Concentrations Of Elements In Soils Research Articles

Impact of Land Use on Peat Soil Elemental Content and Carabidae and Plant Species Composition and Abundance

This study, conducted in 2020–2022, was designed to determine the impact of livestock grazing on habitat biodiversity and Carabidae beetles. Two research plots (a meadow and a pasture) were established on a farm in the village of Otapy, located in the agricultural catchment area of the Nurzec River in Eastern Poland. They were located next to each other so that they would possess the same set of atmospheric phenomena and processes shaped by the physical and geographical characteristics of the area. The study showed that the pasture was the richest in terms of the magnesium and calcium contents, while the meadow had significantly higher levels of phosphorus and zinc. The study also showed some differences in the abundance and species composition of plants and animals. The meadow had higher biodiversity, while the pasture was dominated by grasses. A disparity in the abundance of individual species was also presented. The study indicated the preference of individual species for particular forms of land use. Anisodactylus binotatus, Harpalus rufipes and Poecilus cupreus were most abundant in the meadow, while Carabus granulatus and Pterostichus melanarius were mostly represented in the pasture. The number of species, on the other hand, was the same. Our research concluded that proper landscape management through different uses affects plant and beetle diversity and soil element content.

Toxic element characterization against a typical high geology background: Pollution enrichment, source tracking, spatial distribution, and ecological risk assessment

The geological environment determines the initial content of various elements in soil, while the late input of toxic elements produced through weathering and leaching is a persistent threat to food security and human health. In this study, we selected the Lou Shao Basin, a black rock system background, and combined geostatistical analysis and multivariate statistics to quantify the specific contribution of weathering of the black rock system, and to analyze the source traces, spatial distributions, and ecological risks of the soil toxicity of elements. The results show that the soils in the study area are acidic, which is related to the weathering of sulfides in the black rock system. The concentrations of most elements in the soil were determined to exceed the soil background values, and the Cd, Se and N contents, exceeded more than five times, especially Se, Mo nearly as high as 13 times. Strong positive correlation between Se, Cu, V and P, low correlation between N and Se, Cu, V, P, Ni and Cd.72.52%, 43%, 77.79%, 82%, 77%, and 44.1% of Cd, Se, Ni, Cu, B, and Mo came from the black rock system, respectively, which were greatly affected by geogenic weathering; V, Zn, Pb, and As are mainly from biomass burning sources; N and P are mainly from agricultural surface sources. Comparison found that the Cd and Se elements in the rocks in the study area were 16.78 times and 1.36 times higher than the world shale average, respectively, and need to pay attention to the weathering process of the two, and the spatial distribution of the 12 elements in soils showed a striped and centralized block distribution pattern, specifically around the distribution of carbonate and metamorphic rocks and other high-geology blocks. The ecological risk results showed that Cd was the main element causing high ecological risk, followed by Se and N, which were at moderate to high ecological risk levels, and Se and N showed similar ecological risk patterns, which may be related to the fact that selenium can promote the uptake and transformation of nitrogen. The present results add to the endogenous sources of toxic elements, quantify the source contributions of toxic elements in soils with high geologic backgrounds, fill this knowledge gap, and provide new insights for pollution control and ecological protection in areas with high geochemical backgrounds.

Assisting nickel agromining using sustainable amendments

AbstractOne of the challenges of agromining is the adoption of more environmentally‐friendly solutions to improve plant biomass yields and Ni concentrations in plants. Here, we focused on four sustainable solutions for optimizing nickel phytoextraction by the hyperaccumulator Odontarrhena chalcidica: a biostimulant, another biostimulant/plant defense stimulator, artificial root exudates, and a biodegradable metal chelator. Their effects on the growth and physiology of O. chalcidica, on Ni phytoextraction capacity, on physicochemical soil characteristics, and on the diversity of rhizosphere and endophytic bacteria were compared to a conventional mineral fertilizer. A 5‐month pot experiment was carried out with O. chalcidica growing on an ultramafic soil. Element concentrations in both soil and plant were measured. Moreover, numerous compounds were analyzed (photosynthetic pigments, malondialdehyde, flavonoids, free amino acids, and starch). We also characterized rhizosphere and endophytic bacterial communities associated with this hyperaccumulator. Biostimulants appeared to be a promising way of improving Ni concentration in shoots and plant biomass production, and showed a positive effect on bacterial richness and diversity. In contrast, our experiments did not show that artificial exudates and mineral fertilizer had a positive effect on Ni phytoextraction. Finally, the biodegradable chelator had no significant effect. The use of sustainable amendments into a Ni agromining system improved both plant biomass and Ni yields, in comparison to mineral fertilization. Thus, improving agromining by replacing mineral fertilizers would be an eco‐efficient strategy.

A tool for assessing the sensitivity of soil-based approaches for quantifying enhanced weathering: a US case study

Enhanced weathering (EW) of silicate rocks spread onto managed lands as agricultural amendments is a promising carbon dioxide removal (CDR) approach. However, there is an obvious need for the development of tools for Measurement, Reporting, and Verification (MRV) before EW can be brought to scale. Shifts in the concentration of mobile elements measured in the solid phase of soils after application of EW feedstocks can potentially be used to track weathering and provide an estimate of the initial carbon dioxide removal of the system. To measure feedstock dissolution accurately it is necessary to control for the amount of feedstock originally present in the sample being analyzed. This can be achieved by measuring the concentration of immobile detrital elements in soil samples after feedstock addition. However, the resolvability of a signal using a soil mass balance approach depends on analytical uncertainty, the ability to accurately sample soils, the amount of feedstock relative to the amount of initial soil in a sample, and on the fraction of feedstock that has dissolved. Here, we assess the viability of soil-based mass-balance approaches across different settings. Specifically, we define a metric for tracer-specific resolvability of feedstock mass addition (φ) and calculate the feedstock application rates (a) and dissolution fractions (b) required to resolve EW. Applying calculations of a, b, and φ to a gridded soil database from the contiguous USA in combination with known compositions of basalt and peridotite feedstocks demonstrates the importance of adequately capturing field heterogeneity in soil elemental concentrations. While EW signals should be resolvable after ~1–3 years of basalt feedstock addition at common application rates for most agricultural settings with adequate sampling protocols, resolving EW in the field is likely to be challenging if uncertainties in tracer concentrations derived from field-scale heterogeneity and analytical error exceed 10%. Building from this framework, we also present a simple tool for practitioners to use to assess the viability of carrying out soil-based EW MRV in a deployment-specific context.

Warming affects leaf light use efficiency and functional traits in alpine plants: evidence from a 4-year in-situ field experiment.

Light use efficiency (LUE) is a crucial determinant of plant productivity, while leaf functional traits directly affect ecosystem functions. However, it remains unclear how climate warming affects LUE and leaf functional traits of dominant species in alpine meadows. We conducted a 4-year in-situ field warming experiment to investigate the eco-physiological characteristics for a dominant species (Elymus nutans) and a common species (Potentilla anserina) on the Tibetan Plateau. The leaf traits, photosynthesis and fluorescence characteristics were measured, along with the soil physical-chemical properties associated with the two species. Experimental warming increased the leaf LUE, maximum photochemical efficiency, non-photochemical quenching, relative water content and specific leaf area for both species. However, there was a decrease in leaf and soil element content. Different species exhibit varying adaptability to warming. Increasing temperature significantly increased the photosynthetic rate, stomatal conductance, transpiration rate, total water content, and specific leaf volume of E. nutans; however, all these traits exhibited an opposite trend in P. anserina. Warming has a direct negative impact on leaf LUE and an indirectly enhances LUE through its effects on leaf traits. The impact of warming on plant photosynthetic capacity is primarily mediated by soil nutrients and leaf traits. These results indicate that the two different species employ distinct adaptive strategies in response to climate change, which are related to their species-specific variations. Such changes can confer an adaptive advantage for plant to cope with environmental change and potentially lead to alterations to ecosystem structure and functioning.

Effects of plant growth-promoting rhizobacteria on blueberry growth and rhizosphere soil microenvironment.

Plant growth-promoting rhizobacteria (PGPR) have a specific symbiotic relationship with plants and rhizosphere soil. The purpose of this study was to evaluate the effects of PGPR on blueberry plant growth, rhizospheric soil nutrients and the microbial community. In this study, nine PGPR strains, belonging to the genera Pseudomonas and Buttiauxella, were selected and added into the soil in which the blueberry cuttings were planted. All the physiological indexes of the cuttings and all rhizospheric soil element contents were determined on day 6 after the quartic root irrigation experiments were completed. The microbial diversity in the soil was determined using high-throughput amplicon sequencing technology. The correlations between phosphorus solubilization, the auxin production of PGPR strains, and the physiological indexes of blueberry plants, and the correlation between rhizospheric microbial diversity and soil element contents were determined using the Pearson's correlation, Kendall's tau correlation and Spearman's rank correlation analysis methods. The branch number, leaf number, chlorophyllcontentand plant height of the treated blueberry group were significantly higher than those of the control group. The rhizospheric soil element contents also increased after PGPR root irrigation. The rhizospheric microbial community structure changed significantly under the PGPR of root irrigation. The dominant phyla, except Actinomycetota, in the soil samples had the greatest correlation with phosphorus solubilization and the auxin production of PGPR strains. The branch number, leaf number, and chlorophyllcontent had a positive correlation with the phosphorus solubilization and auxin production of PGPR strains and soil element contents. In conclusion, plant growth could be promoted by the root irrigation of PGPR to improve rhizospheric soil nutrients and the microenvironment, with modification of the rhizospheric soil microbial community. Plant growth could be promoted by the root irrigation of PGPR to improve rhizospheric soil nutrients and the microenvironment, with the modification of the rhizospheric soil microbial community. These data may help us to better understand the positive effects of PGPR on blueberry growth and the rhizosphere soil microenvironment, as well as provide a research basis for the subsequent development of a rhizosphere-promoting microbial fertilizer.

Biochemical and allelopathic features of Adonis vernalis, Allium ursinum, and Leucojum vernum in the M.M. Gryshko National Botanical Garden of the NAS of Ukraine

The article presents the results of a study on the content and dynamics of the accumulation of biogenic elements and brassinolides in plants of Adonis vernalis, Allium ursinum, and Leucojum vernum in Kyiv, Ukraine. Data is provided on allelopathic activity, content of macro- and microelements, phenolic compounds, and laccase activity in plants and the rhizosphere soil under the conditions of the M.M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine (NBG). The plants from the collection of the NBG were used as objects of study in field experiments. The content of biogenic elements in plant tissues and soil was analyzed using an inductively coupled plasma spectrometer. The allelopathic analysis of soil was conducted using a direct bioassay method with Lepidium sativum seedlings as the test object. Phenolic compounds were extracted from the soil using the ion exchange (desorption) method. The content of brassinosteroids was measured spectrophotometrically at a wavelength of 450 nm. The content of laccase was measured spectrophotometrically at a wavelength of 530 nm.The results demonstrate that model plant species employ a wide range of physiological mechanisms throughout the vegetation period to enhance their resistance to abiotic factors. These mechanisms include maintaining potassium and calcium balance and utilizing hormonal compounds. Plants have been proven to have compensatory mechanisms in response to stress factors, substituting one biochemical marker of resistance with another. Both, brassinosteroids and silicon, contribute to the adaptive capacity of organisms.

A preliminary study on heavy metal monitoring in soil and guar (Cyamopsis tetragonoloba) biomass amended with sewage sludge.

Applying sewage sludge in agricultural soils is an interesting source of organic matter. This study aimed to monitor concentrations of heavy elements in soil and guar plants, which can pose a risk to the health of humans and animals if they enter the food chain through the soil-plant system. The experiment revealed that applying sludge increased the amount of organic matter, total nitrogen, potassium, and phosphorus in the soil. Additionally, the concentration of heavy metals such as Pb, Co, Cr, Ni, Cu, and Zn in all treatments remained below the permissible limits for soil. The highest plant height and plant dry weight were recorded in the sludge and sludge + fertilizer treatments. The dry weight of the guar varied from 629 g m-1 in the control treatment to 1050 g m-1 in the sludge + fertilizer plots. The use of sludge increased the accumulation of heavy metals in the above-ground parts of the guar plant compared to the control. However, the level of heavy metal remained within the normal range and below the toxic concentration. Our results also showed that the application of sludge along with fertilizer improved the quality of the guar forage by increasing the levels of crude protein, digestible dry matter and water-soluble carbohydrates. Overall, the results indicated that using sludge as organic fertilizer can improve soil properties, reduce the use of inorganic fertilizers, and decrease the harmful effects of heavy metals on the environment and health in the research area.

The influence of the environmental factors on the accumulation patterns of toxic elements in Plantago lanceolata sampled in the area under strong anthropopressure

The study aims to explore the environmental factors which activate accumulation abilities of Plantago lanceolata in the research area under strong anthropopressure resulting from the long-term pollution originating from copper mining-metallurgical activities in Southeastern Europe. Sampling was performed at the most endangered sites regarding its proximity to the major and/or secondary pollution sources, as well at the control site. The content of toxic elements (Al, Cu, Fe, Mn, Ni, Pb and Zn) was determined in the roots, leaves, stalks and flowers of P. lanceolata. The anthropogenic origin of environmental contamination was denoted through the high concentrations of Cu, Pb and Zn in the leaves of P. lanceolata, reaching toxic levels, combined with the enrichment of plant parts (Enrichment factor >2), especially with Cu (as well as with Al, Fe, Ni and Zn) in samples from the immediate proximity to the copper smelter or at the prevailing wind directions. Biomonitoring potential, assessed through the correlations between toxic element content, as well as the values of Enrichment factor, was indicated for roots (in the case of Cu), all the aboveground plant parts (Fe) and stalks (Zn). The results have shown that the contents of toxic elements in plant parts as well as phytoremediation of P. lanceolata were dependent on soil element content, soil physico-chemical properties and soil enzyme activities, which were regarded as the main environmental drivers affecting phytoremediation ability. The analysis of biological factors (bioconcentration, translocation and bioaccumulation factor) indicated exclusion strategy and possible usage of P. lanceolata in phytostabilization of Zn. The results indicated that the study area is 'environmental hotspot' with potential threat to human health due to the high levels of bioaccumulation of the investigated toxic elements in P. lanceolata parts.

Element accumulation by the holoparasitic species Cuscuta planiflora from serpentines in Bulgaria

AbstractThe holoparasitic species Cuscuta planiflora Ten. (Convolvulaceae) parasitizes the Ni hyperaccumulator Odontarrhena muralis (Waldst. & Kit.) Endl. and a non‐hyperaccumulator, Sanguisorba minor Scop., in Bulgarian serpentine areas. This study investigated the host/parasite relationship to evaluate: (1) metal accumulation in different parts of the parasite and the host and (2) its potential threat to Ni phytomining/agromining by suppressing growth of the hyperaccumulator. Elemental concentrations in soil, shoots, leaves, and inflorescences of the two host plants, and in shoots and inflorescences of the parasite, were determined. Elemental concentrations of Ca, Mg, Fe, Ni, Cr, Co, Zn, Cu, Mn, Cd, and Pb were determined after microwave digestion using inductively coupled plasma—optical emission spectrometry (ICP‐OES) under optimal instrumental parameters. Individuals of hosts, both infected and non‐infected, differed in the concentrations of essential elements (P, K) and some micronutrients. Infected individuals of O. muralis showed lower Ni concentrations in shoots, leaves, and inflorescences compared to non‐infected ones. Sanguisorba minor is an excluder plant with low tissue Ni concentrations. The parasite had higher P and K, and lower Ca, Mg, Ni, Zn, Co, and Mn concentrations, than the host. The highest Ni concentration measured in the shoots of C. planiflora was 279 mg kg−1, whereas that from S. minor was 29.9 mg kg−1. Element transfer from host to parasite appeared element‐specific and after infection Ni concentrations in all organs and biomass of hosts were reduced. We conclude that infection by C. planiflora is a potential threat to use of O. muralis for Ni agromining.

Concentration, speciation, and fractionation of rare earth elements in alluvial soils in contiguous karst landform, southwestern China

Karst is a unique landform formed by strong chemical weathering of carbonate rocks. This study investigated the concentration and speciation of rare earth elements and yttrium (REY) in alluvial soils and REY fractionation from carbonate rocks and alluvial soils in the world's largest contiguous karst landform in southwestern China. The results showed that the REY of alluvial soils ranged from 73.77 to 1251.56 μg⋅g−1, with a median value of 230.30 μg⋅g−1, which was higher than that of alluvial soils across China (178 μg⋅g−1) and the upper continental crust (168 μg⋅g−1), revealing a high background of REY in these karst areas. Meanwhile, the average REY in alluvial soils (244.96 μg⋅g−1) was close to 14 times that in carbonate rocks (17.61 μg⋅g−1) in the study area, indicating that REY was significantly enriched in the pedogenesis. Correlation analysis showed that the REY concentration was not significantly related to any single factor (i.e., Fe2O3, MnO, Al2O3, TOC, pH, or CIX). BCR speciation analysis revealed a declining trend in the proportion of REY across the residual (F4, 73.21 %), reducible (F2, 19.40 %), oxidizable (F3, 6.89 %), and weakly acid-extracted (F1, 0.50 %) phases. Additionally, significant REY fractionations from carbonate rocks to alluvial soils were observed. The bedrock-normalized REY pattern revealed an enrichment of light rare-earth elements (LREE) and middle rare-earth elements (MREE), a depletion of heavy rare-earth elements and yttrium (HREY), and positive Ce and Gd anomalies. Secondary mineral phases that formed during weathering—such as clay minerals, oxyhydroxides, phosphates, and organic matter—played an important role in the retention and fractionation of the REY in the soils. Besides these natural factors, anthropogenic inputs also contributed to the REY fractionation, as indicated by the slight positive Gd anomaly in the karst alluvial soils. Furthermore, the differences of δCe and δEu in the soils developed from three types of pedogenic rocks—including carbonate, basalt, and granite—were discussed. The different δEu anomalies could help to identify the parent rocks of alluvial soils.

Biomonitoring of Potentially Toxic Elements in an Abandoned Mining Region Using Taraxacum officinale: A Case Study on the “Tsar Asen” Mine in Bulgaria

Mining is a significant industrial and economic activity, but it can also result in ore waste that contains several potentially toxic elements (PTEs). Furthermore, the wide range of observed transfer and accumulation factors suggests that not only the soil element concentrations but also the soil characteristics are important for uptake, which is recognized as a serious problem with potential impacts on human health and ecosystems. The aim of this study was to perform a pollution risk assessment of a region near an abandoned mine using suitable biomonitoring followed by multivariate statistical treatment of the obtained results. The content of PTEs in the soil and plant samples was determined to exceed the background concentrations typical for Bulgaria. The observed concentrations of copper in this study’s soil samples exceeded 2 to 16 times the maximum permissible values. The Taraxacum officinale concentrations for PTEs, particularly for Cd (5.13 mg/kg), were higher than the background levels. The obtained results for PTEs show significant TFs for Cd and Sn, while the AFs outline a significant accumulation of Cd and Sb. The applied multivariate statistical approaches revealed differences between the sampling locations and relationships between the elemental transfer/accumulation factors and soil cation exchange capacity. The outcomes from the statistical analysis confirm that the usage of both element factors and soil properties in biomonitoring studies are essential for reliable risk assessment.

Homeostatic evidence of management-induced phosphorus decoupling from soil microbial carbon and nitrogen metabolism

Abstract The theory of microbial stoichiometry can predict the proportional coupling of microbial assimilation of carbon (C), nitrogen (N), and phosphorus (P). The proportional coupling is quantified by the homeostasis value (H). Covariation of H values for C, N, and P indicates that microbial C, N, and P assimilation are coupled. Here, we used a global dataset to investigate the spatiotemporal dynamics of H values of microbial C, N, and P across biomes. We found that land use and management led to the decoupling of P from C and N metabolism over time and across space. Results from structural equation modeling revealed that edaphic factors dominate the microbial homeostasis of P, while soil elemental concentrations dominate the homeostasis of C and N. This result was further confirmed using the contrasting factors on microbial P vs. microbial C and N derived from a machine-learning algorithm. Overall, our study highlights the impacts of management on shifting microbial roles in nutrient cycling.

Effects of vegetation restoration on the concentrations of multiple metal elements in post-mining soils

Vegetation restoration is vital for soil ecological restoration in post-mining areas, but a global-scale quantitative assessment of its effects on soil metal elements is lacking. Here, we conducted a meta-analysis with 2308 paired observations collected from 137 publications to evaluate vegetation restoration effects on the concentrations of 17 metal elements, namely K, AK (available K), Ca, Na, Mg, Fe, Mn, Zn, Cu, Al, Cr, Co, Ni, Cd, Sb, Hg, and Pb in post-mining soils. We found that (1) vegetation restoration significantly increased the concentrations of K, AK, Ca, Mg and Co by 43.2, 42.5, 53.4, 53.7, and 137.2%, respectively, but did not affect the concentrations of Na, Fe, Mn, Zn, Cu, Al, Cr, Ni, Cd, Sb, Hg, and Pb; (2) the effects of vegetation restoration on soil metal concentration were seldom impacted by vegetation type, while soil depth only affected the responses of AK, Cd, and Pb concentrations to vegetation restoration, and leaf type only impacted the responses of Ca and Ni concentrations to vegetation restoration; (3) latitude, elevation, restoration year, climate, and initial soil properties were also important moderator variables of vegetation restoration effects, but their impacts varied among different metals. Overall, our results clearly showed that vegetation restoration in posting-mining areas generally have a positive effect on the concentrations of nutrient elements but did not influence that of toxic elements, which provides useful information for the restoration and reconstruction of soil ecosystem in post-mining areas.

Chronic drought alters extractable concentrations of mineral elements in Mediterranean forest soils

Soil mineral elements play a crucial role in ecosystem productivity and pollution dynamics. Climate models project an increase in drought severity in the Mediterranean Basin in the coming decades, which could lead to changes in the composition and concentrations of mineral elements in soils. These changes can have significant impacts on the fundamental processes of plant-soil cycles. While previous studies have predominantly focused on carbon, nitrogen, and phosphorus, there is a notable lack of research on the biogeochemical responses of other mineral elements to increasing drought. In this study, we investigated the effects of chronic drought (15 years of experimental rainfall exclusion) and seasonal drought (summer period) on the extractable soil concentrations of 17 mineral elements (arsenic (As), calcium (Ca), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), sulphur (S), strontium (Sr), vanadium (V) and zinc (Zn)) in a Mediterranean holm oak forest. We also explored the potential biotic and abiotic mechanisms underlying the changes in extractable elemental concentrations under chronic drought conditions. Our findings reveal that soil elemental concentrations varied significantly due to seasonal changes and chronic drought, with soil microclimate, biological activity, and organic matter being the main drivers of this variability. Levels of soil water content primarily explained the observed variations in soil elemental concentrations. Most of the mineral elements (13 out of 17) exhibited higher concentrations during winter-spring (wet seasons) compared to summer-autumn (dry seasons). The chronic drought treatment resulted in K limitation, increasing vegetation vulnerability to drought stress. Conversely, the accumulation of S in soils due to drought may intensify the risk of S losses from the plant-soil system. Under drought conditions, certain trace elements (particularly Mn, V, and Cd) exhibited increased extractability, posing potential risks to plant health and the exportation of these elements into continental waters. Overall, our results suggest that alterations in mineral element concentrations under future drier conditions could promote ecosystem degradation and pollution dispersion in the Mediterranean Basin. Understanding and predicting these changes are essential for effective ecosystem management and mitigating the potential negative impacts on plant health and water quality.

Distribution characteristics of selenium and heavy metal elements in soil-crop system in ankang, shaanxi, china

A total of 229 groups of root vegetables, rice, corn and their root soils were collected in Ankang, Shaanxi, to analyze the characteristics of element migration and transformation in crops and root soil, to compare the migration and enrichment capabilities of various elements in different crops, to explain the characteristics of root soil pH and element correlation, and provide a theoretical basis for agricultural development. Results showed that there were differences in the ability of crops to accumulate various elements in the soil. The absorption capacity of Se, Cd and Zn elements was strong, while the bioaccumulation ability of As, Pb and Cr elements was weak. The contents of Cr, As and Hg were the highest in rice, which were significantly higher than those in root vegetables and corn. The contents of Cd, Cu and Pb in root vegetables were the highest, significantly higher than those in rice and corn. The content of various elements in crops and root soil had a different intensity correlation. Generally speaking, the content of various elements in crops increased with the increase of root soil element content to a certain extent. There was a negative correlation between pH and soil elements, and there was a significant positive correlation between the elements in the root soil of different crops. Bangladesh J. Bot. 52(2): 649-657, 2023 (June) Special

Distribution characteristics of selenium and heavy metal elements in soil-crop system in ankang, shaanxi, china

A total of 229 groups of root vegetables, rice, corn and their root soils were collected in Ankang, Shaanxi, to analyze the characteristics of element migration and transformation in crops and root soil, to compare the migration and enrichment capabilities of various elements in different crops, to explain the characteristics of root soil pH and element correlation, and provide a theoretical basis for agricultural development. Results showed that there were differences in the ability of crops to accumulate various elements in the soil. The absorption capacity of Se, Cd and Zn elements was strong, while the bioaccumulation ability of As, Pb and Cr elements was weak. The contents of Cr, As and Hg were the highest in rice, which were significantly higher than those in root vegetables and corn. The contents of Cd, Cu and Pb in root vegetables were the highest, significantly higher than those in rice and corn. The content of various elements in crops and root soil had a different intensity correlation. Generally speaking, the content of various elements in crops increased with the increase of root soil element content to a certain extent. There was a negative correlation between pH and soil elements, and there was a significant positive correlation between the elements in the root soil of different crops. Bangladesh J. Bot. 52(2): 649-657, 2023 (June) Special

The evaluation of potentially toxic elements using artificial neural networks and fuzzy linear regression analysis methods in cappadocian volcanic ash soils of Turkey

The aim of this study is to determine the relationships between some potentially toxic elements (PTE) (Cu, Mn, Ni, Zn) in human stomach and intestinal tissues and toxic element contents in soil, vegetables and fruits. This study was conducted in the eastern of Erciyes Strato volcano, an area of 2400 km2 in Turkey. Tissue samples taken from the stomach and intestines of people living in the study area, soils, vegetables, and fruits were used as material. In the study, tissue samples of 26 people's stomach and intestines, 576 soil samples from 192 points and 3 different depths (0–30 cm, 30–60 cm, and 60–90 cm) and vegetable and fruit samples from 137 sampling points were taken. Cu, Mn, Ni, and Zn contents of human tissue samples, soil samples, vegetable and fruit samples were determined. Artificial Neural Networks method (ANN) and Fuzzy Linear Regression Analysis (FLRA) methods were used to determine the relationships between PTE contents in human tissue samples and soils, vegetables, and fruits. Root Mean squared error (RMSE) and coefficient of determination (R2) indices were used as the test criteria for goodness of fit. When compared with ANN method, it was determined that PTE values in stomach and intestinal tissue estimated by FLRA method had the lowest error and high R2 values. It was found that the most effective variable in estimating the average PTE value in stomach and intestinal tissue is PTE values in soil. It was determined that the FLRA regression analysis method has a better predictive power than the ANN method. Using FLRA and ANN regression methods, it was determined that there is a statistically high relationship between PTE contents in soils and stomach and intestinal tissues. It is recommended to make the study findings more meaningful with effective and reliable service planning by using different regression analysis methods in ecological and clinical studies.

Effect of struvite (Crystal Green) fertilization on soil element content determined by different methods under soybean cultivation

Struvite is regarded as a promising phosphorus fertilizer alternative to mineral fertilizers; however before fertilizing, soil tests should be undertaken to determine fertilizer recommendations. In May 2022, soil was sampled from a pot experiment with the application of phosphorus set up at the Wroclaw University and Environmental and Life Sciences. Chemical analysis of the soil included total and available phosphorus, potassium, magnesium determined by the Egner–Riehm, Mehlich 3 and Yanai methods. The purpose of the article is to compare soil element extraction by three different methods under struvite fertilization and its use in soybean cultivation. The application of these methods indicated an unambiguous increase in soil Mg content after struvite application. Broadcast soybean fertilization affected the phosphorus content of the soil. The results of the study indicated that different extraction methods presented different contents of P from soil. The content of available phosphorus was circa 122–156 mg kg−1 dm, 35.4–67.5 mg kg−1 dm and 100–159 mg kg−1 dm according to the Mehlich, Yanai and Egner–Riehm methods, respectively. A positive correlation was found between the content of Mg and K in soil determined by the Mehlich 3 and Yanai methods, which may suggest that the Yanai method could be introduced into standard soil chemical analysis in Poland. Such a correlation was not found for phosphorus, which is a difficult element to determine due to the multitude of factors affecting its availability.

Different responses of soil element contents and their stoichiometry (C: N: P) to different grazing intensity on the Tibetan Plateau shrublands

Potentilla fruticosa, a major alpine shrubland type, is widely distributed across the Tibetan Plateau, and grazing is the most common disturbance in the shrublands of P. fruticosa. However, soil organic carbon (SOC), soil total nitrogen (STN), soil total phosphorus (STP), and their stoichiometry under different grazing intensities were unclear. In our study, we explored SOC, STN, STP, their stoichiometry, and their controlling factors in the grazing disturbance of heavy grazing (HG), moderate grazing (MG), light grazing (LG), and no grazing (NG) conditions in the Tibetan Plateau P. fruticosa shrublands. The grazing intensities were mainly assessed by considering the shrublands’ ground cover, the indicators of the road density, the distance between sampling sites and cowshed or sheep shed, the amounts of cow and sheep dung, and vegetation that had been gnawed and stampeded. Our results indicated that soil physical properties of soil temperature and bulk density have decreasing trends with decreasing grazing intensities from HG to NG. The SOC, STN, STP, and soil C:N and C:P ratios have increasing trends with decreasing grazing intensities from HG to NG, while the changes in soil N:P ratio were relatively stable along grazing intensities. Our results indicated that HG generally had stronger effects on SOC, STN, and soil C:N and C:P ratios than NG, indicating substantial effects of grazing disturbance on biogeochemical cycles of SOC and STN in the shrubland ecosystems. Therefore, for the alpine shrubland of P. fruticosa, the HG should be avoided for sustainable cycling of soil nutrients and the balance of soil nutrient stoichiometry. The grazing types can directly affect plant conditions, and plant conditions can directly affect soil physical and chemical properties and litter standing crops. Finally, soil physicochemical properties and litter standing crop resulting from different grazing intensities directly control SOC, STN, and STP. For the soil stoichiometry, the soil’s physical and chemical properties resulting from different grazing intensities have direct impacts on soil C:P and N:P ratios.