Estimation of Reference Values for Cadmium,Cobalt, Chromium,Copper, Nickel,Lead, and Zinc in Brazilian Soils

Abstract

The objectives of this study were 1) to recommend reference values (RVs) and tolerance limits (TLs) for representative Brazilian soils and 2) to propose a model to calculate natural contents of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in a soil from the silt, clay, manganese (Mn), iron (Fe), and cation exchange capacity (CEC) values. A set of 256 soil samples was classified by similarity in seven groups, and the concentrations corresponding to the upper quarter of data collected were then calculated. These concentrations are proposed as RVs for Brazilian soils. Additionally, TLs were obtained for each group from the antilog expression (m+2s), where m=mean value and s=standard deviation of data transformed in log₁₀. The classification functions of discriminant analysis proved to be suitable to allocate new samples in the established groups. Thus, it is possible to evaluate soils under anthropic activity and, by comparison with reference values, to be aware of pollution risks in a given area.     

Bioaccumulation and Distribution of Lead,Zinc, and Cadmium in Crops of Solanaceae Family

Comparative research has been carried out to determine the quantities and accumulation of lead (Pb), zinc (Zn), and cadmium (Cd) in the vegetative and reproductive organs of crops of the Solanaceae family (tomato, pepper, and aubergine) as well as to identify the possibilities of growing them on soils contaminated by heavy metals. The analyses were carried out by inductively coupled plasma–atomic emission spectrometry after dry ashing. Heavy metals have an impact on the development and productivity of the crops of the Solanaceae family. The high anthropogenic contamination impedes the normal development and fruit‐bearing ability of the pepper and aubergine plants, and in the case of tomatoes, it led to an increased assimilation of heavy metals without reducing the yield and the quality of the production of tomatoes. Crops from the Solanaceae family, tomato, pepper, and aubergine plants, could be cultivated on soils having low and medium levels of contamination of heavy metals, because they do not show a tendency to accumulating Pb, Zn, and Cd in their fruits, which could still be used for consumption.     

Organic carbon stocks and soil erodibility in Canary Islands Andosols

Soil organic carbon (SOC) plays a key role in the structural stability of soils and in their resistance against erosion. However, and as far as andic soils are concerned, these mechanisms and processes, as well as the influence of the different types of SOC on aggregate stability, are not fully understood. The targets of this paper are: (i) to determine the content and forms of SOC in Andosols under evergreen forest vegetation [laurel (Laurus) and heather (Erica) forest] and (ii) to find out the role of soil organic matter (SOM) in the aggregate stability and in the resistance of Andosols to water erosion. Soil samples have been collected in 80 sites in a 40 km² area under udic soil moisture regime. In them, fulvic and humic acids, Walkley–Black SOC, pyrophosphate-extractable SOC, Fe and Al, potassium sulphate extractable SOC, dissolved SOC, acid oxalate-extractable Fe, Al and Si, USLE K-factor and aggregate stability have been determined. The Andosols over volcanic ash are Aluandic Andosols (non-allophanic Andosols), whereas over basaltic lava flows are Silandic Andosols (allophanic Andosols). The surface (0–30 cm) samples analyzed contain 9.5–30 kg C m^− 2 being significantly higher in allophanic Andosols (p < 0.5). Organic carbon adsorbed onto the mineral fraction (extractable pyrophosphate, C_p) accounts for 35–55% of the total SOC. All samples show a high stability to slaking and raindrop impact, being the first one highly correlated (r = 0.6) with pyrophosphate extractable C (C_p), Fe (Fe_p), and Al (Al_p) in allophanic Andosols, unlike non-allophanic ones. The stability to raindrop impact correlates with pyrophosphate extractable C (C_p) and Fe (Fe_p) in both types of soils (r = 0.3–0.6, p < 0.05). These findings suggest that the high stability to both slaking and water-drop impact is due to the occurrence of allophane–Fe–OC complexes, rather than to the total OC, and the active Fe and Al forms, generated by the weathering of volcanic materials, constitute an essential constituent responsible for C sequestration and resistance to degradation in these soils.     

Evaluation of Cadmium,Copper, Lead,and Zinc Levels in Soil Samples near Locust Pods

The genus Prosopis is a tree or shrub in the leguminosae family, subfamily fabaceae (mimosaceae). Many plants of the genus Prosopis are known to have medicinal properties. Only one species of Prosopis is found in Jordan, Prosopis farcta (Banks & Sol.) J.F. Macbr. The local name is Yanbout, and the English name is locust pods.

The aim of this study was to investigate some selected heavy metals including cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in Prosopis farcta, an unexplored Jordanian species of the Prosopis genus, because no data are available about these levels in this medicinal plant. These metals were tested in different parts of Prosopis farcta including root, aerial, and fruit as ethanolic extract plant and dry plant. Moreover, these metals were investigated in soil samples collected from the same area in which Prosopis farcta was grown. Results revealed that there was a significant difference between root and fruit for all test elements (P < 0.05). Roots were found to contain high average concentrations of Pb (2.14 µg g^?1), Cu (18.56 µg g^?1), and Zn (13.74 µg g^?1). Copper and Zn concentrations in Prosopis farcta were within the permissible limits, whereas Pb concentration exceeded the permissible limit. Moreover, soil samples were analyzed for the metals. Results revealed that there was a positive correlation between the levels of Cu and Zn in medicinal plants and soils, whereas there was a negative correlation for Pb.

Two certified reference materials (tea leaves, NCSDC 73351; soil, GBW 07406) were analyzed to authenticate the accuracy of the method, and the precision was expressed by relative standard deviation.     

Aggregates stability and water erosion in Andosols of the Canary Islands

The aim of this paper is to assess the mechanisms of water erosion in andic soils using two tests, which in a certain way simulate the two principal mechanisms of aggregate destruction in the process of water erosion—water dispersion and raindrops impact—and compare them with the aggregation observed in material dettached by inter‐rill erosion (sediments) in experimental plots with natural rain. In accordance with the obtained results, the erosive process in these soils seems to come about through a picking off of surface material of larger aggregates, due to the impact of raindrops. The intensity of pull off and fragment size from larger aggregates depends on the kinetic energy of the drops (rain intensity), but the size generally ranges between 0ċ2 and 0ċ5 mm. Therefore inter‐rill erosion initially proceeds by a washing down of smaller aggregates (<0ċ5 mm) (of less bulk density than larger aggregates 0ċ4 Mg m⁻³ against 0ċ9 Mg m⁻³), enriching the soil in larger sized aggregates which, on being fragmented by picking off of raindrops, supply new material for washing down by inter‐rill erosion. Copyright © 2002 John Wiley & Sons, Ltd.     

Radiocesium transfer from Andosols to brown rice in the northern and northwest areas of Tochigi Prefecture,in the first 3 years following the 2011 Fukushima Daiichi nuclear power plant accident

ABSTRACT

Following the Fukushima Daiichi Nuclear Power Plant accident of 2011, the potential for radiocesium transfer from contaminated soils, such as Andosols, to agricultural crops became a significant concern. Andosols account for up to 70％ of paddy soils in the northern and northwest areas of Tochigi Prefecture, where the radiocesium concentration is 1000 Bq kg^?1 or greater in the soil of some fields. The present study was carried out in order to determine the phytoavailability of radiocesium in Andosols by comparing it with that of gray lowland soils in the first 3 years following the accident. The transfer factor (TF) tended to be higher in Andosols than in gray lowland soils, leading to higher radiocesium concentrations in brown rice grown in Andosols. The exchangeable potassium (Ex-K₂O) in Andosols was highly and negatively correlated with TF, followed by clay. The Ex-K₂O value was positively correlated with the clay/total carbon (T-C) value, suggesting that a high T–C ratio could weaken K₂O adsorption on clay mineral sites; hence, the low clay/T-C values can partially explain the relatively large TF values of Andosols. Samples with Ex-K₂O contents less than 200 mg kg^?1 and with low clay/T-C values showed striking decreases in TF values from 2011 to 2012. However, the decrease from 2012 to 2013 was quite small; radiocesium in these samples was potentially available for rice uptake for a long time, likely due to the reversible adsorption and fixation characteristics of allophane. Most gray lowland soil samples showed very low TF values over the 3 years of the study, except for those with TF values greater than 0.1 due to low Ex-K₂O and clay contents; the geometric mean (GM) value of TF was below 0.01 in 2012. The extraction of exchangeable radiocesium (Ex-Cs) with a 1 mol L^?1 ammonium acetate solution may not be an appropriate method for explaining the variability in radiocesium TF in Andosols. This is because the Ex-Cs value was significantly correlated with Ex-K₂O in Andosols, but not in gray lowland soils, indicating that Ex-K₂O explained this variability in relation to Ex-Cs.     

Heavy Metal and Arsenic Profiles in Ombrogenous Peat Cores from Four Differently Loaded Areas in Finland

The concentrations and vertical distribution of Cu, Ni, Zn, Pb and As were studied in four different ombrotrophic peat bogs with varying heavy metal loads at Hietajärvi, Outokumpu, Harjavalta and Alkkia in Finland. At each site a peat sample (15 cm × 15 cm × 100 cm) was taken using a Titanium Wardenaar corer, and the samples were cut into 5 cm slices. Dried and milled samples were determined by X-ray fluorescence (XRF). The mean concentrations of the elements were at their highest at Harjavalta (the most polluted area), apart from Cu which had the highest value at the Cu-treated site at Alkkia. Cu concentrations were above the lowest effective limit (LOEL) on all the plots except for the background plot at Hietajärvi. The maximum Cu values were reached in the topmost 20 cm layer, indicating the effects of mining and smelting activities. The highest Zn and Ni concentrations occurred in the 0–40 cm layer. At all sites, the maximum Pb concentrations were located between 10 and 50 cm. However, the Pb concentrations were higher at Alkkia and Harjavalta than at Outokumpu and Hietajärvi, indicating anthropogenic sources of Pb at the former sites. The As concentration was also the highest in the uppermost peat layers. The mean concentrations were markedly lower in the deeper layers (40–80 cm) than in the upper layers.     

Andosols and soils with andic properties in the German soil taxonomy

The presence of soils with andic properties on German territory has been suspected for decades and there are numerous reports of sites where they may potentially occur. Andic properties, however, are not adequately represented by the German soil‐classification system. The German taxonomic category “Lockerbraunerde” has not been revised or reconciled with international taxonomic categories since the year 1957, when it was initially proposed. With this review, we show that there are true Andosols of both the silandic (allophane‐containing) and the aluandic (Al‐Humus‐dominated) type in Germany and that their properties differ substantially from other soils which merely exhibit low bulk density. By (1) comparing soil carbon storage between some German Andosols, Chernozems, and nonandic Cambisols with particularly low bulk density and (2) elucidation of the differential pedogenetic pathways leading to Andosol formation, we further demonstrate that Andosols are important objects of study in research issues of contemporary interest. We propose that appropriate measures be taken to lay the foundations for the protection and conservation of these soils, because they are valuable as archives of natural history and provide opportunities to study unique soil processes.     

Effect of phosphogypsum application on the chemical properties of Andosols,and the growth and Ca uptake of melon seedlings

Abstract

Allophanic Andosols are widely used as a major material in commercial nursery media for fruit vegetables in Japan because of their remarkable physical properties, such as a high water-holding capacity. In the present study, our objectives were: (1) to examine the effect of phosphogypsum (PG) on the chemical properties of Andosols, (2) to investigate the effect of PG on the growth and Ca uptake of melon seedlings. The effect of PG on chemical properties of Andosols was studied using five Andosols with different inorganic and organic colloidal components. The change in soil pH (H₂O) was dependent on the soil samples; an increase was observed in the case of Kawatabi 3Bw soil; a sharp decrease in Kawatabi A2 soil; and almost no change or a slight decrease in Kameoka A1, A2 and Bw soils. The water-soluble Ca content was examined as an index of Ca availability in Andosols treated with PG. The increment in water-soluble Ca by PG application was depressed by allophane. The effect of PG application to the nursery media prepared from Andosols on growth and Ca uptake of melon (Cucumis melo L.) was examined in 2002. Three different varieties, Amusu, Earl's and Midorishima, were used in this experiment. The pH value of nursery media was stable at 6.4 ± 0.1 regardless of PG application rate. In contrast, electrical conductivity was clearly increased by PG application, and was reached at 1.2 dS m^?1 in 4.0 g L^?1 application. The application of PG increased water soluble Ca of nursery media from 1.7 to 5.2 cmol_c L^?1. Both top and root growth of melon seedlings were enhanced regardless of varieties, dry matter weights were maximized at 4 g L^?1 PG application. The Ca uptake of melon seedlings was promoted by PG application in all the varieties. It was suggested that the relative root growth rate of melon seedlings was closely related to the Ca uptake of melon seedlings.     

Cadmium,Lead, Copper,Zinc, and Nickel in Lettuce and Dry Beans as Related to Mehlich-3 Extraction in Three Brazilian Latossols

Lettuce (Lactuca sativa L.) and dry beans (Phaseolus vulgaris L.) were grown in three Brazilian Red-Yellow Latossols (Oxisols) in greenhouse conditions with cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), and nickel (Ni) applied to soils in treatments arranged as a randomized complete block design. Plant metals were analyzed in lettuce shoots and dry beans roots, stems, leaves, and seeds. After plant growth, soil samples from the pots were extracted with Mehlich-3 (M-3) for metal availability evaluation. The release of Ni in the M-3 extraction was dependent on the soil exchangeable aluminum (Al^{3 +}). Mehlich-3 was efficient for determination of availability of Cd, Pb, Cu, Zn, and Ni for dry beans and availability of Cd and Ni for lettuce. The dry bean leaves Cd, Pb, Cu, Zn, and Ni were highly correlated with their recovering from soils with M-3. The same was observed for Cd and Ni in lettuce shoots and the M-3 recovered metals from soils.     

Comparison of Analytical Methods for Quantifying the Levels of Lead,Cadmium, Chromium,and Nickel in Mineral Fertilizers and Industrial By-products

The control of contaminants in fertilizers and industrial by-products is fundamental to safe food production, and it requires low-cost, reliable test methods. The aim of this study was to evaluate the performance of the USEPA 3051a and alternative analytical methods [concentrated hydrochloric acid (HCl), 10 percent HCl, 10 percent sulfuric acid (H₂SO₄), and 50 mmol L^?1 diethylenetriaminepentaacetic acid (DTPA)] for quantifying the levels of lead, cadmium, chromium, and nickel in zinc and/or copper sources. The sample digestions with concentrated HCl, H₂SO₄, and nitric acid (HNO₃) (USEPA 3051a) were heated. Extraction without heating and stirring was employed in 10 percent HCl and 50 mmol L^?1 DTPA methods. The Graybill’s modified F-test, t-test for mean error, and the linear correlation coefficient analysis were used to compare test method performance. Equivalent results to USEPA 3051a were found with the following methods: DTPA for the extraction of lead in zinc sources and concentrated HCl and H₂SO₄ for the extraction of cadmium and chromium in copper sources. However, the absolute values of cadmium, chromium, and nickel recovered by the use of H₂SO₄ were greater regardless of the source. The greater extraction of contaminants in the evaluated methods suggests that there is need to review the official method if the aim is to quantify the total levels of these elements in raw materials and mineral fertilizers.     

Distribution and development of sclerotium grains as influenced by aluminum status in volcanic ash soils

Granulometric and clay mineralogical analyses were performed on soil types differing in their genesis which had been formed on the raised coral limestone terraces and plateaux under the perhumid subtropical maritime climate of the Ryukyu Islands. The amount of clay fraction in Rendzina-like soil on the lower terrace was relatively small (8-34%) and decreased with depth, while those in Terra fusca-like soils on the middle terraces and in Terra rossa-like soil on the plateau were very large (45–78%) suggesting the occurrence of clay migration.

Rendzina-like soil mainly contained illite and metahalloysite with a moderate amount of mixed layered mineral consisting of illite and vermiculite, and a small amount of vermiculite, Al-vermiculite, goethite, and quartz. Clay mineral composition of Terra fusca-like and Mottled Terra fusca-like soils was similar to that of Rendzina-like soil except that the content of illite was lower in these soils. Terra rossa-like soil, on the other hand, mainly contained Al-vermiculite, metahalloysite, and gibbsite, indicating a highly advanced stage of hydroxyaluminium interlayering. Differences in clay mineral composition from that of Rendzina, Terra fusca, and Terra rossa soils in the European countries were recognized, in that mont-morillonite was absent and hydroxyaluminium interlayering actively proceeded in the soils studied here. This finding is considered to reflect the rapid alteration and intense hydroxyaluminium interlayering of clay minerals under the perhumid subtropical conditions.     

大庆龙凤湿地土壤重金属空间分布特征

对大庆龙凤湿地土壤Cu,Cr,Cd,Zn,Pb和As六种重金属元素的空间分布特征进行了研究.结果表明:湿地土壤表土层(0-10 cm)Cu,Cr,Cd,Zn,Pb和As在水平分布上的变化较大,除Cr和Zn外,Cu,Cd,Pb和As含量均低于松嫩平原土壤重金属含量平均值;在土壤剖面中,Cu,Cr,Cd和As都随着土层深度的增加逐渐减少,而Pb和Zn则是先增加后减少,这与区域内土壤的理化性质、成母土质、岩石风化及淋溶作用有极大的关系.Cu,Cd,Zn,Pb,As五种重金属元素之间,除Cu和As间相关关系不显著外,其余各重金属元素之间均呈极显著的正相关关系,而Cr只与Cu呈显著正相关,与其他各重金属元素之间均未表现出显著的相关性,由此推测Cu,Cd,Zn,Pb,As元素的来源可能相同,且具有一定的共生组合性,而Cr则受湿地周边复杂环境及人为随机因素的影响较大.     

西藏尼洋河水体重金属分布特征及风险评价

重金属含量是影响水生态环境安全的重要因素,该文意在探索西藏河流水体重金属变化规律。研究了雅鲁藏布江第二大支流尼洋河的Zn、Cu、Mn、Cd、Fe 5种重金属含量时空变化特征和相关性,以及迁移变化机理,对重金属富集程度和污染风险进行了评价。结果表明：尼洋河重金属含量源头较低,中上游位置有突变。Fe、Mn、Cd是影响水质变化的敏感因子。Zn、Cu、Mn含量平水期＞枯水期＞丰水期。丰水期重金属含量主要受人类活动或水文气象活动影响,平水期及枯水期的Zn、Cu、Mn、Fe含量主要受自然过程影响,枯水期Cd主要受人类活动影响。水库对重金属富集有一定的影响。河源和中下游河段污染较轻,上游河段重金属综合污染指数最高。     

吉林省畜禽粪便自然堆放条件下粪便/土壤体系中Cu、Zn的分布规律

本文通过对不同养殖场鸡、猪、牛粪便自然堆放条件下粪便和土壤样品的采集和实验室分析,研究了吉林省部分养殖场不同类型畜禽粪便Cu、Zn含量,以及粪便自然堆放对土壤Cu、Zn含量的影响。结果表明,鸡粪、猪粪和牛粪中Cu的含量范围和均值分别为7.12～26.04mg·kg-（1风干样,下同）（均值18.24mg·kg-1）、87.99～463.7mg·kg-（1均值243.6mg·kg-1）、3.95～27.63mg·kg-（1均值12.28mg·kg-1）;Zn的含量范围和均值分别为179.2～340.8mg·kg-（1均值276.9mg·kg-1）、140.5～455.8mg·kg-（1均值381.8mg·kg-1）、150.5～292.3mg·kg-（1均值188.1mg·kg-1）。不同类型粪便中Cu、Zn含量均是猪粪〉鸡粪〉牛粪,但不论是哪种类型的畜禽粪便重金属含量均是Zn〉Cu。在自然堆放条件下,鸡粪和猪粪中的Cu可从粪便向底土迁移,迁移量随粪便中Cu含量的增加而增加,并主要积累在土壤表层,而牛粪在自然堆放过程中对底土的Cu含量影响不显著,粪底土Cu含量分布规律为猪粪底土〉鸡粪底土〉牛粪底土;鸡粪、猪粪和牛粪中的Zn也可向底土迁移,使粪底土Zn含量有不同程度的增加,但主要积累在粪底土的表层,且不同类型粪便底土Zn含量差异不明显。     

盐分胁迫下番茄盐分离子和重金属的分布特征

采用盆栽试验方法研究了不同盐分含量处理下番茄不同器官盐分离子（Na＋、K＋、Ca2＋）和重金属离子（Cd2＋、Pb2＋、Cr2＋、Zn2＋、Cu2＋、Ni2＋）的分布特征,探讨盐分离子对番茄不同器官吸收重金属离子的影响机制,为重金属污染盐渍土壤的农业可利用性评价提供科学依据。结果表明,番茄根、茎、叶和果实Na＋含量均随盐分含量增加而增加;番茄根K＋含量随盐分含量增加小幅上升,茎K＋含量则显著下降,叶K＋含量无显著变化;番茄各器官Ca2＋含量随盐分含量增加无明显变化。番茄根Cd、Pb、Cr、Zn和Cu含量以及番茄茎、叶Cd含量均随盐分含量增加而增加;番茄根Ni含量、番茄茎叶Pb、Cr、Ni、Zn和Cu含量以及番茄果实各重金属含量受盐分含量变化影响不大。因此,土壤盐分含量的增加对番茄根部吸收重金属（Ni除外）有促进作用。     

Evaluation of the modified olsen extracting reagent for Copper,Zinc and Manganese

Abstract

The Modified Olsen (MO) extracting reagent is used extensively as a soil test extractant in Latin America. Little correlation or calibration research hasbeenreportedonit, however, especially for the micronutrients. wheat, corn, and soybeans were grown successively in the greenhouse to evaluate Cu, Zn, and Mn, respectively. Lime and micronutrient variables (one micronutrient per crop) were imposed on six soils representing four orders. After each cropping the soils were extracted with MO and with three other extracting reagents for which there are referenced critical levels: Mehlich‐1 (Ml), Mehlich‐3 (M3) and Soltanpour‐Schwab (SS). The correlations between nutrient uptake and the concentrations extracted were fairly similar for the four solutions, but were better for Mn and Zn than Cu. The poor relationship for Cu occurred partly because a maximum wheat concentration of about 10 mg/kg was reached, creating a curvilinear function. The amounts of nutrients extracted by the four reagents were also well correlated except for that between MO and Ml for Cu. Using these relationships, along with critical levels previously determined with reference extractants, the MO critical levels for Cu, Zn, and Mn were estimated to be 0.3, 1.0, and 3.0 mg/L, respectively     

Interaction of Iron with Copper,Zinc, and Manganese in Wheat as Affected by Iron and Manganese in a Calcareous Soil

Iron (Fe) availability is low in calcareous soils of southern Iran. The chelate Fe-ethylenediamine di (o-hydroxy-phenylacetic acid) (Fe-EDDHA), has been used as an effective source of Fe in correcting Fe deficiency in such soils. In some cases, however, its application might cause nutritional disorder due to the antagonistic effect of Fe with other cationic micronutrients, in particular with manganese (Mn). A greenhouse experiment was conducted to evaluate the influence of soil and foliar applications of Fe and soil application of manganese (Mn) on dry matter yield (DMY) and the uptake of cationic micronutrients in wheat (Triticum aestivum L. var. Ghods) in a calcareous soil. Results showed that neither soil application of Fe-EDDHA nor foliar application of Fe sulfate had a significant effect on wheat DMY. In general, Fe application increased Fe uptake but decreased that of Mn, zinc (Zn), and copper (Cu). Application of Mn increased only Mn uptake and had no significant effect on the uptake of the other cationic micronutrients. Iron treatments considerably increased the ratio of Fe to Mn, Zn, Cu, and (Mn + Zn + Cu). Failure to observe an increase in wheat DMY following Fe application is attributed to the antagonistic effect of Fe with Mn, Zn, and Cu and hence, imbalance in Fe to (Mn + Zn + Cu) ratio. Due to the nutritional disorder and imbalance, it appears that neither soil application of Fe-EDDHA nor foliar application of Fe-sulfate is appropriate in correcting Fe deficiency in wheat grown on calcareous soils. Hence, growing Fe-efficient wheat cultivars should be considered as an appropriate practice for Fe chlorosis-prone calcareous soils of southern Iran.     

间歇性降雨对土壤团聚体粒级及磷、铜、锌富集的影响

探讨间歇降雨条件下土壤干湿交替对团聚体粒级动态变化的影响,对加深径流泥沙运移和分选机制的理解、揭示土壤微量元素随地表径流迁移的规律具有重要意义。通过37d内的5场间歇性人工降雨实验,观测了降雨激发的团聚体破碎过程和降雨间歇段干缩过程导致的团聚体粒径分布的动态变化,并通过分析不同团聚体粒级总磷、铜、锌含量的动态变化,评估了间歇降雨对土壤污染物富集特征的影响。结果表明,间歇性降雨导致的土壤干湿交替引发了剧烈的团聚体粒级周转,团聚体稳定性随实验推移呈总体退化状态,具体体现在>250μm微团聚体的比例随实验推移显著下降,而<250μm微粒的比例显著上升(P<0.05)。团聚体粒径分布的变化引起了不同粒径磷、铜、锌含量的同步变化,三种元素从>250μm向<63μm粒级逐渐转移,造成<63μm粒级内各元素浓度在实验末期达到最高,这意味着间歇性降雨引起的团聚体结构退化和<250μm微粒的增加及微量元素富集会加大水土流失及伴随污染物排放的风险。本研究揭示了间歇性降雨引起的土壤团聚体结构变化及对泥沙分选和元素迁移过程的影响,为土壤侵蚀引起的横向物质运移机制提供了...