豫中黄土地区全新世黄土剖面成壤作用与古气候研究

通过对河南豫中黄土地区黄土剖面化学元素的深入研究认为:在该地区全新世中期风化成壤过程中,Al、Fe、K、Ti、Rb、Ba等元素在古土壤中相对富集,表现出残留富集的特征;而Si、Ca、Na、Sr等元素则在风化剖面中淋失。而Al、Na在成壤过程中因具有不同的地球化学行为,从而产生显著的分异现象,并且随着成壤作用的增强分异加剧。因此,Al/Na值在黄土剖面中的变化反映了风尘堆积物成壤强度的变化,能够作为成壤作用、气候变化的替代指标。     

雷州半岛玄武岩母质土壤剖面稀土元素分布及其与常量元素、粒度的关系

对雷州半岛玄武岩母质土壤剖面稀土元素地球化学特征进行了研究,结果表明:土壤剖面中稀土元素的分布既受母岩的控制,又叠加了风化成壤作用的影响,∑REE和δEu对母岩有明显的继承性,风化成壤作用则导致REE在剖面上部富集以及土壤中Ce的显著正异常,并造成轻、重稀土之间发生一定的分馏(以轻稀土富集为主要特征),但轻稀土或重稀土内部未出现明显的分异;∑REE与Fe2O3含量呈极显著负相关,可能与风化成土过程中铁氧化物结晶程度提高,富含REE的无定形铁含量降低有关;∑REE与P2O5、MnO则呈极显著正相关,应当是由于剖面中含有较多的赋存REE的磷酸盐矿物和锰氧化物矿物所致;∑REE与黏粒组分(尤其是<1μm的组分)呈极显著正相关,表明风化成壤过程中黏土矿物含量增加所导致的对REE的吸附效应是造成该区REE富集的重要原因,其中黏粒对轻稀土元素的吸附更为明显。     

淮河上游全新世黄土-古土壤序列元素地球化学特性研究

在野外考察研究的基础上,对河南禹州全新世风成黄土-古土壤剖面系统采样,利用X-荧光光谱仪测定了常量元素和微量元素的含量及其变化,并与磁化率曲线、粒度变化曲线对比分析发现:常量元素氧化物比值钾钠比、残积系数和以Rb为代表的微量元素含量等随剖面层次呈规律性变化,即在古土壤层(S0)中含量最高,表土层(MS)中次之,在黄土层(L1、Lt、L0)中最低。硅铝率和Sr的含量表现出相反的变化规律。表明在全新世古土壤层和表土层形成时期,气候温暖湿润,成壤作用和次生粘化作用较强;在黄土堆积时期,气候比较干旱,沙尘暴频繁,成壤作用微弱。这些化学参数与磁化率曲线可以进行对比,表明成土过程中元素的迁移变化受全新世以来气候变化和成壤环境变化的控制。与黄土高原腹地的洛川剖面相比,淮河上游禹州剖面中绝大多数常量元素的含量较高,而绝大多数微量元素的含量偏低,磁化率也显著偏低,绝对值差别很大,粒度组成当中细沙成分含量很高,这说明淮河上游黄土物质来源与黄土高原地区明显不同。联系全新世时期黄河频繁泛滥、改道、沉积与黄淮平原盛行东北风形成流沙地的事实,认为淮河上游的黄土是黄河泛滥沉积物质经过风沙活动改造,由东北风力系统搬运而来的近源粉尘堆积,再经过就地风化或者成土改造而形成。     

丹江中游河谷黄土母质发育土壤的诊断特征及其系统分类研究

选择位于河南省南阳市淅川县荆紫关镇龙泉村丹江中游河谷黄土母质发育的土壤剖面作为研究对象,对其剖面构型及其色度、元素、粒度等理化性质进行了分析。结果表明,丹江中游河谷黄土母质发育的土壤具有Ap-Bp-Bt-Bw剖面形态特征;在剖面40~220 cm深度发生明显的黏粒富集,具有黏化层(Bt)的诊断特征;风化成壤强度达到中等风化强度阶段。剖面具有热性土壤温度状况和湿润土壤水分状况,在中国土壤系统分类中可划为耕淀简育湿润淋溶土。     

末次间冰期-冰期旋回黄土环境敏感粒度组分的提取及意义

采用粒级-标准偏差方法对黄土高原西部、河西走廊及河南西部等6个剖面末次间冰期-冰期旋回的黄土-古土壤粒度进行了系统分析，提取了对环境变化敏感的粒度组分。各剖面的环境敏感粒度组分主要分为粗细两个组分，并显示出一定的区域性差异和不同的沉积学意义。敏感组分主要受物源和沉积后成壤作用的影响：冰沟和罗家湾剖面可能受源区的影响更大而使敏感组分偏粗，暖和湾和扣马剖面可能由于后期风化的影响较大而使敏感组分偏细。对扣马剖面末次冰期旋回堆积的L1和S1的粒级一标准偏差分析表明，L1的敏感组分与全剖面相似；而S1的敏感组分与全剖面存在较大差异，可能与成壤作用有关。     

海南岛北部玄武岩区土壤母质均一性及相对年龄判定

【目的】时间序列法是定量研究土壤发生过程、演变速率及其变化阈值的重要手段,构建可靠的土壤时间序列需对土壤母质均一性和相对年龄进行判定。【方法】以海南岛北部不同喷发期玄武岩发育土壤所构成的成土时间序列（0.09、0.146、0.64、1.12、1.81、2.30 Ma B. P.）为对象,利用各种土壤属性参数（包括剖面形态、颗粒组成、稳定元素含量、风化发育指数和元素变化率等）对该时间序列母质均一性和土壤相对年龄进行判定。【结果】各剖面颜色、质地、结构等形态总体呈均一、渐变的特征,去除黏粒后的粗粉粒含量、稳定元素Ti/Zr比值在剖面内和剖面间变化均较小,表明时间序列土壤的起源母质相同。随着成土年龄的增加,黏粒含量和剖面发育指数呈线性增加的趋势,土壤风化强度指标（B指数、CIW指数、CIA指数和ba值）服从对数函数变化规律,在土壤相对年龄的判定中具有较好的指示意义。【结论】研究区土壤母质来源相同,土壤相对年龄可通过相关土壤属性体现出来,为定量研究土壤发生阈值奠定了基础。     

关中盆地全新世黄土-土壤剖面微量元素的地球化学特征及其古气候意义

通过对老官台全新世黄土剖面12种微量元素的测定分析,结合本剖面已测定的粒度、磁化率、光释光(OSL)年龄,研究和揭示了它们在表生环境下的地球化学特征和古气候意义。微量元素在风化成壤过程中,其活动性由强至弱顺序为BaSrCdPbLiZnCuCrMnCoRbNi。其中Rb、Li、Cr、Co、Zn、Cu、Mn、Ni八种元素在土壤形成过程中相对富集,含量较高;Sr、Ba、Cd三种元素在土壤中相对淋失,含量较低;但Zn、Cu、Mn、Ni、Pb五种元素对黄土层和土壤层的区别不是很明显。因此,Rb、Li、Cr、Co的高含量反映了较温湿的成壤环境,低含量反映了较冷干的粉尘加积环境;而Sr、Ba、Cd低含量反映了较温湿的成壤环境,高含量反映了较冷干的粉尘加积环境。Pb、Zn、Cu、Mn、Ni、Cd元素含量在表土层中的富集主要与现代耕作活动或工业污染有关,反映了人类活动强度的不断增强。LGT剖面主要微量元素的变化清楚地记录了关中盆地自末次冰消期以来气候环境经历的显著波动变化。     

母质对南方丘陵区水耕人为土理化性质演变的影响

基于时间序列系统分析了我国南方丘陵区三种母质起源的水耕人为土理化性质的演变,结果表明:成土母质可以决定黏粒与土壤有机碳(SOC)对人为水耕成土过程的敏感性,明显影响其演变特征。游离铁(Fed)对人为水耕的成土过程非常敏感,其迁移与转化主要受人为水耕成土过程影响,受成土母质影响很小;硅酸盐铁(Fet-Fed)对人为水耕的成土过程不敏感,但全铁(Fet)含量的分布主要受Fed的影响。黏粒的淋失会对土壤中元素的迁移与分布产生重要影响,造成SiO2相对富集和Al2O3相对亏损,在利用由Al和Si两种元素计算所得到的一些指标指示丘陵区水耕人为土的发育程度时一定要慎重;而TiO2在水耕人为土发育过程中相对稳定,可以作为稳定元素来指示水耕人为土演变过程中其他元素的迁移率。     

鼎湖山土壤有机质深度分布的剖面演化机制

根据鼎湖山森林植被带(SL)、灌丛—草甸过渡带土壤剖面(GC)有机质含量,有机质Δ14C、δ13C值,土壤粘粒含量及孢粉分析结果,研究华南亚热带山地土壤有机质深度分布特征的成因机制。结果表明土壤有机质的深度分布特征与土壤剖面的发育过程密切相关,随深度增大,有机质的来源数量不断减少,而成土时间增加,分解作用导致的有机质含量降低幅度增大,有机质含量不断减少。土壤有机质14C表观年龄随深度增加,土壤有机质δ13C值与有机质含量的深度变化具有明显对应关系,这些都是土壤剖面发育过程中有机质不同更新周期组分呈规律性分解的结果。粘粒的深度分布反映土壤剖面淋滤淀积的特点,表明土壤剖面经受了长期成土风化。土壤剖面的上述特征均为剖面发育过程中不断沉积、不断成土的结果,表明土壤剖面成土演化对于有机质深度分布具有显著制约。     

海南砖红壤的微形态特征以及南方网纹红土与砖红壤环境意义的差异

主要运用土壤微形态学、粘土矿物学和土壤化学方法,对海南岛三个不同母质的砖红壤剖面的微形态特征和成壤过程进行研究,并将网纹红土和砖红壤进行比较.结果表明,砖红壤典型的微形态特征为易风化矿物颗粒和粘粒胶膜的缺失、均质状的b-垒结以及风化成因铁锰质结核的出现;典型的成壤过程为强烈的化学风化、红化、均质化、淋溶以及显著的脱硅富铝化过程.随着成土母质和土壤排水条件的变化,砖红壤的微形态特征亦有所差异.而我国南方的网纹红土的发育程度低于砖红壤,不宜被划分为砖红壤或氧化土,而更趋向归入老成土,在我国土壤发生学分类中大致相当于红壤.     

The ages and soils of two levels of “raña” surfaces in Central Spain

The geomorphology of two rañas and a specimen soil profile on each have been studied in the Province of Guadalajara, Central Spain. The rañas were first delineated on an aerial photograph, then examined in the field for further identification and for the preparation of topographic profiles. Two soil profiles were described and sampled by horizons. Analyses were made of the samples for particle size distribution, pH, cation exchange relations and organic matter plus some observations on mineralogy of clay and fine sand fractions. Results of the study support earlier suggestions that the younger rañ asurface (S-1) is of Donau age (Middle Villafranchian) but indicate that the second (S-2) should be assigned to the Middle-Upper Pliocene (Lower Villafranchian). The soil profiles were found to be an Alfisol on the younger and an Ultisol on the older raña which is consistent with a greater age for the latter.     

Genesis and age of mineralogical profiles of Moldavian chernozems

In chernozems developed in the autonomous positions in Moldova, the mineralogy of their silicate component has some features indicative of stronger transformations than those that could be expected for the chernozems formed by the Holocene pedogenesis. The mineralogical profiles testify to the eluvial nature of the main subtypes of chernozems. It is suggested that the revealed changes are not due to the Holocene pedogenesis. According to the probable age of the mineralogical profiles calculated from the volumes of aluminosilicates removed, these profiles originated in the early and middle Late Pleistocene, i.e., about 50 000–120 000 years ago. The effect of forest pedogenesis in the past epochs on the mineralogy of the northern subtypes of chernozems also cannot be excluded. The presented data characterize the chernozems under study as polygenetic soil formations.     

Silicon pools and fluxes in soils and landscapes—a review

Silicon (Si) is the second‐most abundant element in the earth's crust. In the pedosphere, however, huge spans of Si contents occur mainly caused by Si redistribution in soil profiles and landscapes. Here, we summarize the current knowledge on the different pools and fluxes of Si in soils and terrestrial biogeosystems. Weathering and subsequent release of soluble Si may lead to (1) secondarily bound Si in newly formed Al silicates, (2) amorphous silica precipitation on surfaces of other minerals, (3) plant uptake, formation of phytogenic Si, and subsequent retranslocation to soils, (4) translocation within soil profiles and formation of new horizons, or (5) translocation out of soils (desilication). The research carried out hitherto focused on the participation of Si in weathering processes, especially in clay neoformation, buffering mechanisms for acids in soils or chemical denudation of landscapes. There are, however, only few investigations on the characteristics and controls of the low‐crystalline, almost pure silica compounds formed during pedogenesis. Further, there is strong demand to improve the knowledge of (micro)biological and rhizosphere processes contributing to Si mobilization, plant uptake, and formation of phytogenic Si in plants, and release due to microbial decomposition. The contribution of the biogenic Si sources to Si redistribution within soil profiles and desilication remains unknown concerning the pools, rates, processes, and driving forces. Comprehensive studies considering soil hydrological, chemical, and biological processes as well as their interactions at the scale of pedons and landscapes are necessary to make up and model the Si balance and to couple terrestrial processes with Si cycle of limnic, fluvial, or marine biogeosystems.     

Silicon pools and fluxes in soils and landscapes—a review

Silicon (Si) is the second‐most abundant element in the earth's crust. In the pedosphere, however, huge spans of Si contents occur mainly caused by Si redistribution in soil profiles and landscapes. Here, we summarize the current knowledge on the different pools and fluxes of Si in soils and terrestrial biogeosystems. Weathering and subsequent release of soluble Si may lead to (1) secondarily bound Si in newly formed Al silicates, (2) amorphous silica precipitation on surfaces of other minerals, (3) plant uptake, formation of phytogenic Si, and subsequent retranslocation to soils, (4) translocation within soil profiles and formation of new horizons, or (5) translocation out of soils (desilication). The research carried out hitherto focused on the participation of Si in weathering processes, especially in clay neoformation, buffering mechanisms for acids in soils or chemical denudation of landscapes. There are, however, only few investigations on the characteristics and controls of the low‐crystalline, almost pure silica compounds formed during pedogenesis. Further, there is strong demand to improve the knowledge of (micro)biological and rhizosphere processes contributing to Si mobilization, plant uptake, and formation of phytogenic Si in plants, and release due to microbial decomposition. The contribution of the biogenic Si sources to Si redistribution within soil profiles and desilication remains unknown concerning the pools, rates, processes, and driving forces. Comprehensive studies considering soil hydrological, chemical, and biological processes as well as their interactions at the scale of pedons and landscapes are necessary to make up and model the Si balance and to couple terrestrial processes with Si cycle of limnic, fluvial, or marine biogeosystems.     

The origin of sulfate salts in soils developed on Maikop clays in the North Caucasus region (According to data of the isotope composition of sulfur)

The ratio of ³²S/³⁴S stable isotopes was determined for soils developed on the Maikop clay sediments in the North Caucasus region in order to study the salt geochemistry in the soils. The soil sulfates were proved to be polygenetic. Three groups (generations) of sulfates of different geneses were distinguished according to their isotopic composition (³⁴S). In the underlying deposits and, partially, in the salt-bearing horizons of the soils, secondary sulfates originated from the oxidation of sulfides contained in the marine clay predominate. In the soil profiles, the sulfates inherited from the parent material (marine clay) are mixed with sulfates arriving with the atmospheric precipitation. The portion of the latter reaches about 30% of the total amount of sulfates in the soils. The salt (gypsum)-bearing horizons were formed in the course of the eluvial-illuvial redistribution of salts to the depth of seasonal wetting. The mobilization of sulfate salts from the underlying deposits and their transport to the upper parts of the soil profile with ascending water flows in the course of evaporation from the soil surface did not play a significant role in the accumulation of sulfates in the studied soils.     

MINERALOGY, GENESIS AND CLASSIFICATION OF FERRUGINOUS SOILS OF THE EASTERN MYSORE PLATEAU, INDIA

The relationship of geomorphic and climatic history and formation of the ferruginous soils, formed on the acidic Peninsular Gneiss, of the Mysore Plateau, India, is discussed. The profiles studied are found on two different land systems. The soils of the older, fairly smooth landscape are composed of colluvium over truncated laterite profiles, with a gravel layer and a prominent kaolin layer over the weathered rock. These soils show an accumulation of pedogenic haematite grains in the sand fraction and have considerable kaolinite and amorphous ferri-aluminosilicate minerals in the clays. The soils of the younger, rugged landscape have similar clay mineralogy, but do not have a gravel layer, or haematite grains. The influence of the coarse-grained parent rock is seen in the large amounts of quartz gravel. The absence of granulation is attributed to lack of accumulation of iron. The soils have been formed in an earlier, more humid climate than prevails today. The original laterite profiles were formed on a plane surface, and subsequent change in climate has led to change in the land forms and dissection. Truncation of the profiles was followed by deposition of red colluvium over the resistant ferruginous layer. These ancient soils do not fit the criteria for Oxisols in the U.S. classification, but fit well in the French system as ‘Sols Ferrallitiques’, subclass ‘fiablement désatures en (B)’. The soil from a low lying area, formed from colluvium under hydromorphic conditions. is classified as‘Vertisols et Paravertisols'.     

不同耕作年限水稻土土壤颗粒的体积分形特征研究

应用基于土壤颗粒体积分布确定土壤颗粒大小分布分形维数的方法,对浙江慈溪耕作年限分别为50、100、500、700、1000和2000年的水稻土土壤颗粒体积分形特征进行了研究.结果表明:同基于土壤颗粒质量分布的分形维数相比,基于土壤颗粒体积分布的分形维数计算不需要密度假设,更具有合理性.不同年限水稻土的土壤颗粒大小分布能被体积分形模型显著拟合(p＜0.01).土壤颗粒体积分形维数与黏粒的体积百分含量之间呈显著正相关(p＜0.01),与粉粒和砂粒的体积百分含量之间呈显著负相关(p＜0.01),其中与黏粒含量关系最为密切.耕作年限对水稻土土壤颗粒的体积分形维数和分形模型的拟合度均有一定影响.与50 ～ 500年水稻土相比,700 ～ 2000年水稻土剖面中土壤颗粒体积分形维数的变异性和均值较高,但其拟合决定系数则较低;耕作年限会对水稻土剖面中黏粒的含量和分布产生影响,进而影响到剖面土壤的颗粒体积分形特征;对于同一质地类型的土壤,耕作年限越长,分形维数越高.     

Diffusion‐controlled mobilization of water‐dispersible colloids from three German silt loam topsoils: effect of temperature

The effects of time and temperature on the release kinetics of water‐dispersible colloids (WDCs) from three German silt loam topsoils in deionized water were investigated in batch experiments under low‐energy rotating shaking conditions. The measured critical coagulation concentrations of Ca²⁺ and Na⁺ for extracted WDC were much larger than the experimental ionic conditions. This indicates a fast dispersion rate in the first detachment step of WDC mobilization from soil aggregates. The cumulative released WDC fraction F(t) (released WDC/clay content in bulk soil) was satisfactorily fitted to the square root of shaking time by a linear function in three soils with a similar clay content. This implies diffusion‐controlled release kinetics in the second step of the WDC mobilization process. The mobilization kinetics were modelled by considering a diffusion‐controlled transport through an immobile water layer in the macropores of soil aggregates formed by silt and sand particles. The effects of temperature on the mobilization kinetics and sedimentation volumes of saturated soils were compared at 7, 23 and 35°C. A linear correlation was found between immobile water layer thickness in soil macropores (l_t) and the water volume (V_water) in soil sediment, which indicates a strong dependence of l_t on the soil texture. Temperature‐sensitive l_t and V_water influenced the effect of temperature on WDC release, which counteracts the estimated effect of temperature on particle diffusion according to the Stokes‐Einstein relation. A larger decrease in F(t) was found in grassland and forest soils than in an arable soil and can be related to greater stagnant water contents (larger l_t and V_water) in soil macropores, where particulate organic matter and polyvalent cations in their oxide forms at acidic pH will thus contribute to water immobilization.     

面向土壤系统分类的土壤调查制图方法的初步研究

我国的土壤系统分类方案已经基本形成,但还没有相应的土壤调查方法技术研究。按照传统土壤调查的主要剖面、检查剖面、定界剖面的思想与办法,采用空间内插技术,在研究区的4条实验路线上共挖掘了64个剖面点,通过这些剖面点的诊断层和诊断特性确定了研究区的土壤类型并勾绘了土壤类型界线。再用1条检验路线对勾绘的土壤图进行检查,结果表明,在检验路线上设置的20个检查剖面点中,其中19个剖面点与实际情况相符,正确率95%,说明使用内插法进行面向土壤系统分类的土壤调查制图是可行的。再结合土壤景观可以辅助土壤调查工作者更高效地确定土壤类型、勾绘土壤界线。