不同水肥处理下冬小麦冠层含水率与温度关系的研究

研究了不同水肥处理下冬小麦冠层含水率与冠层温度的关系。结果表明,随灌水量增加,冬小麦冠层含水率呈逐渐增加的趋势,灌水量达一定程度后,冠层含水率反而下降,冠层温度表现出与冠层含水率相反的趋势;冠层含水率与冠层温度呈显著负相关。两品种施氮处理冠层含水率均明显高于不施氮处理。“京冬8号”各施氮处理冠层含水率随施氮量增加呈逐渐降低的趋势,冠层温度则随施氮量增加而上升;其冠层含水率与冠层温度存在显著负相关关系。“中优9507”各施氮处理不具“京冬8号”的规律性,但其冠层含水率与冠层温度也呈负相关。用冠层温度反映冠层含水率具有较高的可靠性。     

中国正常干旱土亚纲的系统分类

本文按照《中国土壤系统分类（首次方案）》，首先以盐积层、碱积层等检索出盐成土，将难于改良的盐土和碱土完全集中起来，然后用新建立的干旱土表层和干旱土特有的诊断表下层检索出干旱上。并根据钙积层、石膏层、盐积层、粘化层以及雏形层等诊断层，按此顺序检索正常干旱土亚纲各土类，基本上与原半荒漠土壤和棕漠土、灰漠土等主要土类相对应。文中列举各主要亚类的理化分析结果，并对干旱土诊断层和诊断特征概念和指标作了较明确     

乔灌草植被条件下土壤水分动态特征

以16年的定位土壤水分实测资料为基础，对乔灌草植被条件下土壤含水量的年度、季节及垂直动态特征进行了研究，结果显示：在0～100cm和0～500cm深度上，草地土壤水分含量大于乔木和灌木；生长盛期乔木和灌林土壤含水量较低，草地变化不大。土壤垂直动态分析表明：乔木、灌木和草地土壤水分按照速变层、活跃层、次活跃层和相对稳定层划分，其位置和排列顺序都不尽相同，荒草地0～60cm为速变层，依次再往下60～280，280～400，400～500cm分别是活跃层、次活跃层和相对稳定层；山桃林0～40，40～240，240～400，400～500cm分别是速变层、相对稳定层、次活跃层和活跃层；柠条林0～80，80～220，220～320，320～500cm分别是速变层、活跃层、相对稳定层和次活跃层；土壤干层在3种植被条件下都有存在，但以乔木垂直范围最广，历时最长，灌木次之，草地再次之，草地植被随深度下降，其水分波动越来越小；乔木土壤表层水分变化剧烈，但到100cm左右水分变化程度较小，再往下，变化又趋剧烈；灌木与乔木相似，但变化程度不及乔木强烈。     

黄土高原土壤干层研究述评

从土壤干层的定义及土壤干层形成的气候、土壤、植被和人为因素等4个方面综述了黄土高原土壤干层研究的现状和问题,并指出了需要进一步加强的研究领域.     

林分枯落物持水能力研究

枯落物层是森林结构中重要的组成部分,在森林生态系统中发挥着水源涵养与水土保持的作用。通过对不同林分未分解枯落物层和半分解枯落物层0.5 h、1 h、3 h、5 h和24 h持水量的分析比较,发现各林分未分解枯落物层24 h最大持水量从大到小依次为忍冬(51.95 g)、杜仲(40.64 g)、樟子松(39.98 g)和油松(39.81 g);各林分半分解枯落物层持水量从大到小依次为油松(32.84 g)、樟子松(26.94 g)、杜仲(25.58 g)和忍冬(23.07 g);未分解枯落物层持水量皆大于半分解枯落物层持水量;不同林分各时段两层枯落物总持水能力从大到小依次为忍冬、油松、樟子松和杜仲。     

冬小麦冠层温度及其影响因素探析

采用涡度相关法测定冬小麦农田潜热通量和显热通量 ,研究农田热量平衡各分量及风速对冠层温度和冠层 大气温差的影响结果表明 ,净辐射通量是影响冠层温度高低的主要能量因子 ,二者呈极显著线性相关关系 (α =0 .0 1) ,潜热通量、显热通量和土壤热通量对冠层温度的影响与天气状况有关 ,风速变化对冠层温度的影响作用不显著 ,而与冠层 大气温差间有较好的负相关关系     

植物冠层分析仪测定荆条孤立冠层叶面积指数和透光率的分析

利用LAI-2200植物冠层分析仪(PCA)无损测定分析8株荆条(Vitex negundo L.)冠层叶面积指数LAIPCA(3.5~6.5)和天空开度(DIFN),通过LI-200SA传感器同步测定相应的光强透射率τ;同时利用收获法实测荆条冠层叶面积指数LAI收获法,对比分析LAIPCA与LAI收获法、DIFN与τ的相关性和偏差。结果表明:(1)两种方法所测叶面积指数相关极显著(P0.01);LAIPCA比LAI收获法平均偏高2.57%,表明LAI-2200用于荆条灌丛冠层叶面积指数LAI的测定结果偏差较小。(2)LAI-2200PCA测定DIFN与辐射传感器测定冠层透光率τ相关极显著(P0.01),说明LAI-2200 PCA可以替代收获法无损测定荆条孤立灌丛冠层叶面积指数和透光率。本文实现了用冠层分析仪对植物孤立冠层的分析,为林业生产和研究中较为普遍存在的孤立植物冠层下光照分析和叶面积指数测定提供了简便方法。     

塔里木盆地盐渍土开发中搬运盐聚层问题的研究

在塔里木盆地，高盐分含量的盐渍土是主要的宜农后备土地资源．对搬运盐聚层的可行性分析表明，它有盐聚层厚度不大、存在堆积盐聚层的土地、　大量的盐分被搬运等有利条件．搬运盐聚层进行盐渍化治理的主要优势是降低了洗盐用水量　、部分盐分直接脱离了洗盐脱盐循环、削弱了对河水的污染．     

基于冠层上下部温差的冠层阻力计算

为了研究交替隔沟非充分供水下玉米冠层阻力的计算方法,于2009—2010年在中国农业科学院农田灌溉研究所作物需水量试验场进行了田间试验.根据实测资料分析了玉米气孔阻力与各环境因素的关系,基于 Jarvis (1976)多因子冠层阻力模型,引入冠层上、下部温差变量(ΔTc),提出了交替隔沟非充分供水下玉米冠层阻力的计算方法,即基于ΔTc的冠层阻力法,并分别与Jarvis(1976)、Ortega-Farias(2004)和Brisson et al(1998)法作对比研究,验证其准确性.结果表明,Javias(1976)、Ortega-Farias(2004)、基于ΔTc的冠层阻力法和Brisson (1998)的日平均冠层阻力计算结果分别为355.93、318.75、300.61和253.42 sm-1.其中,Ortega-Farias(2004)法和Javias(1976)法模拟结果分别偏高9.70%和22.50%;Brisson(1998)法模拟结果偏低12.78%;基于ΔTc的冠层阻力法计算结果比实测值偏高3.46%,二者的相关性最好,其计算结果与实测值间的平均绝对误差(MAE)、标准差(SD)和拟合度(d1)值分别为2.42、6.77和0.89,R2为0.86,计算精度优于Jarvis(1976)、Ortega-Farias (2004)和Brisson et al(1998)模型.基于冠层上、下部温差的冠层阻力计算法,考虑了作物、土壤、气候3大因素,模型的模拟范围、数据获取和精度都优于其他方法,能够较准确地表达交替隔沟非充分供水下的玉米冠层阻力.     

吴旗县不同植被类型土壤干层特征分析

吴旗县位于黄土高原暖温带半干旱地区,由于降雨量较少以及地表的蒸发和植物的蒸腾,使土壤水亏损严重,部分植被下的土壤中出现了土壤干层。为了系统比较不同植被类型下土壤干层特点,通过对吴旗不同植被0～9.0m土壤水分的实地测量和分析,得出以下结论:除农地外,其它植被类型下都不同程度的存在着土壤干层,干层严重程度,林地大于灌木林地,灌木林地大于草地;草地存在临时干层和永久干层,永久干层深度可以达到4.0m。测量当时,灌木林没有临时干层,存在永久干层,深度3.0～8.4m;杏树林不存在临时干层,油松林临时干层则很严重,杏树林和油松林永久干层深度分别在8.0m和9.0m以上。临时干层的出现取决于降水的补充,因此可能与采样时间有关。通过对吴旗县土壤干层的分析可以为进一步研究土壤干层和植被建设提供借鉴。     

黄土高原塿土覆盖层与黏化层的土壤水文效应

黄土高原(土娄)土在《中国土壤系统分类(修订方案)》中属土垫旱耕人为土类的相应亚类,其土壤水分状况是诊断表层所属人为表层类堆垫表层(覆盖层)和诊断表下层(黏化层)的重要诊断特征。以土壤持水性能、蒸发性能和水分移动性能为切入点,对(土娄)土覆盖层和黏化层的土壤水文效应进行研究论证,以期对土垫旱耕人为土类及其亚类的诊断层与诊断特征获取更深层的认识。     

Proposed revisions to the diagnostic critera for andic and vitric horizons and qualifiers of ardosols in the world reference base for soil resources

World Reference Base for Soil Resources (WRB) was published in 1998 and has begun to be used all over the world. We examined the definitions of andic and vitric horizons and qualifiers (lower-level units) of Andosols in the WRB by using the Tohoku University World Andosol Database (TUWAD) and proposed several revisions. Among 5 items of the definition for the andic horizon, we considered that the requirements of clay and volcanic glass contents should be deleted due to the difficulty in their accurate determination with the progression of soil weathering. In relation to this revision, correction of vitric horizon was also proposed. Although two major types of andic horizons, silandic and aluandic, are specified in the andic horizon definition, the aluandic type is not included in the qualifiers. Because aluandic volcanic ash soils have unique properties and are extensively distributed, the aluandic qualifier should be included in the lower level units of Andosols. Soil texture is used for the definition of arenic, luvic and vatic qualifiers. Therefore, these qualifiers should be modified or deleted. Both melanic and fulvic qualifiers are required to obtain the Munsell color value (moist) and chroma of 2 or less. To distinguish fulvic Andosols from melanic Andosols, the Munsell color and melanic index requirements for a fulvic horizon should be modified. Since Andosols with buried non-Andosols occur in a significantly large area, the thaptic qualifier should be used.     

Pore morphology characteristics of vesicular horizons in undisturbed and disturbed arid soils; implications for arid land management

We compared the pore morphology of an arid lands vesicular soil horizon in a disturbed and undisturbed state. This surface vesicular horizon is characterized by non-connected pores that hinder soil water infiltration and thus plays a central role in arid ecosystem hydrodynamics. Disturbance is hypothesized to result in a change in pore morphology that could alter water movement through the horizon and potentially affect ecosystem function. To test this hypothesis, we examined the pore morphology of the vesicular horizon as expressed in area, perimeter, length and width; comparisons were also made for particle size, pH, calcium carbonate equivalent (CCE), electrical conductivity (EC) and the abundance and types of pores in undisturbed soils and adjacent disturbed soils within a year of disturbance. The results indicate no significant differences between treatments in chemistry, particle size or pore morphological measures within a year following disturbance. Vesicles, vughs and interstitial pores were found in vesicular horizons in both treatments and no significant differences in these parameters were found between treatments. Vesicular horizon development may be related to the geological age of the surface materials. Certain old land surfaces are perhaps more susceptible to the formation of vesicular horizons regardless of disturbance. The results suggest that soil functions dependent upon vesicular porosity, for example hydraulic conductivity, may return to a pre-disturbance condition within one year of disturbance, a finding of importance to the management of arid lands.     

东北典型黑土耕层颗粒组成与腐殖质层厚度的关系

土壤颗粒组成是影响土壤肥力的主要物理性质之一.为了了解东北黑土腐殖质层厚度与土壤颗粒组成的关系,通过在东北典型黑土区选择典型坡面,调查不同地貌部位土壤腐殖质层厚度,测定耕层土壤的颗粒组成,分析腐殖质层厚度和耕层土壤颗粒组成随地貌部位的变化趋势,以及土壤颗粒组成与腐殖质层厚度的关系.结果表明:土壤腐殖质层厚度由上坡至坡脚...     

Characteristics of brown forest soils developed on the paleozoic shale in northern Kyoto with special reference to their pedogenetic process

Abstract

Morphological and chemical properties of brown forest soils and podzolic soils developed on paleozoic shale under beech and/or cryptomeria have been studied with special reference to the eluviation-illuviation characteristics of Fe and Al.

Mobilization of Al was observed even in brown forest soils and its pattern was similar to that in podzolic soils. Its intensity was higher in the brown forest soils developed on the ridge under cryptomeria than in those on the slope under beech. Hence, podzolization is considered to be one of the genetic processes involved in the brown forest soils in question.

Furthermore, the value of (Fep+Alp)/clay that is employed to define a podzolic B or spodic horizon indicated the presence of a podzolic B horizon even in the brown forest soils studied, while no spodic horizon was found even in the podzolic soils with a clearly recognizable albic horizon. Moreover, the examination of the degree of podzolization showed that the brown forest soils almost corresponded to Ochreous brown earths.     

陕西关中土垫旱耕人为土样区的基层分类研究

选择陕西关中土垫旱耕人为土地区为样区,以该地区代表性土壤土垫旱耕人为土(土)为研究对象,在野外调查、室内分析及查阅大量有关剖面资料的基础上,根据中国土壤系统分类体系,对土垫旱耕人为土(土)的基层分类进行了研究。研究表明,应用土壤颗粒大小级别、矿物学型和土壤温度状况等3项指标对土族进行划分,在0~160cm的控制层段中小于2mm的土壤平均质地,多数剖面为粘壤土,少数为壤土或砂质壤土,矿物学型属伊利石型、伊利石混合型或蛭石型,土壤温度属温性或温热土壤温度状况。土垫旱耕人为土(土)土系的控制层段拟定为从表土层上界向下160cm,对于诊断层的底部在160cm以下的,则从表土层至诊断层的下部边界,特征土层有肥熟表层、土垫表层、暗沃表层、耕作淀积层、粘化层、粘质层、CaCO3高度淀积层、CaCO3中度淀积层、CaCO3低度淀积层、氧化还原层和稚育层。根据样区9个典型剖面,结合关中地区土垫旱耕人为土(土)的有关研究资料,划分了土族和土系,并描述了各土系的典型特征及土系间的变异情况。     

诊断层和诊断特性与景观关系探讨 ——以江苏省句容某样区为例

土壤与所处的景观密切相关,诊断层和诊断特性是土壤系统分类中判定土壤类型的依据,诊断层和诊断特性与景观之间具有一定的联系,研究它们的关系有助于更好地辅助土壤调查。本文在景观理论的指导下,对江苏省句容市边城镇开展了样区土壤调查,调查采样的48个主要剖面归属于人为土、淋溶土、雏形土和新成土4个土纲、4个亚纲、9个土类、13个亚类;在此基础上,重点探讨了诊断层和诊断特性与景观之间的关系,结果表明景观能很好地指示某些诊断层和诊断特性,对景观的深入研究可以指导土壤调查与土壤系统分类类型的确定。     

典型网纹红土结构土壤细菌群落及其生态网络特征

我国亚热带地区红壤下部的网纹红土通常被认为是第四纪古气候和古环境变化的记录载体。迄今为止，对土壤细菌群落在土壤结构体尺度上的分异特征及其影响因素了解甚少。作为红壤关键带地下结构的重要组成部分，网纹红土独特的红-白相间的土体结构可能引起土壤细菌群落在其上的差异分布。阐明网纹红土结构土壤细菌群落特征对探索红壤关键带深部生态系统的生物多样性和多功能性具有重要的生态学意义。本研究以典型网纹红土结构体为研究对象，将其拆分为红色基质和白色网纹两部分，利用16S rRNA高通量测序分析红/白部分细菌群落与细菌生态网络的特征。结果表明，网纹结构体红白部分细菌群落结构差异显著，红色基质部分放线菌门和厚壁菌门等细菌显著富集；白色网纹部分酸杆菌门、硝化螺旋菌门等细菌相对丰度显著富集。细菌生态网络分析结果表明，白色网纹部分的细菌网络节点和连线较多，聚类系数较低，说明白色网纹部分细菌之间相互作用关系更复杂。典范对应分析表明，网纹结构体环境异质性造成了细菌群落在网纹红白部分的差异分布。其中质地是决定细菌群落及其生态网络差异最重要的环境因子.此外,在网纹的红色基质部分，矿质养分的含量与细菌群落的组成密切相关。     

Podzol formation in sandy soils of Finland

Podzolization occurs quickly in acidic parent materials with addition of acidic litter from coniferous trees. This study was conducted to evaluate Podzol formation and estimate lengths of time required to meet morphological and chemical criteria of podzolic B horizon and spodic horizon in Finland. Soil color, organic C, ODOE, and extractable Al and Fe were measured in a seven-pedon chronosequence (230–1800 years) and four older pedons (8300–11,300 years). The bulk mineralogical composition of the BC and C horizons was uniform with quartz, plagioclase and K-feldspar as main components and amphibole, illite and chlorite as minor components. The fine (<5 μm) fraction of selected samples was primarily amorphous allophone-like material with some mixed-layered illite–vermiculite. All pedons in the study met the criteria for albic horizons according to the FAO–Unesco, World Reference Base (WRB) and Soil Taxonomy systems. According to the FAO–Unesco system, all pedons had spodic B horizons and were classified as Podzols. According to the WRB system, none of pedons of the chronosequence had spodic horizons, whereas the older pedons met the criteria for a spodic horizon. About 4780 years were required to form a spodic horizon according to the WRB system. The oldest pedon of the chronosequence and the older pedons had spodic horizons according to Soil Taxonomy, but the younger pedons failed to meet the spodic horizon criteria. About 1520 years were required to form a spodic horizon that met the color and organic C criteria of Soil Taxonomy, whereas it took about 4780 years to meet the required accumulation of Fe and Al. This study points out the discrepancy between the color criteria and the criteria reflecting the accumulation of Al, Fe and organic matter in the B horizon.     

波兰喀尔巴阡山麓漂白淋溶土中铁锰结核的分布、形态和化学组成研究

Iron and manganese oxides are common components of soils. They frequently occur in nodules constituting important soil sorbents and play a crucial role in a number of chemical reactions in the soil environment. In addition, the oxides are very sensitive to environmental changes (moisture, pH, Eh) constituting important indicators of soil-forming processes and water movement in the landscape. The objectives of the study were: i) to examine the distribution and size of Fe-Mn nodules in Albeluvisols containing a fragipan horizon; ii) to determine the morphology and chemical composition of the nodules, and iii) to estimate the effect of the fragipan horizon on water movement within the soil profile. An investigation was carried out on five soil profiles containing a fragipan horizon and classified as Fragic Albeluvisols within the Carpathian Foothills in Poland. In the Albeluvisols studied, the maximum concentration of Fe-Mn nodules occurred in the horizon lying directly on the fragipan horizon. This suggests that the pan acts as a natural barrier restricting water infiltration and leads to the seasonal development of a perched water table promoting redox processes. The most common are coarse (1--0.5 mm) and medium (0.5--0.25 mm) irregular Fe-Mn nodules showing a gradual boundary and undifferentiated internal fabric. Eluvial horizons contained also larger amounts of round and dense nodules with a sharp boundary, suggesting frequent oxidation and reduction. The fragipan horizon contained mainly irregular and soft nodules, suggesting longer saturation with water during the year. Concentrations of trace elements (Cu, Zn) and P were higher within Fe-Mn nodules than in the surrounding soil materials, showing that iron and manganese oxides adsorbed and immobilised these elements.