山核桃品质对产地土壤养分的空间响应

【目的】研究山核桃品质与对应产地土壤养分含量的相关性,了解土壤中养分元素含量对山核桃品质的影响,为山核桃合理布局和科学管理提供依据。【方法】以典型产区临安为研究区域,采集了153个山核桃样品及其对应土壤样品,采用地统计学方法和GIS空间分析技术,分析山核桃品质与产地土壤养分含量状况,探究山核桃及其产地土壤中大量及微量元素的空间分布特征和变异规律以及空间对应关系。【结果】相关系数结合交叉相关函数分析,发现土壤中各养分元素与果实品质元素之间均存在不同程度相关关系,其中果实氮与土壤碱解氮、有效磷、速效钾、有效锌、有效锰的相关关系较强;磷与土壤有效磷、有效硼、有效锰、有效锌的相关关系较强;钾与土壤速效钾、有效硼、有效铁、有效锌的相关关系较强;粗脂肪与土壤有效磷、有效硼、有效锌的相关关系较强。空间分析结果显示,临安各乡镇土壤大量及微量元素含量空间异质性明显,而山核桃果实中钾和粗脂肪空间异质性不明显,氮、磷的空间变异性明显,大致呈现西北地区低东南地区高的分布趋势。【结论】山核桃品质受土壤中磷、硼、锌三种元素影响较大。山核桃与土壤相应养分元素的空间分布格局具有一定相似性,尤其是高低值区域。岛石镇西部和南部、湍口镇、河桥镇、太阳镇及昌化镇南部的土壤养分元素和山核桃品质元素含量相对较高,昌化镇北部、清凉峰镇西部、龙岗镇北部的土壤养分元素和山核桃品质元素含量相对较低。     

茶叶与产地环境中稳定同位素和矿物元素特征及其相关性研究

为探究茶叶与茶园土壤、灌溉水源等产地环境中稳定同位素和矿物元素特征及其相关性,采用元素分析同位素质谱联用仪(EA-IRMS)和电感耦合等离子体质谱仪(ICP-MS)对山东日照和崂山的茶叶、栽培土壤及灌溉水源中4种稳定同位素比率(δ¹³C、δ¹⁵N、δD和δ¹⁸O)和23种矿物元素含量(Na、Mg、Al、K、Ca和Sr等)进行测定。结果显示,两地区中稳定同位素和矿物元素具有区域性特征,通过对茶叶中4种稳定同位素与栽培土壤(δ¹³C和δ¹⁵N)、灌溉水源(δD和δ¹⁸O)分别进行线性相关分析,结果表明,茶叶与栽培土壤中的δ¹⁵N相关性最大,R²为0.450 7,其次分别为栽培土壤中的δ¹³C(R²=0.289 5)、灌溉水源中的δ¹⁸O(R²=0.156 2)和δD(R²=0.021 4);同时,利用热图技术对茶叶与栽培土壤、灌溉水源中稳定同位素和矿物元素进行差异性及多重相关性分析,结果表明,茶叶与栽培土壤中δ¹³C呈较强负相关,而与灌溉水源中δ¹⁸O则无明显相关性。同时茶叶与栽培土壤中矿物元素也存在一定差异性,而茶叶中Cd、Li、Co、Sr、Mo与栽培土壤中相应矿物元素相关性较大。本研究初步揭示了稳定同位素在茶叶与栽培土壤、灌溉水源间的分馏情况以及与矿物元素的相关性,对研究农产品与环境因素间同位素分馏和元素累积规律具有一定的参考价值。     

伊犁河流域土壤重金属含量空间分布及其环境现状研究

以新疆伊犁河流域地区作为研究区域,在对研究区域典型土壤样品中重金属元素Cu、Pb、As、Hg的含量分析基础上,运用GIS地统计学知识分析研究区域土壤Cu、Pb、As、Hg含量的空间分布特征.结果显示:土壤中Cu、Pb、As含量都明显高于新疆土壤背景值,而Hg含量则是显著低于新疆土壤背景值,各元素在研究区域土壤中均表现出不同程度的变异性,其中土壤中As含量的变异程度最大;通过空间分析发现,土壤中Cu、As、Hg含量均表现出中等程度空间相关性,其空间分布受随机因子和结构因子的双重影响,其中土壤As含量受随机因子的影响最大,而土壤Pb含量表现出强烈的空间相关性,主要受结构因子影响.采用内梅罗指数评价法对土壤Cu、Pb、As、Hg含量进行环境污染评价,评价结果显示,土壤Hg尚未受到污染;土壤Cu、Pb属于中度污染,局部地区属于轻度污染;土壤As属于重度污染,其中霍城县、伊宁县、伊宁市、察布查尔县污染现象极为严重.     

基于多元统计和地统计的肇源县表层土壤重金属来源辨析

土壤圈是地圈系统中对人类健康影响最显著的圈层之一。土壤重金属的自然和人为来源辨析对土壤修复和保障人体健康有重要意义。本研究以黑龙江省肇源县为研究区域,通过空间插值分析、主成分分析和聚类分析等方法,对区域土壤表层和深层土壤重金属As、Hg、Cd、Cr、Cu、Ni、Zn的含量和空间分异特征进行分析,进而对区域表层土壤重金属来源进行辨析。结果表明:成土母质作为表层土壤的重要物质来源对表层土壤重金属含量及空间分布有显著影响;肇源县表层土壤中Hg元素表现出全局范围较明显的富集现象,局部区域Cd元素表现出一定的富集现象,富集原因是人为污染造成的;嫩江上游汇水区土壤重金属元素的迁入,是表层土壤重金属As、Cd、Cr、Cu、Ni、Zn等元素在研究区范围内轻度富集的主要原因。     

土壤可见光-近红外反射光谱与重金属含量之间的相关性

发展基于反射光谱技术的快速、简便、低成本的土壤重金属信息提取方法是区域土壤重金属污染治理所需要的。选择江西贵溪铜冶炼厂污染区,分析了9种重金属元素(Cu、Pb、Zn、Cd、Co、Ni、Fe、Mn及Cr)与土壤可见光-近红外反射光谱之间的相关性及其相关的原因。研究表明,研究区土壤中存在Cu(含量介于66.71~387 mg kg-1之间)和Cd(含量介于0.36~6.019 mg kg-1之间)的强烈富集。土壤重金属含量与反射光谱之间存在显著相关,污染元素Cu的最高相关系数为-0.87,Pb、Zn、Co、Ni、Fe的最高相关系数达到高度相关(|r|>0.80),Cr、Cd、Mn的最高相关系数达到显著相关(|r|>0.70)。微分光谱适于获取土壤中的重金属元素信息,利用组合波段能显著提高相关性。Cu与反射光谱之间的相关性主要受有机质的影响;Pb、Zn、Co、Ni主要受黏土矿物和铁锰氧化物的影响;Cr与反射光谱之间的相关性同时受有机质和黏土矿物的影响。     

恩施典型富硒区土壤硒与其他元素组合特征及来源分析

硒是重要的人体和动物必需微量元素之一,在功能农业发展中起着重要的作用。为了研究高硒土壤中硒与其他元素组合特征及来源,从而支撑富硒资源的安全有效利用,本研究在恩施市沙地乡系统采集并分析了200个表层土壤样和2组土壤垂向剖面样品,运用统计学工具进行了聚类分析和因子分析。结果表明:研究区表层土壤硒含量平均值为1.88 mg/kg±2.51 mg/kg,明显高于全国表层土壤硒含量平均值。研究区土壤元素组合特征可分为三类,第一类中硒与钼、钒、铬、镉和镍等元素具有较强的伴生关系,与黑色岩系分布密切相关;第二类为三氧化二铝、铅和砷等元素/氧化物,与土壤中黏土矿物有关;第三类为钙和锶等元素,表明该同族元素的地球化学性质具有相似性。因子分析结果进一步证实了土壤硒和镉伴生主要发生在黑色岩系,不同成土母质硒等元素差异较大。     

新疆准东矿区土壤与降尘重金属空间分布及关联性分析

土壤重金属与大气降尘重金属之间的关联性可以反映重金属污染的来源、土壤-大气系统中重金属的传输、迁移和扩散特征。为了研究矿区表层土壤的污染状况及与降尘重金属质量分数间的关联性,该研究以新疆维吾尔自治区准东矿区为研究靶区,利用2014年采集的51个表层土壤和大气降尘样品的室内实测重金属质量分数数据,并基于此分析了样品中6种重金属(As、Cu、Cr、Hg、Pb、Zn)的空间分布特征、地积累指数以及潜在生态风险;利用Pearson相关性分析矩阵和灰色关联法对表层土壤与大气降尘中重金属浓度的相关性和关联度进行探讨。结果表明:1)准东矿区表层土壤重金属的分布状况存在着明显的空间差异,其中Hg的污染程度最严重,处于强-极强度污染,其潜在生态危害指数达到了较高生态风险;Zn和Cu基本处于无污染状态,属于轻微生态风险;2)大气降尘重金属空间分布存在着明显差异,降尘中的Zn处于极强度污染,Hg处于无污染状态;3)Pearson相关分析与灰色关联分析表明,准东地区表层土壤与大气降尘中6种重金属的相关系数大小顺序与关联度排序结果一致,其中Hg和As元素具有较强的一致性,且具有相同的来源,说明大气降尘对表层土壤中重金属的质量分数有一定影响。但因不同重金属元素沉降特性不同,导致各元素之间的关联度有所差异。     

怀涿葡萄产区土壤过氧化氢酶活性空间分布规律及影响因素分析

为了探明影响土壤过氧化氢酶活性空间变异规律的葡萄品种、土壤物理、化学因素及其内在关系,本文利用GIS和地统计学分析方法研究了怀涿葡萄产区(河北省怀来、涿鹿两县)的83个表层土壤样品。结果表明:怀涿葡萄产区表层土壤过氧化氢酶活性表现出较强烈的空间相关性,其变异规律呈现出明显的区域差异分布特征,土壤过氧化氢酶活性的最佳空间拟合模型为指数模型;土壤中大量元素(除K外)、中量元素、微量元素、重金属元素和一些有益元素(V、I)均对土壤过氧化氢酶活性表现出了显著或极显著的活化作用。在当地传统的土壤葡萄体系管理模式下,土壤过氧化氢酶活性的空间变化规律与土壤不同空间位点的大多数化学元素含量变异分布特点密切相关;土壤过氧化氢酶活性与细粉粒含量呈显著正相关,与土壤黏粒含量呈极显著正相关,可以认为物理性黏粒尤其是黏粒和细粉粒含量是影响怀涿葡萄产区表层土壤过氧化氢酶活性空间变异特征的另一个重要因素。而葡萄品种和土壤pH对土壤过氧化氢酶活性影响较小,与土壤过氧化氢酶活性的空间分布规律关系不大。     

白洋淀内不同土地利用类型土壤重金属分布特征与污染评价

  目的  白洋淀作为雄安新区生态共同体的重要组成部分,在“白洋淀生态环境治理和保护规划”中,淀区内陆地将被淹没。为科学评价淹没后陆地对白洋淀水体的环境影响,从淀区不同土地利用类型土壤重金属元素分布特征及污染程度评价两个方面开展了研究工作。  方法  以淀区内现有陆地0 ~ 20 cm土壤为研究对象,以砷、汞、镉、铬、铅、镍、铜、锌重金属元素为研究要素,以统计分析、污染负荷指数法和地质累计指数法评价为分析手段,对淀区内陆面重金属元素统计特征和污染程度进行分析和评价。  结果  淀区内陆地土壤重金属元素背景值显著高出区域背景值,污染程度总体为轻度污染;农业用地类型土壤重金属污染元素最多, 铜、镉、汞是本区陆地土壤中背景值高、污染贡献最为显著的元素。  结论  淀内陆地土壤重金属元素含量均低于国家标准（GB 15618—2018）和（GB 36600—2018）中土壤筛选或管控的标准,环境承载力仍有一定缓冲容量;重金属元素间的相关性特征主要由地质背景因素控制,但也明显受到土地利用类型改变的影响。     

夏尔希里地区土壤磁化率、重金属特征及相关性分析

现今环境学研究的热点问题之一是探讨土壤地磁特征与重金属的耦合关系。为了探明夏尔希里地区土壤磁化率与重金属的特征,以及它们之间的相关性,本文选取夏尔希里地区的67个土壤剖面进行磁化率、重金属含量的测定,通过统计分析,研究表明:1低频磁化率的特征为:除了绿洲的土壤低频磁化率与土壤深度关系不明确外;山地和荒漠都是随土层深度的增加,低频磁化率值递减。此外,新疆土壤的频率磁化率值都较低。2山地土壤类型重金属元素含量排序为MnZnPbCrCuAsNiCoHg;绿洲土壤类型重金属元素含量排序为MnZnAsCrPbCuNiCoHg;荒漠土壤类型重金属元素含量排序为MnZnCrAsPbCuNiCoHg。3通过对夏尔希里地区土壤磁化率、重金属特征及相关性分析得出:研究区土壤类型不同土层中,山地低频磁化率与土壤深度的相关性显著,重金属之间相关性显著。上述分析可以对区域环境的治理及保护提供科学参考。     

湖南张家界典型植烟土壤地球化学特征研究

为了研究张家界山地植烟区域土壤的成土环境及地球化学元素的丰缺状况和迁移富集规律,为烟区优质特色烟叶的生产和布局提供科学依据,本文采集23个长期耕种的典型植烟土壤剖面样品,测定分析了25种地球化学元素(氧化物)的含量,并对土壤的风化发育状况和元素(氧化物)的迁移富集特征进行了研究。结果表明,张家界烟区主要成土母质如石灰岩、板页岩、紫色砂页岩风化物均受到了较强的风化作用,化学风化指数(CIA)介于73.19～88.03之间,总体上土壤具有Ca、Na贫乏而Fe、Al相对富集的化学组成特征。其中紫色砂页岩风化物发育形成的紫色土的风化作用较强,土壤的淋溶作用较强;石灰岩风化物发育形成的土壤富铝化程度较低。黄壤、水稻土、紫色土中地球化学元素多数表现出一定的富集特征,大量有益营养元素的富集对于提高烟叶产量具有重要作用。土壤剖面淋溶层中元素(氧化物)P、B、Se、Mn、Zn、Cu、Ni、Y、Sc、La、Fe2O3、SiO2的含量均高于中国或世界土壤元素(氧化物)中值(均值),而N、S、Cl、Mo、Co、Sr、Br、I、CaO、MgO、K2O、Na2O、Al2O3的含量偏低,其中元素(氧化物)N、P、S、Mo、Se、Mn、Zn、Br、I、CaO、MgO在土壤剖面中的含量变化较大。通过对元素(氧化物)富集系数的聚类分析,将元素(氧化物)分为3类:呈较强富集特征的元素N、P、S、Se;呈较强迁移特征的元素(氧化物)Br、I、Mn、CaO;变化较稳定的其他元素。微量元素B、Zn、Cu和稀土元素Y、Sc、La含量较丰富且变化相对稳定,表明除了常量元素N、P、S以外,微量元素Se、B、Zn、Cu和稀土元素Y、Sc、La可能是影响张家界烟区烤烟品质的重要特征元素。     

Incinerated Sewage Sludge Products as Amendments for Agricultural Soils: Leaching and Plant Uptake of Trace Elements

Preliminary leaching column and greenhouse plant uptake studies were conducted in two soils with contrasting characteristics amended with varying rates (0 to 148.3 Mg ha^?1) of incinerated sewage sludge (ISS) and weathered sewage sludge (WISS) to estimate the leaching losses of trace elements from the soils amended with incinerated sewage sludge by products and to evaluate the uptake and accumulation of these elements in various parts of Sorghum vulgaris var. sudanense Hitche. (“Sorgrass''), a Sorghum-Sudan grass hybrid. Results of this study indicated that leaching of Cr, Cd, Zn, Cu, Ni, Fe and Mn from soils amended with ISS and WISS increased with increasing rates of amendment. Results of the leaching column study further revealed greater leaching losses from coarse-textured soil compared to medium-textured soil and also from ISS amended soils than with WISS amended soils. Results further suggested that the type of element and the interaction between the element and soil properties affected the leachability of various trace elements. The uptake study indicated uptake and accumulation of trace elements by plant parts increased with increasing rates of amendments. Greater plant uptake and accumulation of trace elements were observed in plant parts grown in soils amended with ISS compared to that of WISS. Results also indicated a greater accumulation of trace elements in below ground part of the plants (roots) compared to that was observed in above ground parts (shoots). Limited data obtained from this one season preliminary studies demonstrated that incinerated sewage sludge products from wastewater treatment plants could be used as soil amendments at low application (no more than 24.7 Mg ha^?1) for optimum plant growth, and dry matter yield without resulting in substantial accumulation of metals in plant parts at concentrations above the recommended critical limits and without causing significant leaching losses of various trace elements. It is imperative that long-term field studies are necessary to evaluate the long-term impact of using these new products in leaching and accumulation of various trace elements in plants and soils.     

Defining soil geochemical baselines at small scales using geochemical common factors and soil organic matter as normalizers

Purpose

The establishment of geochemical baselines is essential for accurate evaluation of the present state of surface environments. In this study, normalization procedures (NP), which can improve the explanation of the natural variation of elements, were conducted using geochemical common factors (GCF) and soil organic matter (SOM) as normalizers to define the geochemical baselines of soil trace elements.

Materials and methods

Soil samples (n?=?345) were collected in Luhe County, Jiangsu, China, a county with a complex geologic setting and intensive anthropogenic influence. Conservative elements, Al, Ca, Fe, K, Mg, Mn, Na, P, and Ti; trace elements, As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn; and SOM were measured. Normalization procedures were conducted using multiple linear regressions between soil trace elements and SOM and GCFs, acquired from factor analysis of the soil major elements. Normalization procedures using univariate linear regressions between soil trace elements and conservative elements Al, Fe, and Ti were also conducted for comparison.

Results and discussion

Comparison of NPs using GCFs and SOM as normalizers with NPs, which use single conservative elements as normalizers, shows that the former is more accurate than the latter for As, Pb, and Zn and is as accurate for Cd, Cr, Cu, Hg, and Ni, when the most appropriate single conservative element is chosen. Small-scale geochemical baselines in the county are significantly different from regional-scale geochemical baselines for Jiangsu Province, China.

Conclusions

The application of regional-scale geochemical baselines at small scales may lead to estimation errors in determining anomalies and assessing environments. Baselines obtained from the NPs using GCFs and SOM as normalizers are more accurate.     

同位素稀释技术在土壤微量元素地球化学活性分析中的应用

土壤中微量元素的地球化学活性是评价土壤质量以及环境风险的重要指标.现有的分析方法虽多,但因技术限制难以适用于所有类型的土壤,致使标准不统一,对科研工作提供的参考性不足.同位素稀释技术(isotopic dilution technique)对固/液交换过程造成的扰动极小,近年来被越来越多的研究人员认为是量化土壤微量元素...     

Antimony Accumulation in Wheat Seedlings Grown in Soil and Water

The purposes of the research were (1) to estimate the ability of wheat Triticum aestivum L. to uptake antimony (Sb) from contaminated soil and water, (2) to study effects of Sb bioaccumulation on the plant development and distribution of macro- and trace elements in the plants, and (3) to compare uptake of Sb and some other elements by wheat seedlings grown in solid (soil) and liquid (water) media. Both soil-grown and water-grown plants were capable of accumulating large amounts of Sb. In roots, concentration of Sb was always greater than in leaves, suggesting that roots can prevent transfer of the trace element to upper plant parts. Uptake of Sb by the plants grown in water was significantly greater compared to Sb uptake by the plants grown in soil. Antimony bioaccumulation resulted in variations in concentrations of some nutrients in different plant parts and decrease of the seedling biomass.     

The influence of brine contamination and phospho‐gypsum amendments on soil chemical properties and plant response

Abstract

Phosphogypsum (PG), the by‐product of wet acid production of phosphoric acid from rock phosphate, was found to be effective as a soil conditioner for sodic, solonets, and solonetzic soils. Unlike mine gypsum, PG contains impurities whose release into soil and ground water need to be monitored. PG was incorporated with soils contaminated with oilfield brine to determinate the influence of PG amendments and brine contamination on soil chemical properties and plant response in a growth chamber. Application rates of PG were 0, 25, 50, 100, 200, and 400 Mg ha^‐1 and the testing crop was Barley (Hardeum vulgare L.). Phosphogypsum provides a means of remediating brine spills and can result in benefits expressed as increased plant growth. Soil salinity of brine contaminated soils was ameliorated as evidenced by reduced the electrical conductivity, SAR and exchangeable Na levels in 0–15 cm depth of the columns. There is no evidence that application of PG increased the level of trace elements in plants. Contamination of soil with brine spill is the major factor dominating plant growth and soil‐plant element content. From plant growth point of view, two elements could be excessive, namely Boron (B), and Cadmium (Cd). The high level of B in the plant arose from brine spill and the cause for the excessive Cd level in barley grain is unknown and currently under investigation. The distribution of trace elements in soil profiles demonstrated that there was little, if any, potential for movement of trace elements into greater depths.     

贵州喀斯特地区草地开垦对土壤微量元素的影响与评价

为探明生态脆弱区土地利用方式转换对土壤有效态微量元素的影响,以贵州喀斯特地区草地及其相应开垦的农田为对象,采用成对设计的方法研究了草地开垦对土壤微量元素（铜、锰、铁、钼、硼、锌）的影响,并探索基于土壤微量元素密度的区域土壤微量元素丰缺评价指标。结果表明：研究区土壤有效态微量元素在土壤剖面上呈表面富集现象,其含量随土层深度的增加而降低;草地开垦导致土壤有效态铜、铁、硼和钼的含量出现不同程度的降低,降幅为4.97%～79.17%,而土壤有效锌含量则增加,增幅为11.76%～46.06%;开垦导致土壤有效锰含量在剖面上的下降速率加快。建立了研究区6种有效微量元素的丰缺评价指标,该指标以土壤微量元素密度为参数,以参数值的不同范围界定微量元素的丰缺程度,消除了微量元素空间异质性对判定结果的影响。根据该评价指标,研究区土壤有效铁、锰处于极高水平,草地开垦导致土壤有效铜、钼、硼的丰度下降,而有效锌的丰度上升;结合微量元素有效性评价指数,整个研究区土壤有效硼处于低水平,不能够满足植物正常生长发育的需要。该研究结果可为生态脆弱区土地的科学管理和土壤微量元素科学评价体系的建立提供参考。     

Bioaccumulation of mineral elements in grapevine varieties cultivated in “La Mancha”

The capacity of a plant to take up chemical elements is measured as the ratio of the element concentration in the plant and its concentration in the soil. This ratio is called the bioaccumulation index (BAC). The choice of rootstock and variety can differentially affect nutrient uptake of grapevine (Vitis vinifera L.). Generally, only slight differences can be observed in the accumulation of N, P, and Zn. In contrast, wide variations are found in the absorption of K, Ca, Mg, and Cl. While studies on plant nutrients and major elements have been carried out in vineyards, very few references concern the trace‐element concentrations in leaves. In the study described here, five varieties (Airén, Cencibel, Garnacha, Cabernet Sauvignon, and Chardonnay) grown on a Calcisol Petric or Typic Calcixerept (typical of La Mancha) were compared in terms of leaf trace‐element concentrations. A total of three samples (20 healthy and completely developed leaves from the middle part of the shoot) were collected from three different plants of the same variety. Leaves were dried, milled, and x‐ray fluorescence analysis was performed. It was found that the variety of grapevine influences the uptake of four of the major elements: Al (low in Garnacha, [0.4 ± 0.2] g kg^–1), Ca (high in Cencibel, [32.6 ± 8.1] g kg^–1), P (low in Airén, [0.9 ± 0.4] g kg^–1) and K, which showed significant differences in almost all of the varieties (from [4.7 ± 1.8] g kg^–1 in Cencibel to [8.0 ± 10.1] g kg^–1 in Chardonnay). No statistically significant varietal differences were found for trace elements. The only exception was La, which was present at higher levels in the variety Cencibel ([7.5 ± 0.3] mg kg^–1). This finding allows to assess the geochemical fingerprinting of calcareous soils regardless of the grapevine variety studied.     

Soil pollution by mining activities in Andalusia (South Spain)—the role of Mineralogy and Geochemistry in three case studies

Purpose

Geochemical and mineralogical studies of soils potentially polluted by trace elements are basic to find the source of pollution, to understand the behavior of the contaminants in the environment, and to propose remediation and reclamation actions. This work reviews the role of the Mineralogy and Geochemistry to assess the hazard of soil contamination by trace elements in mining areas, focusing on three different case studies carried out in the Andalusian community (South Spain), with a Mediterranean temperate climate.

Materials and methods

Two significant mining districts were selected for this work: the Linares-La Carolina (Pb-Zn ores) and the Riotinto (Iberian Pyrite Belt, IPB) mining areas. Another case study was the Guadiamar basin, which soil was polluted by the spill produced in 1998 by the breakage of a mine tailing impoundment in Aznalcóllar mines (IPB). Soils, mine waste, and secondary precipitates were studied to approach the source of the pollution and the fate of the contaminants. Chemical composition (major and trace elements), soil parameters, and mineralogy of all materials selected were studied. In addition, the bioavailability of trace elements was determined by different methods.

Results and discussion

Pyrite and secondary phases are the main sources of pollution in the Riotinto area. Their stability is a key factor in the release of trace elements. The availability of trace elements in soils was lower in unpolluted leptosols than in contaminated orchards. In Linares-La Carolina, a severe pollution by Pb and a high availability (10–70% extracted with EDTA) were found. In Guadiamar basin, the residual pyrite sludge continues releasing trace elements to soil. Cd and Zn were mobile at pH <?6 and As at pH >?8, and Pb was quite immobile. Cd, Zn, and Pb can be coprecipitated by carbonates while As is mainly adsorbed by clays and iron oxyhydroxides.

Conclusions

The geochemical studies of soils polluted by mining activities allow to evaluate the availability of trace elements and their retention in soils. Therefore, geochemical and mineralogical studies are necessary for the assessment of soil pollution and remediation actions.

     

农牧交错带草地开垦对土壤有效态微量元素的影响及评价

为明确草地利用方式转变对土壤微量元素的影响,以华北农牧交错带2种类型草地及其相应开垦的农田为对象,采用成对设计的方法研究了开垦对草地土壤表层(0～20cm)有效态微量元素(铜、铁、锰、锌、硼、钼)的影响并对其进行了评价,以期为农牧交错带的科学管理提供参考。结果表明:典型草地开垦导致土壤有效态铜、锌含量分别上升8.8%和16.4%,其他4种微量元素含量下降16.4%～28.1%。根据土壤有效态微量元素评价标准,典型草地区域有效态硼、钼含量处于高水平,有效态铜处于中等水平,有效态锌处于极低水平;有效态铁、锰在典型草地为高水平和中等水平,开垦为农田后分别降到中等水平和低水平。低湿草甸开垦导致微量元素含量下降10.6%～77.7%,其中有效态铁、硼、钼处于极高水平,有效态锰处于中等水平,有效态锌处于极低水平;有效态铜由低湿草甸的高水平降到农田的中等水平。整个研究区土壤有效锌含量限制草地植被和农作物生长发育,由典型草地开垦的农田其土壤有效锰含量不能够满足作物的需求。建议研究区禁止开垦草地并对已开垦的草地实行退耕还草,同时建议建立基于土壤微量元素密度的评价体系。