俄罗斯土壤科学的研究现状

通过与俄罗斯著名土壤学家来访时的交流，作者介绍了当今俄罗斯土壤科学的研究状况，包括俄罗斯主要土壤科学研究研究机构设置、主要研究内容和趋势，使我国土壤科学工作者对曾是近代土壤科学的发源地俄罗斯土壤科学的最新进展有一概括了解。     

Torus-shaped pedological features associated with soil microorganisms

Torus-shaped features 1–7 urn in diameter were found on the smooth surfaces of the structural units of a Red Podzolic Soil (Udic Haplustalf) B horizon and on the smooth surfaces within the columnar structures of a Solodized Solonetz (Typic Natrustalf)-SEM & EDS were used to characterize these features, and to determine their probable pedogenesis. The size range was bimodal in the Red Podzolic B horizon, being either ∼5 μm or ∼2.0 um. In the Solodized Solonetz all tori were ∼ 1.5 μm in diameter. The larger tori consisted of fine-clay coated collapsed fungal spores, whilst the smaller tori were fine-clay coated collapsed bacteria-sized cells.     

Improved prediction of water-retention properties of clayey soils by pedological stratification

The water-retention properties of clayey soils have been studied at ?0.3 × 10⁵ and ?15 × 10⁵ Pa matric potentials using three sets of clayey horizons differing in their pedological origin. Measurements were made on small clods collected in winter when swelling is at a maximum. The results are discussed in relation to variations in the clay content and clay fabric. The bulk volume, which appears to be closely related to both clay content and clay fabric, allows the variations in water retained to be explained better than with clay content alone. With clayey horizons originating from a single soil family, differences in water retained can be explained by variations in clay content alone because clay fabric does not change greatly. These results demonstrate the significance of pedological stratification in estimating the water-retention properties when a single soil characteristic, such as clay content, is used.     

中国亚热带山地土壤发生特性和系统分类研究进展

弄清亚热带地区花岗岩中山土壤发生学属性与土壤类型的垂直地带性分布规律。

选取莽山不同海拔带的8个典型单个土体,野外观测土壤剖面形态,室内测定土壤理化性质,划分土壤类型,在地理发生分类、中国土壤系统分类和国际土壤系统分类之间进行参比。

土体厚度介于18 ~ 180 cm,以山体中部最为浅薄。质地主要为砂质壤土和砂质黏壤土,黏粒含量随海拔升高而降低;山体上部（> 1000 m）土壤B层有腐殖质、黏粒胶膜和黏粒累积形成的黏化层。土壤有机碳和CEC值随海拔升高而升高,但腐殖质层浅薄,多为淡薄表层。这些土壤指标呈垂直地带性,反映了花岗岩中山土壤发生学特性。供试剖面土壤呈酸性,铝饱和度和铁游离度较高,铁质特性与铝质现象普遍,CEC为9.7 ~ 29.1 cmol (+) kg⁻¹,一些土壤发生学属性指标（土壤色调、pH、铁游离度、铝饱和度）无明显垂直地带性。中国土壤系统分类划分出富铁土、淋溶土、雏形土和新成土4个土纲、5个亚纲、6个土类、8个亚类、8个土族和8个土系。

土纲垂直带谱为雏形土、富铁土（400 ~ 700 m）—雏形土、新成土（700 ~ 1200 m）—雏形土、淋溶土（1200 ~ 1800 m）,呈组合、跨带地域分布规律。与土壤地理发生分类相比,土壤系统分类侧重体现更多土壤发生学属性指标,同一海拔带内划分出了更多土壤类型,反映土壤多样性。

     

Colloid-chemical model for describing some soil processes

Arguments are presented for changing the approach to soil studies in order to consider the behavior of soils in terms of a colloid-chemical model rather than in terms of a physical model. Experimental studies of changes in the stickiness of an air-dry chernozem depending on the time elapsed since adding water, of the catalase activity of soils depending on the time elapsed since adding water and salt solutions, of the thermal diffusivity of soils depending on the time elapsed since adding water, and of the soil temperature showed that the soil solution is a structured colloidal system. Electron microscopic studies of soil solutions confirmed that colloidal particles of soil solutions interact with one another due to long-range aggregation to form periodic colloidal structures enclosing soil moisture. It was concluded that the colloidal structuring of the soil solution makes it similar to physiological fluids and makes the soils similar to biological systems; therefore, the consideration of soils in terms of a colloid-chemical model expands our knowledge of these systems and can be useful for soil scientists.     

Using pedological knowledge to improve sediment source apportionment in tropical environments

Journal of Soils and Sediments - Soils are important regulators of Critical Zone processes that influence the development of geochemical signals used for sediment fingerprinting. In this study,...     

The preferential flow of soil: A widespread phenomenon in pedological perspectives

The article provides an overview of studies about the preferential flow phenomenon. This phenomenon is one of the types of the transportation of water solution through the soil profile by preferential channels (pathways) with a relatively high speed and with a slight change in the chemical composition of the solution. Interest in this phenomenon has risen sharply in the last two decades due to the observed fast transportation of contaminants from soil surface into groundwater level. On the basis of the literature data, the authors give the definition of this phenomenon, consider its types, degree, features, mechanisms, methods and models and research perspectives, in particular the interaction between preferential flow and soil matrix flow. The article considers the aspects of the movement of soil water carrying heavy metals and pesticides; hence, it concerns the protection of environment and people’s health. It provides the thorough review of the studies on the preferential flow, and describes the research directions and their development.     

Boron as a transducer in some physiological processes of plants

The physiological role of boron in plants is depicted as that of a transducer in several processes initiated by light, gravity, and some plant hormones. Some studies had shown that these actions of light and gravity depend upon the presence of boron. Boron had been demonstrated to be concentrated in the cell membrane. It is suggested that boron acts by forming a strong, positive electrostatic charge in the membrane through the capture of an electron loosen from a donor (probably a sulfhydryl containing compound) which is perturbed by actions of light, gravity, and phytohormones. The generated positive charge could control the passage of ions through pores of the cell membrane to regulate pinnule movement. The positive charge could also attract and orient negatively charged molecules, such as nucleic acids, and thereby initiate, facilitate, or control certain vital reactions involved in cell division, cell elongation, and flowering.     

Boron as a transducer in some physiological processes of plants

The physiological role of boron in plants is depicted as that of a transducer in several processes initiated by light, gravity, and some plant hormones. Some studies had shown that these actions of light and gravity depend upon the presence of boron. Boron had been demonstrated to be concentrated in the cell membrane. It is suggested that boron acts by forming a strong, positive electrostatic charge in the membrane through the capture of an electron loosened from a donor (probably a sulhydryl containing compound) which is perturbed by actions of light, gravity, and phytohormones. The generated positive charge could control the passage of ions through pores of the cell membrane to regulate pinnule movement. The positive charge could also attract and orient negatively charged molecules, such as nucleic acids, and thereby initiate, faciliate, or control certain vital reactions involved in cell division, cell elongation, and flowering.     

Predicting unsaturated hydraulic conductivity of soil based on some basic soil properties

Soil hydraulic conductivity is a crucial parameter in modeling flow process in soils and deciding water management. In this study, by combining the non-similar media concept (NSMC) to the one-parameter model of Brooks and Corey, a new NSMC-based model for estimating unsaturated hydraulic conductivity of various soils was presented. The main inputs are soil bulk density, particle-size distribution, soil water retention characteristic and saturated hydraulic conductivity of soil. The results indicated that the NSMC-based model could generally more accurately predict unsaturated hydraulic conductivity of soils, as compared to four one-parameter models and van Genuchten–Mualem model. This study, by introducing NSMC, provided a new way to incorporate soil physical heterogeneity into soil hydraulic simulation, and hence NSMC-based approach is expected to improve efficiency of the existing models in the simulation of soil water flow.     

The importance of andic soils in mountain ecosystems: a pedological investigation in Italy

Andic soils have unique morphological, physical and chemical properties that induce both considerable soil fertility and great vulnerability to land degradation. In recent years there have been many reports of soils with andic properties in Non‐Volcanic Mountain Ecosystems (NVME) in different parts of the world. This paper attempts to assess the importance of andic soils in mountain ecosystems of Italy. We used the criteria of altitude (> 700 m above sea level), slope (< 12°) and active green biomass (maximum Normalized Difference Vegetation Index (NVDI) value > 0.5) for identifying sites where andic soil processes may occur in the NVME of Italy. We characterized in detail 42 soils in the areas thus identified. According to WRB (2006) the main soils are Andosols, Cambisols, Phaeozems, Umbrisols and Podzols. Despite the taxonomic diversity, the morphological, micromorphological and chemical properties indicate considerable pedological homogeneity in these soils. The most striking features are the large values of Al_o + 0.5Fe_o (as %), which is a standard index for andic soil properties ( USDA, 2006; WRB, 2006 ), but it occurs at the wrong depths for many of our soils to qualify as true Andosol/Andisols and there is little evidence of podzolization. We therefore suggest that (i) andic soils must be recognized more clearly in soil classification, particularly with respect to the depths at which andic properties are developed, and (ii) the importance of andic soils in Italian NVMEs (and possibly elsewhere in the world) has been underestimated. These soils warrant further investigation because of their agricultural potential and ecological importance.     

Dust rains in Mallorca (Western Mediterranean): Their occurrence and role in some recent geological processes

Dust rains were observed in Palma de Mallorca (Island of Mallorca, Western Mediterranean) on 253 days in the 22-year period from 1982 to 2003. These and other data from the Western Mediterranean show that dust rains are on the increase. Most occur in the warmest season of the year. Meteorological conditions associated with this phenomenon combine hot advection from the south at low tropospheric levels with southwest winds associated with a depression in the middle troposphere. Dry deposition of dust, often in aggregates 40–300 μm across, is occasionally observed. Analysed samples are silty and mainly composed of quartz and kaolinite. They also contain minor proportions of feldspars and palygorskite, which do not occur as rock-forming minerals in the Balearic Islands. Comparisons of the dusty rainwater samples with soils and recent marine and karstic sediments suggest that dust deposition is an important sedimentary process in the Balearic Islands.     

Iron oxyhydroxides in soils developed from Lower Palaeozoic sedimentary rocks in mid-Wales and implications for some pedogenetic processes

Lepidocrocite and goethite are pedogenetic crystalline Fe oxyhydroxides in the soils of mid-Wales. Lepidocrocite is more abundant and widespread, occurring in brown earths (Denbigh series) as well as morphological gleys. It is commonly dominant in horizons intermediate in depth. Goethite occurs in subsoils and was found to be dominant in the subsoil of surface water gleys (Cegin series). Apart from the Cegin series, a large proportion of the total free Fe occurs in non-crystalline forms. This amounted to 50–80% of the free Fe in organic and eluvial horizons of podzols. Despite lower proportions of non-crystalline Fe in Bs horizons, amounts were similar to those in eluvial horizons. Data on the distribution of crystalline and non-crystalline free Fe together with correlations observed between Fe and C extracted by pyrophosphate suggest that transformation and translocation of Fe in the podzols examined are governed by its association with organic fractions.     

基于基流比例法的渭河生态基流计算

为使生态基流更好地体现中国北方河流生物需水的年际间和年内变化,该文提出基流比例法。将长期径流系列资料划分为丰、平、枯及特枯年等不同年型,采用传统方法确定某一年型的基流比例后,通过该年型与其他各年型平均径流量之间的比值,推求出基流比例之间的关系,由此计算出其他各年型的基流比例及生态基流值。根据需要,还可进一步将年内划分为不同时段分别计算。以渭河干流宝鸡段为例,应用该方法计算了各年型及年内各时段的生态基流值,其结果为5.02～36.73 m3/s,比较后发现其他几种常见方法计算的生态基流值均在该范围之内,各代表年基流的保障程度基本都能达到90%以上,但是近几年呈现递减的趋势。该方法适合中国北方河流生态基流的计算。     

A pedological investigation of an archaeological site in Ontario,Canada, I. An examination of the soils in and adjacent to a former village

The Benson site is a former village which was inhabited by Huron Indians in the 1600's. It is located 90 km northeast of Toronto, Canada. The soils of a portion of the site were sampled on a 1-m grid 15 cm below the surface. These soils were then analyzed for magnesium, calcium, potassium, sodium, phosphorus, carbonates, pH and organic carbon. Three off-site soil profiles (Podzols) were sampled and analyzed for comparative purposes.Of the chemical attributes of soil materials studied at the Benson site amounts of magnesium, organic phosphorus, and inorganic phosphorus were sufficiently different to be useful in distinguishing formerly occupied soils from off-site soils. Such information may thus be an aid to archaeologists in determining the presence or absence of sites occupied in the past.     

Effect of freezing and thawing processes on some physical properties of saline–sodic soils mixed with sewage sludge or fly ash

Dispersion of saline–sodic soils was rather difficult to leach. Therefore, negative effects of freeze–thaw on soil physical properties should be reduced by inexpensive and practical methods. This study investigates the effect of freeze–thaw cycles (3, 6, and 9) on wet aggregate stability, bulk density, and permeability coefficient in three soils with different electrical conductivity and exchangeable sodium percentage levels (soil I: 5.30 dS m⁻¹, 47.51%; soil II: 42.80 dS m⁻¹, 55.45%; soil III: 36.30 dS m⁻¹, 59.34%) which consist of different proportions of sewage sludge and fly ash by volume (10%, 20%, and 30%). The experiment was conducted under laboratory conditions using disturbed and non-cropped soil samples mixed with sewage sludge and fly ash. Soils mixed with sewage sludge produced higher aggregate stability and permeability coefficients and lower bulk density values as compared to the soils mixed with fly ash. Sewage sludge added with a rate of 30% eliminated the negative effects of freeze–thaw processes on wet aggregate stability. Freeze–thaw processes did not affect the bulk density of the soils II and III, which were mixed with sewage sludge. However, fly ash addition decreased the bulk density of these soils very significantly after nine freeze–thaw cycles. Addition of sewage sludge or fly ash with rates of 20% and 30% significantly increased the permeability coefficients in soil I after nine freeze–thaw cycles. Results indicated that addition of sewage sludge and/or fly ash to saline–sodic soils could be alternative way for reducing negative effects of freezing–thawing on soil wet aggregate stability, bulk density, and permeability coefficient.     

电子支付工具基本问题探讨

在数字化的交易环境中,因网络之发达,使得网络上之商业行为具有很强的开放性,没有空间和时间的限制,而这些商业行为均须依赖一个可令人信任及有效率之付款方式来拓展。因此,国际社会已开始高度重视电子付款制度及其安全问题。本文拟通过电子支付工具定义、电子支付工具的发展、电子支付工具的类型及目前所面临的多重问题几个方面,探讨电子支付工具的相关问题。指出电子银行共享网络系统的建立,使电子支付已经不再局限于简单的银行与客户之间的关系,而表现为涉及到多重主体之间的复杂关系。构建电子支付工具体系,必须考虑多重主体之间关系的厘清、并重视网络信息技术的完善和网络安全的保障。