position (3.5% of separate contribution rate). Notably, environmental factors closely related to soil properties were the major influence factors that controlling the rhizosphere bacterial community structure in the northern tropical seasonal rainforest, especially pH. Additionally, plant species also influenced the rhizosphere bacterial community. In low nitrogen content soil environments, rhizosphere biomarkers of dominant plant species were often nitrogen-fixing strains. It suggested that plants might have a selective adaptation mechanism to rhizosphere microorganisms to obtain the advantages of nutrient supply. Overall, soil types exerted the biggest influence on rhizosphere microbial community structure, followed by plant species and finally slope positions.

Spatial-Temporal Variations in of Soil Conservation Service and Its Influencing Factors under the Background of Ecological Engineering in the Taihang Mountain Area, China.

Soil conservation (SC) plays an important role in maintaining regional land productivity and sustainable development. Ecological engineering (EE) is being implemented in different countries to effectively alleviate the damage to the ecological environment and effectively protect soil and food security. It is important to determine whether or not the SC capacity becomes stronger after the implementation of EE and whether or not EE has a notable impact on SC in different altitude zones. The exploration of the influencing mechanism and identification of the dominate influencing factors in different geographical regions needs to be improved. In this study, the soil conservation services (SCSs) from 1980 to 2020 in the Taihang Mountain area was assessed using the integrated valuation of ecosystem services and trade-offs (InVEST) model, and the spatial and temporal distributions and influencing factors were explored. The results showed the following: (1) the average SCSs exhibited an increasing trend from 1980 to 2020 on the whole, and the rate of increase reached 50.53% during the 41-year period. The rate of increase of the SCSs varied in the different EE implementation regions, and it was significantly higher than that of the entire study area. (2) The spatial distribution of the SCSs was highly heterogeneous, and the high SCS value areas were coincident with the high-altitude areas where forest and grassland occupied a large proportion. The low value areas were mainly located in the hilly zone or some of the basin regions where the proportion of construction land was relatively high. (3) The distribution pattern of the SCSs was the result of multiple factors. The EE intensity had the strongest explanatory power for the SCSs in the hilly zone, explaining 34.63%. The slope was the most critical factor affecting the SCSs in the mid-mountain and sub-alpine zones. The slope and normalized difference vegetation index (NDVI) had the greatest interactions with the other factors in the three altitude zones, especially in the high-altitude regions. The quantitative analysis of the SCSs and the influences of EE and natural factors on the SCSs revealed the heterogeneity in the mountainous areas. These results also provide a scientific basis for the reasonable implementation of EE and sustainable management of SCSs in the Taihang Mountain area.

In situ assessment of terrestrial gamma radiation dose and associated radiological hazards in Katsina State, Nigeria.

Terrestrial gamma radiation dose (TGRD) rates were measured in situ from different locations in Katsina State, Nigeria, using a portable radiation survey metre based on geological formations and soil types. The measured TGRD rates ranged from 45 to 271 nGyh-1 with an average value of 116 ± 1 nGyh-1. Geological formation (silicified sheared rock) and soil type (lithosols and ferruginous crusts and ferruginous tropical soils) appeared to have the highest mean TGRD values of 163 and 134 nGyh-1 with sandstone geological formation and alluvial and hydromorphic soils having the lowest TGRD with values of 80 and 61 nGyh-1, respectively. One way ANOVA results shows that the tested null hypothesis was rejected. Thus, indicating that there exists a strong relationship between the various geological formations, soil types with the measured TGRD values based on the alternate hypothesis. Human health hazard indices like annual effective dose equivalent (AEDE), lifetime outdoor annual equivalent dose, and relative excess lifetime outdoor cancer risk associated with the mean TGRD of the study area were also calculated and found to be 0.711, 9.955 mSv, and 5.79 × 10-4, respectively. These values were higher than the world average values but favourable compared with the safety limits recommended by ICRP.

[Characteristics of Typical Soil Acidification and Effects of Heavy Metal Speciation and Availability in Southwest China].

Using a spatial instead of temporal approach, soil samples were collected from the main types and different stages of acidification in Southwest China, and the characteristics of soil physicochemical properties, acid-buffering properties, and heavy metal fugacity patterns were analyzed, combined with biological experiments in small cabbage pots, to explore the coupling relationship between soil acidification and changes in heavy metal morphological activity. The results showed that the exchangeable salt-based ions of the soil decreased with increasing acidification in purple and yellow soils, caused by the loss of exchangeable Ca2+. The acid-buffering capacity of purple and yellow soils was higher at pH>7.50 and pH<4.50. The acid-buffering capacity of yellow soils was strongly correlated with the content of soil exchangeable salt-based ions, and the increase in acid-buffering capacity was related to the rate of depletion of soil salt-based ions with the increase in acid addition. The distribution of Cd and Pb in the soil was closely related to the soil type and degree of acidification: in the purple and yellow soils, Cd and Pb were mainly in the exchangeable and residue states, and the proportions of the exchangeable state and residue state increased and decreased, respectively, with increasing acidification; in the red soils, the residue state and Fe-Mn bound state were predominant; the Fe-Mn bound state of Cd was 2.15 and 1.73 times higher than that of the purple and yellow soils, respectively, and the Fe-Mn bound state of Pb was 4.30 and 3.91 times higher than that of purple and yellow soils, which was related to the higher iron content in red soils. Pot experiments showed that soil acidification inhibited the growth of Chinese cabbage to a certain extent, and the biomass of Chinese cabbage in the heavily acidified yellow soil (pH<5.70) was significantly lower than that in the non-acidified yellow soil.

Insights into the panorama of antibiotic resistome in cropland soils amended with vermicompost in China.

The accumulation and propagation of animal-derived antibiotic resistance genes (ARGs) pose great challenges to agricultural ecosystems. Vermicompost has drawn global attention as a new type of eco-friendly organic fertilizer. However, the effects of vermicompost application on ARGs in soil are still unclear. Here, we conducted a nationwide large-scale survey to explore the impact of vermicompost application on ARGs and the host in cropland fields as well as their regional differences. Vermicompost application was found to alter the pattern of ARGs, reduce the transfer of mobile genetic elements (MGEs), and mitigate the proliferation of high-risk bla-ARGs in soil. Regional differences in vermicompost-derived ARGs were observed in croplands, with less ARG-spreading risk in brown and yellow-brown soils. Total ARG abundance was present at the lowest level (1.24 × 105-3.57 × 107 copies/g) in vermicomposted soil compared with the croplands using animal manure (e.g., swine, chicken, and cow manure). Furthermore, vermicompost application increased the abundance of beneficial bacteria like Ilumatobacter and Gaiella, while reducing the abundance of Acidobacteria and Pseudarthrobacter. Network analysis showed that vermicompost altered ARG host bacteria and reduced the numbers of potential ARG hosts in soil. Microbes played a key role in ARG changes in vermicompost-treated soil. Our study provides valuable insight into the response of soil ARGs and the host to vermicompost in cropland ecosystem, and also provides a novel pathway for controlling the propagation of animal-derived ARGs.

Assessment of potential mobility of selected micropollutants in agricultural soils of the Czech Republic using their sorption predicted from soil properties.

The sorption of organic contaminants in soils and sediment is a crucial factor affecting their mobility in the vadose zone environment. The Freundlich sorption isotherms were evaluated for eleven micropollutants and eight soils. The highest Freundlich sorption coefficients, KF, were obtained for triclosan (324 ± 153 cm3/nµg1-1/ng-1) followed by sertraline (120 ± 74), venlafaxine (74.3 ± 41.2), telmisartan (33.3 ± 13.6), atorvastatin (8.66 ± 4.78), bisphenol S (8.03 ± 4.87), lamotrigine (6.92 ± 3.02), 2-phenylbenzimidazole-5-sulfonic acid (3.77 ± 2.25), memantine (3.42 ± 1.64), 1-methyl-1H-benzotriazole (2.05 ± 0.99), and valsartan (0.88 ± 0.89). The KF values for the individual compounds were correlated with soil properties. Multiple linear regressions were used to derive equations for predicting the KF values using the soil properties. The first set of equations contained mainly properties with the strongest correlations with the KF values, e.g., a base cation saturation for positively charged compounds or a hydrolytic acidity for negatively charged compounds. The second set of equations contained properties included in the map of agricultural soils of the Czech Republic. These equations always indicated positive correlations with oxidizable organic carbon and clay content. They also included either a negative or positive correlation with pHKCl. A positive correlation with pHKCl was obtained for venlafaxine, memantine, and sertraline, which were mostly positively charged. A negative correlation with pHKCl was obtained for the remaining compounds. The second set of equations, the soil map, and the database of soil properties were used to predict the KF value distributions within the Czech agricultural soils. It resulted in similar KF distributions' patterns for valsartan, lamotrigine, atorvastatin, and telmisartan (with a positive correlation between KF and hydrolytic acidity), which considerably differed from the KF patterns for the other compounds. These maps were used to delineate areas with a leaching potential of the compounds toward groundwater that will serve as a tool for assessing a potential groundwater vulnerability.

Impact of soil types on chemical composition of essential oil of purple basil.

Purple basil is among the most important basil varieties and its essential oil is used for several purposes including medicinal and aromatic uses. Soil types may impact the plant growth, development, and essential oil composition. Hence, it is important to find the most suitable soil type which may produce basil plants having essential oil with the best composition and concentration. For this reason, plant samples of purple basil that were grown in areas with clay, loamy sand, and sandy-clay loam soil types were collected and evaluated to determine the changes in the yield and essential oil components. Essential oil contents were determined with the Clevenger Device, and essential oil compositions were determined by using GC and GC/MS analysis. The highest essential oil yield according to soil types was obtained from the plant samples that were grown in the loamy sand soil. It was also found that the main compounds present in Arapgir town purple basil were methylcinnamate and linalool that was also present in all Turkish purple basil under all types of soil. According to the soil types, the highest concentration (46.03%) of methylcinnamate was observed in loamy sand soils, and the lowest (42.33%) was obtained from sandy-clay loam soils and found to be significantly different. Data regarding correlations between soil types and essential oil ratios showed that organic matter and P2O5 had a significant negative correlation with methylcinnamate. The present study will help researchers and farmers to choose the most suitable soil type to achieve maximum essential oil production from purple basil.

Discovery of the Relationship between Distribution and Aflatoxin Production Capacity of Aspergillusspecies and Soil Types in Peanut Planting Areas.

In order to study the relationship between the distribution and aflatoxin production capacity of Aspergillus species and soil types, 35 soil samples were collected from the main peanut planting areas in Xiangyang, which has 19.7 thousand square kilometers and is located in a special area with different soil types. The soil types of peanut planting areas in Xiangyang are mainly sandy loam and clay loam, and most of the soil is acidic, providing unique nature conditions for this study. The results showed that the Aspergillus sp. population in clay loam (9050 cfu/g) was significantly larger than that in sandy loam (3080 cfu/g). The percentage of atoxigenic Aspergillus strains isolated from sandy loam samples was higher than that from clay loam samples, reaching 58.5%. Meanwhile the proportion of high toxin-producing strains from clay loam (39.7%) was much higher than that from sandy loam (7.3%). Under suitable culture conditions, the average aflatoxin production capacity of Aspergillus isolates from clay loam samples (236.97 µg/L) was higher than that of strains from sandy loam samples (80.01 µg/L). The results inferred that under the same regional climate conditions, the density and aflatoxin production capacity of Aspergillus sp. in clay loam soil were significantly higher than that in sandy loam soil. Therefore, peanuts from these planting areas are at a relatively higher risk of contamination by Aspergillus sp. and aflatoxins.

Dynamics of fungal and bacterial communities in different types of soil ageing with different dosages of cadmium.

This study investigated the structure of fungal and bacterial communities in different types of Cd-contaminated soils. The results showed that obvious variations in microbial structure between contaminated alkaline soils and acidic soils. Proteobacteria, Gemmatimonadetes, Bacteroidetes and Basidiomycota dominated the studied communities in the alkaline soils, whereas Actinobacteria, Chloroflexi, Firmicutes, Acidobacteria, Saccharibacteria and Ascomycota were more abundant in the acidic soils. Additionally, Cd tolerant (Proteobacteria, Bacteroidetes, Ascomycota) and sensitive (Actinobacteria, Acidobacteria, Basidiomycota) in alkaline soils and JL-soils, Cd tolerant (Actinobacteria, Acidobacteria, Basidiomycota) and sensitive (Saccharibacteria, Proteobacteria, Bacteroidetes, Ascomycota, Mucoromycota) in the acidic soils were identified. Redundancy analysis and correlation analysis demonstrated that it was significantly affected by different environment parameters in alkaline soils and acidic soils. Varied bacterial community structures in all soils were dominantly influenced by pH and SOM. The similarities among different groups indicated the effect of soil type on microbial community structure was greater than that of Cd level. The above conclusions may provide a new perspective for the bio-remediation of Cd in different types of soils.

Patterns of Plumericin Concentration in Leaves of Himatanthus tarapotensis (Apocynaceae) and Its Interactions with Herbivory in the Peruvian Amazon.

We explored the concentration patterns of the bioactive metabolite plumericin produced by Himatanthus tarapotensis (Apocynaceae) under different edaphic conditions and variations in rainfall intensity, as well as its potential role in the chemical defense against insect herbivores. Values of plumericin concentration from leaves were obtained by High-Performance Liquid Chromatography, and evaluated as a function of differences in soil types, variation of precipitation, and variation of the abundance of insect herbivores, using first a Repeated Measures Correlation (rmcorr) and then a Generalized Linear Mixed Model (GLMM) analysis. Plumericin concentration is highly variable among plants, but with a significantly higher concentration in plants growing on clay soil compared to that of the white-sand soil habitat (p < 0.001). Plumericin concentration is not affected by precipitation. The caterpillar of Isognathus leachii (Lepidoptera: Sphingidae) is the most conspicuous herbivore of H. tarapotensis, and its presence is continuous but not related to plumericin concentration, probably because of its capacity to elude the chemical defense of this plant. Nevertheless, our multivariate model revealed that plumericin concentration is related to the abundance of Hymenoptera (Formicidae), and this relationship is significantly influenced by the soil parameters of carbon percentage, clay percentage, and phosphorous percentage (p < 0.001). Plumericin is a mediating agent in the interaction between H. tarapotensis and its natural environment. Variation in plumericin concentration would be induced by the abundance of Hymenoptera (Formicidae), probably as a chemical response against these insects, and by differences in soil nutrient availability.