Bodenchronosequenzen aus Lockersedimenten der Lechterrassen

Soil Chronosequences derived from Non-Consolidated Sediments of the River Lech Terraces. . During the glacial and postglacial periods 16 river terraces were formed in the Lech Valley. Their non-eroded soils derived from carbonate rich gravel and from silt represent two chronosequences. The aim of this paper is to describe 9 series of the terraces No. 1, 8, 10, 13, 14 and 15 and to explain their genesis regarding the time as a soil forming factor. Due to the result of this paper the following conclusions were made:

• 1 It is assumed that the decalcification of the sediments started immediately after the terrace formation. With growth of vegetation the decalcification rate increased, with increasing age of the soils it decreased again.
• 2 Organic matter content of the soil remained constant for a long time.
• 3 Because of the high carbonate contents of the sediments the soils became acid very slowly. Even in the stadium of a brown earth (after approximately 3000 years) the grade of acidity is still minor.
• 4 The total CEC of the soils depends not so much on their age as on their thickness and their content of organic matter. The accretion of organic matter has the highest influence on the CEC increase in the initial stages of soil formation.
• 5 The silicate weathering started before the bulk sample was decalcificated completely.
• 6 Clay minerals were converted in the following way: Illite (mica) → Vermiculite → pedogenic Chlorite Smectites wheathered already in the stage of a brown earth (profile B₃).
• 7 Clay illuvation took place shortly after the decalcification of the upper horizons. A reddish brown plasma was formed in the brown earths (B₁, B₂) and the red brown podsolics (L₁, L₂). It imparts the intensiv colour (5 YR 4/8) of the argillic horizons. The hue of this plasma is not due to a higher iron contents. It is presumed that the red plasma was formed during the Boreal, because the soils which derived from silt contain only a brown plasma.

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苏、浙、皖、赣边界山地土壤的特征及其分类问题

本文在苏、浙、皖、赣四省边界亚热带庐山、黄山、天目山和马鞍山等山地(低山区)土壤野外考察的基础上,将该区代表性山地土壤进行了系统理化分析,认为这些土壤的发生特征与亚热带北部水平带上的黄棕壤不同,应归属于富铝土纲中黄壤土类,并提出了初步分类指标,以供有关方面参考.     

免耕法对土壤结构影响的研究

通过对江苏省５大农区５个点连续免耕两年后土壤容重收缩性能和破碎强度的测定,结果表明：免耕能改善土壤结构和土壤排水通气状况。体变率与土壤〈０．０１ｍｍ的物理性粘粒和〈０．００１ｍｍ粘粒含量相关密切;常耕与免耕破碎强度的差值也与粘粒含量有一定的相关。     

几种土壤对砷酸盐的吸附

砷化合物一般都具有毒性,它对环境的污染引起人们的重视.砷污染土壤后,被土壤吸附、贮存.同时,通过植物的摄取,可进入动物和人体中.植物吸收的砷量和受害的程度,不仅与土壤砷的水平有关,而且还受土壤吸附砷的状况的影响.中国科学院南京土壤研究所试验研究指出,按土壤对砷的吸附量的差异而规定各种土壤的最大允许残留量.     

陕西省农田土壤硫含量空间变异特征及亏缺评价

陕西省 13种耕地土壤 30 5个表层 (0～ 2 0cm)土壤样点分析结果表明 :该省土壤全硫和用0 0 1molL-1Ca(H2 PO4) 2 浸提的有效硫含量分别为 33～ 76 9mgkg-1(均值 36 0mgkg-1)和 4 6～ 15 7 3mgkg-1(均值 2 9 3mgkg-1) ,其中黑垆土 (普通干润均腐土 )、绵砂土 (灌淤湿润砂质新成土 )的有效硫平均含量最低。土壤全硫具有中等空间相关性 ,有效硫空间相关性较差。土壤全硫和有效硫分布具有渐变性 ,其最大相关距离分别为 5 31km和 34km。全硫以较大区域变异为主 ;有效硫以小区域变异为特征。陕西省耕地土壤有效硫含量低于硫亏缺临界值 (18 5mgkg-1)的占总面积的 13 9% ,相当于 5 3 7万hm2 农田缺硫。陕西省中部地区 ,尤其是延安西部地区土壤硫亏缺风险较大     

可变电荷土壤表面酸碱模型及其计算机模拟

在假定土壤对酸碱的缓冲作用全由表面基团反应所控制的基础上,建立了一个描述可变电荷土壤酸碱滴定曲线的模型,并在计算机上对实验结果进行了模拟。结果表明,本模型可以较好地描述土壤酸碱滴定曲线,提供土壤的酸强度(K_a)和酸容量(S_t),并可进一步提供土壤的酸缓冲容量曲线。本模型对了解和认识土壤酸化和吸附等过程具有一定的意义。     

华南主要土壤类型的光谱特性与土壤分类

本文研究了华南地区主要土壤的光谱反射特性，进行了土壤光谱的主组元分析、模糊聚类及与土壤理化性状作相关性分析，土壤光谱特征分类与现行中国土壤分类系统及中国土壤系数分类进行了比较对照。其主要结果表明，华南地区主要的光谱曲线的形态特征，主要表现为平直型（玄武岩发育砖红壤类）、缓斜型（水稻土类）和陡坎型（红、黄壤类）三种类型；土壤光谱分类与按母质母岩划分高度一致；应用主组元分析对土壤光谱进行分类，结果与现     

苏南和赣东北低山区的森林土壤

在江苏省宁镇、宜溧和江西省东北部三个低山区,以20个代表性土壤剖面作典范变量分析,结果表明,在典范变量1、2构成的直角坐标平面上,按这三个低山区划分的4类土壤(基性岩发育的黄棕壤、普通黄棕壤、红黄壤、红壤),置信区间交叠,土壤个体之间的性质为连续变化、逐渐过渡。从中可见,各区内土壤个体都包括不同发育阶段的产物。参照中国土壤系统分类方案(1987),可把这三个低山区的土壤划归4纲7类中的8个亚类,土壤类型在总体上仍表现出从北向南逐渐由硅铝土过渡到铁铝土,以及每一地区由初育土逐渐过渡到成熟土的总趋势,但各亚类界线与三个地区的地理分界线并不完全重合。根据南京附近低山丘陵地区70个土壤剖面的数据,以及相应标准地上的林木生长状况,将上述各亚类再划分为共计10个土壤生态型。     

苏北海涂围垦区土壤质量综合评价研究

以苏北海涂围垦区为研究区域,选取与作物生长密切相关的理化性质作为评价指标,分别采用相关分析法与主成分分析法确定权重系数,并应用综合指数法对土壤质量进行定量评价,获取区域土壤质量综合评价分级图.结果表明:围垦区土壤质量状况总体较差,存在一定程度盐渍化危害,土壤有机质和氮素含量偏低,碱解氮亏缺尤为严重.有机质是重要的土壤质量评价因子,土壤盐分与地下水矿化度是土壤质量的主要限制因子.相关分析法和主成分分析法对土壤质量的评价结果较为一致,r2 = 0.933 9**.围垦区不同部位土壤质量差异较大,围垦区西部棉花地土壤质量总体优于东部水稻地,且不同评价方法得到的土壤质量分级图具有空间相似性.该结果可为滩涂区中、低产地的精确施肥、障碍土壤的科学管理提供参考依据.     

The influence of long-term cultivation on soil properties and patterns in an undulating terrain in Poland

Soil utilization has, for many years, strongly influenced the properties of soils in the undulating terrain of the Lublin Upland. Population increase and suitability of the soils (particularly Luvisols, Cambisols and Chernozems derived from loess and loess-like formations) for arable agriculture were the main reasons for deforestation. This led to erosion, which caused changes in soil morphology and the development of a mosaic soil cover. Accelerated erosion was strongest on slopes exceeding 18%. It resulted in selective loss of clay. The main changes in silty soils developed from loess and loess-like deposits occurred in the first few decades after cultivation started. They included a decrease in organic matter content from an average of 2.3% organic C in the forest soils to about 1% in the arable soils. No further changes in humus content were observed, but the proportion of fulvic acids increased at the expense of humic acids. The pH_KCl rate decreased at the slope foot from about 5.8 to 5.0. Morphological changes in rendzinas were much lower than in the soils derived from loess. We do not expect big changes in these soils in the next 100 years if their use remains the same.