Patterns in trace elements in lichens

Water, Air, & Soil Pollution - Epiphytic lichens were sampled in a Dutch national monitoring survey, which was carried out twice within 5 yr. The samples were analyzed by neutron activation...     

Field-based partition coefficients for trace elements in soil solutions

A total of 48 elements was detected in the soil solutions centrifuged from two acid sandy (humus-iron podzol) profiles from southern England. Concentrations ranged from mm for the major ions to mm for trace metals such as U and the rare earth elements. Field-based solid/solution partition coefficients, K_d, were determined by calculating the ratio of the amount of an element extracted by 0.43 m HNO₃ or a neutral salt (0.01 m CaCl₂ or 0.1 m Ba(NO₃)₂) to the concentration in the soil solution. These partition coefficients did not show the expected trend in selectivity. For example, Cd consistently had one of the highest K_d values, higher even than Cu. This was thought to be due in part to the nature of the K_d which reflects a balance between binding to the soil solids and to the dissolved organic carbon (DOC), which is present at relatively high concentrations (1–20 mm ) in the soil solutions. Because of the underlying functional similarity between metal binding by the solid and dissolved organic matter, the partition coefficient (and hence element mobility) will be relatively insensitive to changes in pH and metal-ion activity in the soil solution.     

Rare earth elements and other trace elements in wastewater treatment sludges

In order to evaluate the possibility of contamination of soil with trace elements by the application of sludges to soil, the contents of rare earth elements (REEs; La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and other trace elements (Be, As, Ag, Cd, Sb, Cs, Bi, and U) in wastewater treatment sludges were determined. In sludges of night soil treatment plants (night soil sludges) and sludges of wastewater treatment plants in the food industry (food industry sludges), the distribution patterns of REEs normalized versus average REEs in the continental crust were almost flat. It was considered that the REE patterns of uncontaminated sludges reflected the pattern of the continental crust. The crust-normalized REE patterns of sludges of wastewater treatment plants in the chemical industry (chemical industry sludges) and municipal sewage sludges did not always show flat plots. The sludges that did not show a flat REE pattern were considered to be contaminated with some of the REEs.

The coefficient of variation of each element determined among the 10 samples of night soil sludges and the 14 samples of sewage sludges ranged from 34 to 77% and from 26 to 84%, respectively. Among the 10 samples of food industry sludges and the 10 samples of chemical industry sludges, the coefficient ranged from 60 to 143% and from 67 to 172%, respectively. The variations of the content of each element among the food industry sludges or the chemical industry sludges were larger than those among the night soil sludges or the sewage sludges.

The contents of Be, As, Cs, REEs, and U in all the sludges were lower than or the same as those in a field soil. Some of the food and chemical industry sludges contained larger amounts of Ag, Cd, and Sb than the soil. All the night soil sludges and sewage sludges contained much larger amounts of Ag and Bi than the soil.     

Trends in Sulfur Emission-Induced Effects in Northern Europe

Fennoscandia is subjected to a considerable anthropogenic load, where S still is a notable contributor. At the same time, the region is very sensitive to acidifying depositions. The Regional Acidification Information and Simulation model (RAINS) was applied for a regional assessment of S deposition and loads in Fennoscandia from 1960 through 1995. Different variants of sources were considered: 1) all Europe, 2) north-west Russia (the Kola, Karelia and Leningrad county), and 3) the Nordic countries (Finland, Norway, Sweden). This allowed their contribution to the deposition pattern of the region to be assessed. The percentage of the ecosystems where the critical load had been exceeded was calculated for each year. For a more detailed assessment of the influence of the sources of the Kola region, estimations on the basis of local and meso-scale models were made. Comparative analysis of the calculations for the domestic and all the European sources revealed a dominating effect of S deposition from west and central Europe (Europe minus Fennoscandia) in general. The calculations showed a high, but local impact of the Kola sources on northern parts of the Fennoscandian region.     

Crop contamination by selected trace elements

Goal and Background  The regulatory limit for the allowable concentration of heavy metals (HM) in agricultural soils should be based both on HM status and on soil parameters that influence HM mobility. In this paper, a soil categorization scheme is proposed which is based on the main factors that influence HM mobility in soils. The scheme also makes use of the existing regulatory limits for total concentrations of trace elements in Slovak soils but additionally takes into account the potential ability of the soils to mobilize trace elements. A map of the Slovak Republic showing the soil categorization using this scheme is presented. Methods  Besides total soil content of Cd, Pb, Cr, Hg, As, Cu, Zn, Ni, soil parameters with dominant influence on HM mobility are included in the scheme pH, organic matter content, quality of humus represented by spectral parameter Q⁴ ₆ and content of fraction f < 0.01 mm. Point rating approach was used for categorization. Database of localized soil data from 3556 locations was used for creation of map in GIS environment. Results  Based on the point scoring method described herein, soils are ranked from a (the least risk of crop contamination) to d (medium risk). Categories e and f are reserved for soils where the risk exceeds the allowable regulatory limits. For each of the six categories, the most suitable usage of agricultural land is recommended. The Slovak map presented shows that the main factor that affect the spatial distribution of each soil category is soil parent material which governs the existing total HM content and the predisposition for certain soil types to have high HM mobility. Agricultural usage of land in Slovakia is in most cases limited by exceedences of Cr and Ni, originating from widespread flysch rock parent material. Conclusions  Application to regional geochemical data shows that, for more than half of Slovak agricultural land, risk of crop contamination is low. For the rest of the area, planting should consider sensitivity of crops to HM uptake. Recommendation and Outlook  Evaluation of suitable agricultural usage based on HM contamination risk, should include not only the total HM content but also the potential for HM mobility, which can increase the risk of plant contamination. Where HM mobility data are not available, soil parameter data that influence HM mobility can be used to predict the potential HM soil contamination hazard.     

Trace elements in some Northern Nigerian soils

Abstract

The concentrations of the more‐or‐less strongly retained trace elements present in the root zone of some northern Nigerian soils were determined. The soils were chosen to represent some of the more extensively distributed soil orders under cultivation in the Nigerian savanna zone. Extraction by concentrated HNO₃ was used to determine the so‐called “total”; amount of retained Cu, Zn, Pb, Ni, Cd, and B in the soils. Aqueous solutions of the chelating agents, EDTA and DTPA, were used to extract the more weakly retained Cu, Zn, Pb, Ni, and Cd; whereas, hot water was used to extract the weakly retained B. The “total”; and the more‐weakly‐retained contents of these trace elements were significantly correlated with the amount of clay, silt, and the oxalate‐extractable oxyhydroxides present in the soils; whereas, only the weakly retained elements were significantly correlated with the content of organic matter in the soil. Both the “total”; concentrations and weakly‐retained Cu, Zn, and B were so low that deficiency problems may develop in these sandy soils if cultivated more intensively on a commercial scale without due precautions. The concentrations of the weakly‐retained toxic elements, Pb, Ni, and Cd, were low indicating that industrial pollution has not yet occurred.     

用微量元素对东北大米产地识别的技术

为探讨元素指纹分析技术对东北三省大米产地识别的可行性,筛选出可以区分不同产地大米的标志元素,该研究采用电感耦合等离子体质谱（Inductively Coupled Plasma Mass Spectrometry,ICP-MS）测定东北三省主要水稻产区土壤-作物籽实中Li、B、Be等23种微量元素含量,利用相关分析、方差分析、偏最小二乘回归分析等多种分析方法对不同产地大米及土壤中微量元素含量进行分析,建立识别东北三省大米产地的判别模型。结果表明：大米中Mo、Zn含量与土壤中Mo、Zn含量呈显著正相关（P<0.01）;3个省份大米中Ga、Pb、Sr、Zr、Ba元素分布表现出一致性,而另外18种元素表现出显著差异性（P<0.05）。对18种显著差异元素建立产地识别模型,发现正交偏最小二乘回归分析和多层感知器神经网络分析建立的判别模型能较好地对东北三省大米进行有效区分和识别,多层感知器神经网络分析中整体检验组的综合正确判别率为96.3%;在Fisher判别分析中利用逐步判别法筛选出的7种元素建立的判别模型能有效识别东北三省大米产地,判别正确率为93.8%。研究表明基于微量元素含量...     

Principal component analysis of trace elements in Serbian wheat

Trace elements (Cu, Fe, Pb, Hg, Cd, As, Mn, Zn) were analyzed quantitatively in 14 wheat samples collected from fields in all Serbian growing regions, harvested in 2002. Microelements were determined according to an atomic absorption spectrophotometric method. Principal component analyses (PCA) were performed on data matrices consisting of contents of trace elements in wheats (columns) and all Serbian wheat-growing regions (rows). It was found that four principal components account for 87.2% of the total variance in the data. The plot of component loadings showed significant groupings for concentration of some microelements. The component scores indicated the similarities among the Serbian wheat-growing regions. The loading plot reveals that there is no need to measure all of the variables to achieve the same classification. It is enough to measure one variable per group. Naturally, this conclusion is valid only within the limits of the present study of wheat grain samples from different parts of Serbia.     

Effects of trace elements on urease activity in soils

Disposal of sewage sludges and effluents on agricultural land is becoming a widespread practice. Most sludge samples disposed on soils contain large quantities of various trace elements. Studies of 20 trace elements commonly found in sludge samples showed that they inhibit the activity of urease in soils and that their order of effectiveness as inhibitors of urease depends on the soil. When the trace elements were compared by using 5 μmiol·g^?1 soil, however, some of them showed the same order of effectiveness as urease inhibitors in the six soils studied i.e., for the monovalent and divalent ions, Ag⁺ ≥ Hg²⁺ >Cu²⁺ >Cd²⁺ >Zn²⁺ >Sn²⁺ >Mn²⁺, and generally, Fe²⁺ >Fe²⁺andCu²⁺ >Cu⁺. Other trace element ions that inhibited urease were Ni²⁺, Co²⁺, Pb²⁺, Ba²⁺, As³⁺ B³⁺, Cr³⁺, Al³⁺. V⁴⁺ Se⁴⁺ and Mo⁶⁺. Of the trace element ions studied, only As⁵⁺ and W⁶⁺ did not inhibit urease activity in soils.Studies on the distribution of urease activity showed that it is concentrated in surface soils and decreases with depth. Urease activity was proportional to organic C distribution in each soil profile and was significantly correlated with organic C in the surface soils studied.     

Characterization of major and trace elements in sclerotium grains

Sclerotium grains in soil contain humus-metal complexes that are probably produced from fungal metabolites. The characterization of major elements in sclerotium grains collected from volcanic ash soils in Mt Myoko was examined by X-ray photoelectron spectroscopy, FT-IR spectrometry and CHN analysis, and the concentration of trace elements was determined by PIXE (particle induced X-ray emission spectrometer) analysis. The content of major elements, C, H, N, O and Al, was approximately 47.6, 3.32, 0.78, 30.2 and 1.4% by mass, respectively. Trace elements such as Ti, Cr, Mn, Cu, Zn, Br and Pb were detected in the grains at concentrations between 10 and 100 μg g⁻¹. Functional carbon groups for the whole grain were characterized by the dominance of O-alkyl C associated with aromatic C. The comparison between the surface and subsurface (matrix) of the grain showed that the concentrations of O, C and N were relatively greater on the surface of sclerotium grains than in the matrix. The proportion of carbon having C–O, C=O, and O–C=O bonds, O and N showed a tendency to decrease from the surface towards the matrix. The proportion of C assigned as C–C and/or C–H bonds had a tendency to increase towards the matrix associated with Al.     

土垫旱耕人为土中某些痕量元素的迁移富集特征及其成因

土壤中元素的分布特征反映了多个成土因素综合作用下土壤发生过程的结果。为探讨人为因素和自然成土因素在土垫旱耕人为土(塿土)形成过程中的影响,本研究在黄土高原区关中平原西部的渭河三级阶地上采集两个典型的土垫旱耕人为土剖面,以马兰黄土作为成土强度的参照样品,采用Zr作为稳定元素,研究痕量元素Cu、Zn、Pb、Rb、Sr的分布特征及其成因。结果表明,受介质的吸附、碳酸钙等易淋溶组分的淋溶淀积、作物吸收等因素影响,痕量元素Cu、Zn、Pb、Rb在剖面上总体呈中高型分布,即在干润淋溶土表层(2A层)和黏质化B层(2B t层)含量有所增加而表现为富集;而Sr则发生强烈迁移,在2A层、2B t层含量显著降低。在埋藏耕作层(Aupb层)、亚耕层(Aup2层)和现代耕作层(Aup1层),自下而上,Cu、Zn、Pb的含量呈缓慢增加趋势,但只有Zn的富集系数在YL01剖面0~15 cm内大于1.1,说明土壤发生过程是导致土垫旱耕人为土剖面中某些层次元素相对富集的主要原因,而人类活动对土垫旱耕人为土痕量元素的影响很弱,且主要在表层。     

Evaluation of the BCR sequential extraction for trace elements in European reference volcanic soils

Trace metal behaviour in volcanic ash soils displays distinctive features related to the soils’ large contents of metal‐binding phases and to the rapid release of trace metals from glasses and weatherable minerals. In this work, the BCR (Community Bureau of Reference) sequential extraction scheme (exchangeable + weak acid soluble, reducible, oxidizable, and non‐extractable metal fractions) was applied to selected COST‐622 European reference volcanic soils to determine partitioning of zinc and copper between various solid‐phase constituents, along with the major elements Al, Fe and Mn. The total extracted Al (ΣAl) was strongly correlated with acid ammonium oxalate extractable Al (Al_o) (ΣAl = 0.985Al_o+ 0.11, R²= 0.98), while the total extracted Fe clearly underestimated the amorphous fraction. Large values for the non‐extractable Al fraction were associated with the presence of gibbsite and phyllosilicates. Although the Zn and Cu contents of the soils were generally large, total amounts extracted (the potentially mobilizable fraction) were small, especially for Zn and for soils with crystalline secondary minerals. The fraction of the total Cu which was potentially mobilizable generally exceeded that of Zn. In the potentially mobilizable Cu the oxidizable fraction was generally dominant. Biocycling appears to play an important role in the surface enrichment of potentially mobilizable Zn and Mn. Although further methodological research seems necessary, the BCR sequential extraction appears to be a valuable tool for studies on metal dynamics in soils with andic properties.     

评估土壤微量元素生物有效性测定方法

Trace element-contaminated soils (TECSs) are one of the consequences of the past industrial development worldwide.Excessive exposure to trace elements (TEs) represents a permanent threat to ecosystems and humans worldwide owing to the capacity of metal(loid)s to cross the cell membranes of living organisms and of human epithelia,and their interference with cell metabolism.Quantification of TE bioavailability in soils is complicated due to the polyphasic and reactive nature of soil constituents.To unravel critical factors controlling soil TE bioavailability and to quantify the ecological toxicity of TECSs,TEs are pivotal for evaluating excessive exposure or deficiencies and controlling the ecological risks.While current knowledge on TE bioavailability and related cumulative consequences is growing,the lack of an integrated use of this concept still hinders its utilization for a more holistic view of ecosystem vulnerability and risks for human health.Bioavailability is not generally included in models for decision making in the appraisal of TECS remediation options.In this review we describe the methods for determining the TE bioavailability and technological developments,gaps in current knowledge,and research needed to better understand how TE bioavailability can be controlled by sustainable TECS management altering key chemical properties,which would allow policy decisions for environmental protection and risk management.     

An analysis of the potential of precision farming in Northern Europe

Abstract. Precision farming is the process of adjusting husbandry practices within a field according to measured spatial variability. In this review, we explore the prospects for precision farming using the principles that underly conventional soil management and agronomy. The cost-effectiveness of precision farming is determined by the cost of defining zones within fields, the stability of zones through time, the difference in treatment between zones in terms of cost, and the responsiveness of the crop in terms of yield and quality to changes in treatment. Cost-effective precision farming is most likely where prior knowledge indicates large heterogeneity and where treatment zones can be predicted, for example from soil type or field history. Soil related factors are likely to provide the main basis for precision farming because they tend to be stable through time and influence crop performance. In particular, soil mapping may usefully indicate the moisture available for crop growth, organic matter maps may be utilized for precision application of fertilizers and soil acting herbicides, and variation in soil pH can be mapped and used as a basis for variable lime application. However, comprehensive nutrient mapping is less likely to be economic with existing techniques of chemical analysis. The value of yield mapping lies in identifying zones which are sufficiently stable to be of use in determining future practices. Maps of grain quality and nutrient content would significantly augment the value of yield maps in guiding marketing decisions and future agronomy. Interactions between soil differences and seasonal weather are large, so yield maps show considerable differences from season to season. Interpretation of such maps needs to follow a careful, informed, analytical process. Extensive and thorough field experimentation by crop scientists over many years has shown that yield variation arises as a result of a large and complex range of factors. It is highly improbable that simple explanations will be appropriate for much in-field yield variation. However, the capacity to sense yield variability within fields as opposed to between fields, where there are many confounding differences, provides an opportunity for the industry to improve its understanding of soil-based effects on crop performance. This should support its decision taking, whether through precision farming or through field-by-field agronomy. The main obstacle to the adoption of precision farming is the lack of appropriate sensors. Optimal sensor configurations that will measure the specific needs identified by end-users need to be developed. The conclusions reached in this paper probably apply to farming throughout northern Europe.     

Background levels of trace and ultra-trace elements in soils of Japan

Five hundred and fourteen soil samples collected from 78 sites in Japan were analyzed for their contents of trace and ultra-trace elements. We estimated the background levels (natural abundance) of 57 elements in soils. The concentration ranges were so wide that the ratios of the highest values to the lowest values were more than 100 for all the elements, with the exception of Be, Ga, Mo, Ag, In, Sn, and Ba. While the concentrations of the first transition elements (₂₁Sc to ₃₀Zn in atomic numbers) were higher than the concentration of the other elements, those of lighter (₃Li and ₄Be) and heavier elements tended to decrease, with an increase or decrease of atomic numbers, with the apparent exception of Pb, Th, and U. Concentrations of elements with even atomic numbers were, in most of the cases, higher than the concentrations of both adjacent elements with odd atomic numbers. Frequency distribution of most of the elements was strongly positively skewed. Markedly positive correlation coefficients (r>0.9) were observed among the elements within the same group in the Periodic Table in many combinations. The dendrogram obtained by cluster analysis showed that the occurrence and distribution of the elements in soils were mostly controlled by the chemical properties of each element, rather than by the nature and properties of individual soil samples. The total contents of the elements in soils were strongly dependent on the chemical composition of the parent rocks from which respective soils were derived.     

The use of iron chelates in compound fertilizers containing trace elements

Abstract

The chemical behaviour of iron chelates, incorporated in compound fertilizers with inorganic micronutrient compounds, was studied. Pot experiments were conducted to evaluate the effectiveness of these products in controlling iron deficiency. A commercial compound fertilizer, containing 0.09% Fe as Fe‐DTPA, 0.12% Cu, 0.16% Mn and 0.04% Zn as sulfates, proved to be ineffective in preventing iron chlorosis in Chamaecyparis lawsoniana ’Alumii’, growing on sphagnum peat at two lime levels. The same fertilizer formulation with 0.09%‐ Fe as Fe‐EDDHA did prevent iron chlorosis at both lime levels. Fe‐EDTA, incorporated in the compound fertilizer, gave good results at the lower but not at the higher lime level, due to the low stability of Fe‐EDTA at high pH. Data from laboratory experiments showed that copper replaced the chelated iron in the compound fertilizer containing Fe‐DTPA, causing the iron to precipitate. The strong competition between copper and iron for the organic ligand is due to a specific affinity of copper for DTPA, resulting in a copper chelate with high stability constant and a molar ratio of copper to chelating agent of 2 : 1.

In the case of Fe‐EDDHA and Fe‐EDTA the competition between iron and copper is much weaker. In contrast to Fe‐DTPA, these chelates remain rather stable when incorporated in fertilizers containing micronutrients.     

华中黄棕壤和黄褐土粘粒胶膜的微量元素地球化学特征

The relationships between the basic properties and trace elementsin soil argillans and corresponding matrix soils were studied by sampling from the B horizons of 26 Alfisols in croplands of the subtropical area in Central China. The soil elements (K, Na, Ca, Mg, Mn, Co, Cu, Cr, Cd, Li, Mo, Ni, Pb, Ti, V, and Zn) were extracted by acid digestion and their contents were measured using inductively coupled plasma optical emission spectrometry (ICP-OES). The mean contents of clay and organic matter in the argillans were approximately 1.1 and 1.3 times greater than those in the matrix soils, respectively. The pH values and the contents of P₂O₅ and bases (K₂O, Na₂O, CaO, and MgO) in the argillans were higher than those in the corresponding matrix soils. Cu, Cd, Ti, and V were enriched in the argillans. Correlation coefficients and factor analyses showed that Co, Cu, Li, and Zn were bound with phyllosilicates and manganese oxides (Mn-oxides) in the argillans. Cr and Pb were mainly associated with iron oxides (Fe-oxides), while Ni was bound with Mn-oxides. Cd, Ti, and V were chiefly associated with phyllosilicates, but Cr and Mo were rarely enriched in the argillans. In contrast, in the matrix soils, Co and Zn were associated with organic matter and Fe-oxides, Cr existed in phyllosilicates, and Mo was bound to Fe-oxides. Cd, Ti, and V were associated with organic matter. The results of this study suggest that clays, organic matter, and minerals in the argillans dominate the illuviation of trace elements in Alfisols. Argillans might be the active interfaces of elemental exchange and nutrient supply in cropland soils in Central China.     

Manganese relationships in spring wheat and spring barley production in Northern Idaho

Abstract

Manganese is often limiting in cereal crop production in the Kootenai River Valley of Northern Idaho; however, attempts to relate DTPA‐extractable Mn in soils to crop yield response have not been successful. Consequently, Mn plant tissue diagnosis may be an alternate diagnostic tool. The objectives of this study were to: (1) determine the critical nutrient concentration (CNC) of Mn in spring wheat and spring barley tissue in the Kootenai River Valley of northern Idaho, (2) examine yield response of spring wheat and spring barley to Mn fertilization, and (3) assess relative efficiencies of foliar and surface broadcast Mn applications to these crops. Paired plots with four replications consisting of a foliar Mn application rate of 1.5 kg ha^‐1 and a control were located at four sites in 1988 and at ten sites in 1989. Soil, plant tissue samples and grain yield data were evaluated by linear plateau regression to determine CNCs of Mn for spring wheat and spring barley tissue. In addition, five randomized complete block experiments were conducted in 1989 and 1990 to evaluate Mn fertilizer rates and sources (foliar vs. surface applied) on spring wheat and spring barley production. Tissue Mn was highly correlated by linear plateau regression to both spring wheat (r² = 0.74**) and spring barley (r² = 0.70**) grain yield. The Mn CNC was established at 11.0 mg Mn kg‐¹ plant tissue for spring wheat and 10.1 mg Mn kg^‐1 plant tissue for spring barley. The Mn CNCs were established at 92.4 and 93.0% of maximum yield for spring wheat and spring barley, respectively. DTPA‐extractable Mn was not significantly correlated to grain yield for either crop (r² = 0.02, NS). Based on study results, Mn analysis of spring wheat and spring barley plant tissue was diagnostic of eventual grain yield. When tissue diagnosis showed plants to be deficient in Mn, the deficiency was corrected by applying Mn fertilizer as a surface broadcast or a foliar spray. However, foliar application of Mn was more efficient than broadcast application.