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1.
A. Rahman Barzegar Ahmad Koochekzadeh Baoshan Xing Stephen J. Herbert 《Water, air, and soil pollution》2005,161(1-4):97-112
In the southwest of Iran over 130,000 ha of land are under sugarcane (Saccarum officinarum). In these sugarcane fields, about 400 kg ha?1 diamonium phosphate (DAP) and 400 kg ha?1 urea are applied annually. Four sugarcane growing sites were selected for this study: Haft-tapeh, Karoon, Shoeibieh and Ghazali with cultivation histories of 36, 20, 2 and 1 years, respectively. For each area, soil samples (0–30 cm) were taken from a transect of uncultivated, and both furrows and ridges of cultivated land. Electrical conductivity (EC), pH, clay, and calcium carbonate and organic carbon (OC) contents, Cl, Cd, Ni and Zn of 101 soil samples were measured. Cadmium profile distribution to a soil depth of 300 cm was determined, and the heavy metal concentrations in sugarcane and the associated soil samples of the three sugarcane sites were measured. The Cd and Ni contents among the sugarcane sites differed where Cd was related to clay content and Ni was related to OC content of soils. Cadmium content in sugarcane cultivated soil was lower compared to uncultivated soil even after years of application of P fertilizers. Nickel and Cd contents of sugarcane were much higher than levels in top soils but there was no significant relationship between Cd or Ni contents of sugarcane and soil chemical properties. The Zn content of soils decreased as either EC or Cl concentration of soils increased. There were no significant differences in Zn contents between different sugarcane sites and also between cultivated and uncultivated soils. Results also indicated that Cd was accumulated in bagasse and Ni was primarily accumulated in bagasse and molasses, but these heavy metals of white sugar were lower than the detectable values. 相似文献
2.
It was postulated by Brinkman (1970) that low clay contents in the surface horizon of paddy soils (Planosols) are caused by clay destruction through ferrolysis. In an effort to test this, a rice profile from the site of Brinkman's Eutric Planosol (Salna, Bangladesh) and a neighbouring forest soil (Dystric Cambisol) of the same parent material and particle-size distribution (Bhawal National Park) were investigated. The micro-structure, particle-size distribution, mineral contents, pedogenic oxides, contents of Zr, Ti and K of the fine earth and individual fractions and also the exchangeable ions were studied. The clay fraction of both soils were chloritised by interlaying of hydroxy-Al in the smectite interlayers in the surface horizons and got stabilized. As a result CEC showed some decrease. The forest profile has a loose and uniform brown-yellow surface horizon and is relatively rich in coarse sand at 62–75 cm depth which might be caused by a strong termite activity as observed during sampling. On the contrary, the frequent and alternate reducing and oxidizing conditions have resulted in gleying the top soil and forming iron-oxide films on the surface of aggregates during dry periods in the paddy soil. An evaluation of all results shows that a little clay destruction and an enrichment of silt in the top soil through vertisol formation and also through primary parent material stratification were the reasons for low clay content in epipedons. In forest soil there was a little clay migration, while the epipedon of the paddy soil had low clay in addition, because of selective erosion during heavy rains following the destruction of structure by puddling. The ferrolysis as a dominant factor for a clay-low epipedon is improbable, because the clay loss of the neighbouring forest soil can not be explained by ferrolysis. 相似文献
3.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):2033-2045
Abstract Soils under the main mangrove (Rhizophora racemosa and Avicennia germinans) forest in the Niger Delta, Nigeria, were characterized, and their capacities to retain heavy metals were examined by using soil column leaching experiments, using 20 mg L?1 Cu, 50 mg L?1 Zn, 20 mg L?1 Cd, and 100 mg L?1 Mn solutions. At the end of the leaching experiments, soil samples from each column were divided into two layers (0–5 cm and 5–10 cm) and analyzed for total metal retained. The fractionation of heavy metals in the surface soil samples (0–5 cm) was investigated by the sequential extraction technique. The study showed that the soils were influenced by tidal flow and characterized by the presence of very fine textured, thin (0–5 cm) to moderately thick (10–15 cm) layer of alluvium (mud) on the surface. The fibric soil material beneath the surface mud varies in thickness from about 70 to 100 cm, and beyond the histic layer is the plastic, very sticky, massive clay. In situ, the soils were neutral in reaction (pH 7.0–7.2), but became strongly acid (pH 3.3–4.8) upon drying. They are saline, high in soluble salts, highly reduced, with CEC that is low in the fibric layer, but high in the mineral, clayey subsoil horizon. The soils are saturated with water for much more than 30 days in a year and have fiber content that is more than 40 cm thick, with the fibric sphagnum constituting more than three‐fourths by volume to a depth greater than 90 cm. The soils, classified as Typic Sphagnofibrists, sequestered considerable amounts of copper (Cu), zinc (Zn), cadmium (Cd), and manganese (Mn) with most of the metals retained in the surface soils. The anthropogenic heavy metals were mostly adsorbed probably to the negatively charged sites of organics and clay. These loosely bound metals may be desorbed and reenter the aqueous phase, thus becoming a secondary source of metal pollution. 相似文献
4.
Most of the carbon (C) in terrestrial ecosystems is stored in the mineral soil layers. Thus, the response of the mineral soil to potential increases in temperature is crucial for the prediction of the impact of climate change on terrestrial ecosystems. Samples from three mineral soil layers were collected from eight mature forest sites in the European network CARBOEUROFLUX and were incubated at four temperatures (4, 10, 20 and 30°C) for c. 270 days. Carbon mineralization rates were related to soil and site characteristics. Soil water holding capacity, C content, nitrogen (N) content and organic matter all decreased with soil depth at all sites, with significantly larger amounts of organic matter, C and N in the top 0–5 cm of mineral soil than in the deeper layers. The conifer forest soils had significantly lower pH, higher C/N ratios and carbon contents in the top 5 cm than the broadleaf forest soils. Carbon mineralization rates decreased with soil depth and time at all sites but increased with temperature, with the highest rates measured at 30°C for all sites. Between 50 and 70% of the total C respired after 270 days of incubation came from the top 5 cm. The percentage C loss was small in all cases, ranging from 1 to 10%. A two‐compartment model was fitted to all data to derive the labile/active and slow/recalcitrant fractions, as well as their decomposition constants. Although the labile fraction was small in all cases, we found significantly larger amounts of labile C in the broadleaf forest soils than in the conifer forest soils. No statistically significant differences were found in the temperature sensitivity parameter Q10 among sites, soil layers or between conifer and broadleaf soils. The average Q10 for all soils was 2.98 (± 0.10). We found that despite large differences among sites, C mineralization can be successfully predicted as a combined function of site leaf area index, mean annual temperature and content of labile carbon in the soil (R2 = 0.93). 相似文献
5.
Enrichment of C and N in soils of southeastern Niedersachsen after deepening of top soil In a comprehensive study, the effects of deepening of top soil during the last 20 years on C-organic-and N-total-masses of some selected arable land sites have been analyzed. The sampling sites represent soil groups predominating in southeastern Niedersachsen. In 145 plots of 22 agricultural farms with the rotation sugar beets/winter wheat/winter barley, sugar beets/winter wheat/winter wheat respectively, the actual depth of plow horizon varies from 32 to 38 cm in summer. Organic matter has been analyzed in 125 soils. A C-org.- and N-total-balance sheet has been prepared for the time after deepening of the top soils. In luvisols with a top soil deepening of about 10 cm a period of 15 years has been necessary for aquirement of the C-content before deepening. A C-enrichment up to 15 t/ha was recorded with incorporation of plant residues in the last 15 years. During this period up to 1,5t of N/ha accumulated assuming constant C/N-ratios. For chernosems, a similar rate has been determined. In sandy cambisols, the short period of observation of 10 years and less after top soil deepening did not permit a complete reenrichment with organic matter. The ”?potentially”? possible enrichment with organic C amounts to 14–17 t/ha (= 1,4–1,7 t N). Furthermore, luvisols gave a significant correlation between clay- and C-amounts of non deepened soils. A weak interrelation has also been found between clay content and the enrichment potential of organic matter in these soils. 相似文献
6.
[目的]揭示呼伦贝尔草地不同道路影响下路边土壤表层颗粒组成的空间变异特征,为道路沿线水土流失治理提供科学依据。[方法]对省道S203和土路的坡顶、坡底、轮坑以及0—30 m样带和30—210m样带进行实地采样,经风干处理后用吸管法测定了颗粒组成,采用ArcGIS 10.0软件进行的克里金插值和半方差分析。[结果]省道S203,路边土壤粉粒和石砾含量空间变异较大,变异系数分别为95.96%和80.05%。道路边坡附近粉粒和黏粒含量少,随着与路边距离的增加,粉粒和黏粒含量增加;而土路对路边土壤黏粒含量的影响较大,车轮碾压轮坑附近黏粒含量多;道路和沿线人类活动对石砾和粉粒含量的影响强至中等。[结论]受人类活动影响,研究区道路沿线土壤表层不同颗粒组成空间分布发生变化,而黏粒含量形成了沿着道路呈带状分布的空间分布特征。 相似文献
7.
Root growth and yield of sugar-beets were studied on two Belgian silt loam soils and one alluvial clay soil after subsoiling to a depth of 60 cm. The removal of the plough sole layer, characterized by penetration resistances > 3 MPa, resulted in an increase of the root quantity and a higher availability of water. As a consequence, a mean yield increase of 5 tons/ha for sugar-beets was found on the subsoiled plots in drier years. The yield increase was accompanied by a higher uptake of nutritive elements. 相似文献
8.
深松35 cm可改善潮棕壤理化性质并提高小麦和玉米产量 总被引：5，自引：2，他引：3
9.
深松对春玉米根系形态特征和生理特性的影响 总被引：14，自引：11，他引：14
为研究深松对春玉米根系形态特征和生理特性的影响。以郑单958和先玉335为供试品种,设旋耕(R)、深松加旋耕(S+R)2个处理,于2012和2013年进行田间试验。结果表明,深松可以显著提高2个品种春玉米实测产量(P0.05)、春玉米乳熟期和完熟期根干质量(P0.05)且40 cm以下土层尤为明显。2个品种春玉米30 cm土层处的株、行间根幅均表现为S+R小于R处理,其中行间根幅的差异达到了显著水平(P0.05),单株根条数和比根长均表现为S+R显著高于R处理(P0.05)。乳熟期60 cm以下土层根系活力S+R高于R处理且随着土层的加深差异逐渐增大,超氧化物歧化酶和过氧物酶活性在吐丝期和乳熟期各土层S+R均高于R处理,而丙二醛含量低于旋耕处理。深松促进根系特别是下层根系干质量的增加,增加根系纵深分布,春玉米根系重心下移,并保持较高的生理活性,是其能够增产的重要原因。该文可为春玉米高产栽培提供依据。 相似文献
10.
耕作方式对土壤水分入渗、有机碳含量及土壤结构的影响 总被引：14，自引：6，他引：14
为探明不同耕作方式对土壤剖面结构、水分入渗过程等的作用机理,采集田间长期定位耕作措施(常规耕作、免耕、深松)试验中的原状土柱(0~100 cm)及0~10 cm、10~20 cm、…、90~100 cm环刀样、原状土及混合土样,通过室内模拟试验进行了0~100 cm土层土壤入渗过程和饱和导水率的测定,分析了不同土层的土壤有机碳含量、土壤结构特征及相互关系。结果表明:从土柱顶部开始供水(恒定水头)到水分全部入渗到土柱底部的时间为:常规耕作免耕深松;土柱土壤入渗速率和累积入渗量为:深松免耕常规耕作;土柱累积蒸发量为:常规耕作免耕深松。土壤的饱和导水率表现为:0~10 cm和50~60 cm土层,免耕深松常规耕作;20~50 cm和60~100 cm土层,深松免耕常规耕作。随土层的加深,0.25 mm水稳性团聚体含量和土壤有机碳含量均表现为先增加(10~20 cm)再降低的趋势。在0~40 cm土层和80~100 cm土层,均以深松处理0.25 mm水稳性团聚体含量最高。在60 cm以上土层,土壤有机碳含量表现为:免耕深松常规耕作,而60 cm土层以下土壤有机碳显著降低,均低于4 g·kg?1,且在70 cm以下土层,常规耕作免耕深松。综上,耕作措施能够改变土壤有机碳含量,改善土壤结构,促进土壤蓄水保墒;深松更利于水分就地入渗,而免耕则更利于有机碳的提升和水分的储存,其作用深度在0~60 cm土层。 相似文献
11.
农田土壤剖面反硝化活性及其影响因素的研究 总被引：6，自引：0，他引：6
用培育法研究了我国3种农田土壤剖面各层土壤的反硝化活性及其影响因素。结果表明，潮土剖面各层上壤中以0～20cm土壤的反硝化活性为最高，培育20天时的反硝化活性达到49％，而下层土壤的反硝化活性，除52～65cm土层外，则都很低；加葡萄糖或肥土清液，明显地提高了各层土壤的反硝化活性，且以前者的作用更大些，但加磷则无此作用。黄泥土（中等肥力）剖面中各层土壤的反硝化活性，也以0～20cm土壤为最高。培育20天时的反硝化活性达到74％，随剖面深度的加深，反硝化活性逐渐减小。加葡萄糖和肥土清液对表土的反硝化活性没有明显的影响，却明显地提高了40～100cm各层土壤的反硝化活性。但加磷对各层土壤的反硝化活性则都无明显的影响。红壤（花生地）剖面中各层土壤的反硝化活性都极低。加葡萄糖或肥土清液能提高表土的反硝化活性，但对其下各层土壤的反硝化活性却没有影响。加磷未能提高各层土壤的反硝化活性。相关分析表明，培育20天土壤反硝化活性与土壤有机质含量呈极显著的正相关（r＝0．827* *），而与土壤速效磷含量和土壤pH无此相关性。 相似文献
12.
Ten years after the Chernobyl disaster the Cs-137 migration of typical soils of North Germany (Folic Histosol, Haplic Podzol, Dystric Gleysol, Eutric Fluvisol) has been investigated and compared to their Cs distribution in 1986. In 1986 nearly 90% of the Cs-137 occurred in the upper 1–5 cm soil sections, whereas it was 50–70% in 1996. The more regular distribution ten years after the accident shows that migration processes have taken place. The Podzol presented a high migration with marked Cs-137 losses in the top soil. The Gleysol showed the lowest migration down to 10 cm depth. A nearly similar pattern at the top was found within the Histosol, however, a ratio of 10% Cs-137 in the 10–15 cm section indicated a deeper migration. Despite the large clay content, the Fluvisol showed a regular Cs distribution within its profile, probably resulting from cattle steps and/or peloturbation. 相似文献
13.
This study aimed at clarifying whether a notable group of soils of the Jæren region, SW Norway, with deep humus‐rich top soils support a man‐made genesis. Four sites were investigated. The soils are characterized by thick top soils of 45, 70, 80, and 90 cm, which are enriched in soil organic matter and often also in artifacts, like fragments of potter's clay, indicating an anthropogenic origin. Soil pH ranges from 5.4 to 6.2 (H2O) and 4.4 to 5.3 (CaCl2), respectively. Soil organic C (SOC) contents range from 6.4 to 51.6 g kg?1 and N contents vary between 0 and 2.9 g kg?1. Increased P contents of up to 2,924.3 mg kg?1 total P (Pt) and 1,166.4 mg kg?1 citric acid‐soluble phosphorus (Pc) in the humus‐rich top soils support the assumption of an anthropogenic influence. Although many characteristics indicate an anthropogenic genesis, one soil lacks the required depth of 50 cm of a plaggen horizon and cannot be classified as Plaggic Anthrosol (WRB) and Plagganthrept (US Soil Taxonomy). As the requirement is 40 cm in the German system, all soils can be classified as Plaggenesch. The formation of these soils is related to human activity aiming at increasing soil fertility and overcoming the need of bedding material, the basic aims of the plaggen management in Europe. Highest P contents ever found for this kind of soils and references from the literature indicate that the formation of the soils in Norway started at Viking time, hence, being older than most other Plaggic Anthrosols. 相似文献
14.
Addition of a clay subsoil to a sandy topsoil changes the response of microbial activity to drying and rewetting after residue addition – a model experiment 
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下载免费PDF全文 The effect of drying and rewetting (DRW) on C mineralization has been studied extensively but mostly in absence of freshly added residues. But in agricultural soils large amounts of residues can be present after harvest; therefore, the impact of DRW in soil after residue addition is of interest. Further, sandy soils may be ameliorated by adding clay‐rich subsoil which could change the response of microbes to DRW. The aim of this study was to investigate the effect of DRW on microbial activity and growth in soils that were modified by mixing clay subsoil into sandy top soil and wheat residues were added. We conducted an incubation experiment by mixing finely ground wheat residue (20 g kg–1) into top loamy sand soil with clay‐rich subsoil at 0, 5, 10, 20, 30, and 40% (w/w). At each clay addition rate, two moisture treatments were imposed: constantly moist control (CM) at 75% WHC or dry and rewet. Soil respiration was measured continuously, and microbial biomass C (MBC) was determined on day 5 (before drying), when the soil was dried, after 5 d dry, and 5 d after rewetting. In the constantly moist treatment, increasing addition rate of clay subsoil decreased cumulative respiration per g soil, but had no effect on cumulative respiration per g total organic C (TOC), indicating that the lower respiration with clay subsoil was due to the low TOC content of the sand‐clay mixes. Clay subsoil addition did not affect the MBC concentration per g TOC but reduced the concentration of K2SO4 extractable C per g TOC. In the DRW treatment, cumulative respiration per g TOC during the dry phase increased with increasing clay subsoil addition rate. Rewetting of dry soil caused a flush of respiration in all soils but cumulative respiration at the end of the experiment remained lower than in the constantly moist soils. Respiration rates after rewetting were higher than at the corresponding days in constantly moist soils only at clay subsoil addition rates of 20 to 40%. We conclude that in presence of residues, addition of clay subsoil to a sandy top soil improves microbial activity during the dry phase and upon rewetting but has little effect on microbial biomass. 相似文献
15.
深松深度对砂姜黑土耕层特性、作物产量和水分利用效率的影响 总被引：3，自引：1，他引：2
研究深松深度对砂姜黑土耕层特性、作物产量和水分利用效率的影响,可为构建砂姜黑土合理耕层的耕作深度指标提供依据。本研究基于多年定位大田试验,采用大区对比设计,设置4个深松深度(30 cm、40 cm、50 cm、60 cm)处理,以旋耕(RT,平均耕作深度为15 cm)作为对照,研究不同深松深度对土壤紧实度、土壤三相比(R)值、作物根系形态、作物产量和水分利用效率的影响。研究结果表明,深松深度增加能显著降低土壤紧实度,使土壤的三相比(R)更加合理,进而促进作物根系生长。不同深松深度中,深松60 cm处理的土壤紧实度和三相比(R)值与对照相比降幅最大,深松40 cm处理的冬小麦根系生物量最大,深松50 cm处理的夏玉米根系生物量最大。深松不仅增加作物产量,还提高作物水分利用效率。深松30 cm处理的周年作物产量最高,比对照增产12.2%,但与深松40 cm处理差异不显著。深松50 cm处理的周年水分利用效率最高,但与深松30 cm和深松40 cm处理差异不显著。深松30 cm、40 cm和50 cm的周年水分利用效率比对照分别增加9.1%、8.8%和12.7%。因此,砂姜黑土适宜的深松深度为30~40 cm。 相似文献
16.
The sorption of zinc (Zn) by two acid tropical soils, Mazowe clay loam (kaolinitic, coarse, Rhodic Kandiustalf) and Bulawayo clay loam (coarse, kaolinitic, Lithic Rodustalf), was studied over a wide range of Zn solution concentrations. Samples of the two soils used in the experiments were collected at both uncleared, uncultivated (virgin) sites and cultivated sites. The two virgin soils showed similar abilities to bind Zn. Mazowe soil (40 g organic matter kg?1) presented the highest affinity for Zn. Yet, Bulawayo soil (23.5 g organic matter kg?1) sorbed almost the same amount. Bulawayo soil had higher pH and Fe and Mn-oxide content than Mazowe soil. Once cultivated, the two soils behaved quite differently. After 50 years, Mazowe soil had lost 60% of its organic matter and effective cation exchange capacity (ECEC). In this soil, Zn sorption capacity had also been decreased by 60%. Clearing and 10 years under cultivation had affected neither the organic matter content nor the ECEC of Bulawayo soil. For this soil, Zn sorption was even higher in the cultivated soil, presumably due to an increase in the amount of Fe and Mn oxide from subsoiling. Zinc sorption was dependent upon pH, with retention dramatically increasing in the pH range 6–7. Sorption occurred at pH values below the point of zero charge (PZC), indicating that the sorption reaction can proceed even in the presence of electrostatic repulsion between the positively charged soil surface and the cation. In the two soils, the reversibility of the sorption reaction was very low. More than 90% of the sorbed Zn was apparently strongly bonded. 相似文献
17.
I. O. Plekhanova 《Eurasian Soil Science》2017,50(4):491-497
Sandy loamy agrosoddy-podzolic soils and plants growing on them were studied. The soils had been treated with sewage sludge from the Lyubertsy aeration station applied as organic fertilizer for 5–10 years before 1990. Initially, these soils were used for cultivating vegetables and fodder crops. The content and mobility of heavy metal compounds increased in the plow horizons of studied soils under the influence of sewage sludge. The concentrations of Cd and Zn exceeded the tentative permissible concentrations (TPC) for these elements by 8–16 and 2–4 times, respectively. The contaminated layer was found at the depths within 30–50 cm, which attests to a low migration rate of heavy metals added to the studied soils with sewage sludge (SS) 25 years ago. The concentration of Cd exceeded the maximum permissible concentration (MPC) of this element in all vegetable and fodder crops cultivated on the studied soils. The content of heavy metals in plants differed by three–five times in dependence on the capacity of particular plants to accumulate them. The period of soil self-purification from heavy metals was found to depend on the soil contamination level and element mobility, as well as on the element removal with harvested crops and with soil water flows. The maximal time of achieving the normal level of Cd concentration was estimated as 288 years for maximally contaminated soils; the corresponding values for Cu and Zn were estimated as 74 and 64 years, respectively. 相似文献
18.
Friedrich Lehnardt 《植物养料与土壤学杂志》1998,161(1):41-50
Impact of liming and fertilization on ionic exchange and chemical composition of soil solutions from four forest sites in the colline region of Hesse Between February 1985 and July 1987 soil seepage experiments were carried out on fertilizer trial plots in mature beech stands of four forest districts of Hesse. Encompassed by this study are in addition the most important results from soil-chemical analyses of the subsequent years 1988 to 1991. Aim of the investigations was to study the influence of liming and K/Mg-fertilization on the chemical composition of soil and soil solution under different site conditions. In the percolated soil solution liming did not led to a significant pH increase in subsequent years. In contrast, in some cases the pH level dropped by 0.1 to 0.2 units on average and Al-concentration increased correspondingly. In most cases, fertilization led to a significant increase in soil solution concentrations of the metal cations potassium, calcium and magnesium, especially at a depth of 50 cm. On those trial plots where a pH decrease was observed, the concentrations of K, Ca and Mg exhibited either a slight or no increase at all. Furthermore on some trial sites with freely drained soils, liming led to a faster mineralisation of the humus layer and thus to an increase of nitrate contents in the percolated soil solution from about 1–2 mg/l to 10–20 mg/l on average. Increased concentrations of sulfate and in most cases also of heavy metals (Mn, Zn, Cu. Cd) were observed in the soil solution which was attributed to the mobilizing effect of Ca-fertlization. In general, the mobility of most chemical parameters showed a slight increase following liming and soil tillage. Even after 5 to 8 years considerably higher pH-values and base saturation were evident in limed and fertilized soils, especially in the top 15 cm of soil profiles. 相似文献
19.
W. Ehlers 《植物养料与土壤学杂志》1977,140(1):79-90
Physical properties of silt crusts The physical properties of silt crusts of two locations within the eastern part of the Solling mountains in Western Germany were investigated. They were formed downhill on top of sloping grey brown podzolic soils derived from loess during heavy rainfall, which caused aggregate breakdown and erosion. The crusts were several cm in thickness. They consist of 80% coarse silt (20–60μ), of 12% medium silt (6–20μ) and of 5% clay (<2μ). The content of organic matter is low. Porosity of the silt crusts is 47–51 vol.%. Compressed silt crusts with 40% porosity contain only 2,5 vol.% of large pores > 15μ, According to this the unsaturated hydraulic conductivity remains almost constant when tensions are increasing, but it drops immediately, when the 15μ pores drain at 200cm H2O pressure. The saturated conductivity varies with porosity in the range of 10–50 cm/day. But in the Ap-horizon of a grey brown podzolic soil with higher contents in clay and organic C the saturated conductivity varies with porosity in the range of 10–10 000 cm/day. Only during rainstorms with high intensity silt crusts will impede rapid water infiltration into the underlying grey brown podzolic soil. 相似文献
20.
Axel Gzik Matthias Kuehling Ingo Schneider Bernd Tschochner 《Journal of Soils and Sediments》2003,3(1):29-34
In soils, animals and plants from selected sites in the Rustenburg mining area, a part of the South African ore belt, the
heavy metal burden was examined. These sites belong to different soil types and are characterized by different land-use (agriculture,
grassland). The heavy metal contamination of the soil samples is relatively high and is dominated by chromium and nickel,
metals, which are extracted in the mine near the sampling sites. These high heavy metal concentrations had no clear inhibitory
influence on micro-organisms or the enzyme activity of soils. It appears that the high clay content of the soils may counteract
the influence of heavy metals. On the other hand, tolerant microbial populations may have been established. In addition, the
investigated culture plants there was no correlation between the heavy metal content of the soils and the concentrations in
roots and shoots. The dangerous, potential contamination of organs in humans seems to be modest, with the exception of tobacco
leaves. The heavy metal content of tissues in the examined animals reflect the environmental habitat in situ with no obvious
influence on the health of the animals. 相似文献