THE RELATION BETWEEN COST AND UTILITY IN SOIL SURVEY

This paper discusses how to compare the utility of soil maps. For three contrasting areas, in Southern England, it compares the utilities of a number of single-property and general purpose (series) soil maps, produced by free and grid survey, at map scales from 1 :20,000–1:70,000. The‘purity’of series mapping units increases with survey effort. Where the soil boundaries had fairly clear external expression free survey was superior to grid survey. On average the purity of maps by grid survey was higher than for maps by free survey at comparable survey effort. The uniformity of soil properties within mapping units was measured by relative variance (RV)= within-unit variance/total variance, (1–RV) indicates the increased precision achieved by the soil map. It increased with survey effort. For series maps by free or grid survey (1–RV) depended on how closely soil properties were associated with profile classes, and on the extent to which soil boundaries could be mapped on their external expression. Free survey was preferred at scales between 1: 100,000 and 1:30,000, when the soil boundaries could be mapped on their external expression, (1–RV) for the profile classes on which the mapping units are defined puts a ceiling to the utility of series maps (grid or free) which is already nearly achieved at map scales near 1:25,000. Except for properties very poorly associated with profile classes, single property maps do not have great advantage over series maps at medium map scales, but they attain higher values of (1–RV) at scales greater than 1: 25,000.     

海南岛地形-母岩(母质)单元与土壤系统分类类型关系及其在编绘土壤图中的应用

对海南岛 2 43个土壤剖面 ,按中国土壤系统分类体系 ,逐一进行鉴别、检索、分类定名 ;并讨论归纳出地形 -母岩 (母质 )单元与土壤系统分类类型的对应关系 ;然后 ,根据对应关系试拟按土壤系统分类的全岛土壤图的制图单元 (土壤部分 ) ,编绘选择地段的土壤草图 ( 1∶5 0万 )。全岛共设有 5 0个制图单元 (土壤部分 )。结果表明 ,用本研究中的方法步骤编绘按土壤系统分类的土壤草图 ,比单纯用已有按发生分类的土壤图直接进行两个系统间土壤名称更换 ,更具有客观性和可操作性。     

SOIL CLASSIFICATION IN THE SOIL SURVEY OF ENGLAND AND WALES

The development of soil classification as a basis for soil mapping in England and Wales is briefly reviewed, and a system for future use is described. The things classified are soil profiles, and classes are defined by relatively permanent characteristics that can be observed or measured in the field, or inferred within limits from field examination by comparison with analysed samples. Profile classes are defined at four categorical levels by progressive division, and are termed major groups, groups, subgroups, and soil series respectively. Classes in the three higher categories are defined partly by the composition of the soil material and partly by the presence or absence of particular diagnostic horizons, or evidence of recent alluvial origin, within specified depths. Soil series are distinguished by other characteristics, chiefly lithologic, not differentiating in higher categories. Most of the soil groups, regarded as the principal category above the soil series, are closely paralleled in other European systems, in the U.S.D.A. system (7th Approximation with subsequent amendments), or in both. Compared with the system used hitherto, the main innovations are the use of specific soil properties to define classes at all categorical levels, and the separation at group level of classes based primarily on inherited lithologic characteristics. The soil-profile classification provides a uniform basis for identifying soil map units, considered as classes of delineated soil bodies. When a map unit is identified by the name of a profile class, it is implied that most of the soil in each delineation conforms to that class, and that unconforming inclusions belong to one or more closely related classes or occupy an insignificant proportionate area. Map units identified by land attributes not differentiating in the profile classification are termed phases.     

全国第二次土壤普查与土壤肥料科学的发展

建国40年，中国开展了两次全国土壤普查。本文简要回顾了第一次全国土壤普查，着重综述全国第二次土壤普查在发展土壤肥料科学方面的成就。全国第二次土壤普查是《1979-1985年全国科学技术发展规划纲要（草案）》重点科技研究项目内容这一，在科技顾问组的指导下，采用新的大比例尺地形图和遥感、测试、微型电子计算机等调查制图和化验手段，取得丰硕的科研成果。对于发展中国土壤分类科学、充实了土壤基层分类的基本单元，建立土壤测试网络、改进土壤分析方法以及普查成果在制订农业区划、科学施肥、土壤改良、基地建设等方面广泛应用，为发展农林牧业生产服务。并对土壤普查中建立的土壤肥力监测网作了论述。本文从一个侧面反映了中国土壤肥料学科的发展。     

THE RATE OF SOIL SURVEY IN BRITAIN

Typical rates of soil survey (area, length of boundary and number of observations per day or hour) are presented for routine surveys on 1:25,000 and 1:10,560 base maps by the Soil Surveys of Scotland, and of England and Wales, in five areas. The distance a soil surveyor walks between observations sites each day is highly correlated with (Area surveyed x No. of observation sites).     

土壤pH与烤烟钾素营养关系的研究

选择代表性的贵州植烟土壤,施石灰提高ｐＨ,施硫酸亚铁和硫磺粉降低ｐＨ,通过两年烤烟盆栽试验,研究了土壤ｐＨ对烤烟钾营养状况的影响。结果表明：土壤ｐＨ平均为５．３３和６．１时烟叶产量较高;超出此ｐＨ范围,产量有下降趋势;ｐＨ低于５．０产量急剧下降．烟叶吸钾状况及施钾效果均以土壤平均ｐＨ５．３３的最高;ｐＨ低于５．０及高于６．１对烟株的钾素营养都有不同程度的影响,以低ｐＨ对钾吸收的抑制作用最大。初步提     

SOIL GENESIS IN RELATION TO GROUNDWATER AND SOIL MOISTURE REGIMES NEAR VEGREVILLE,ALBERTA1

The study was designed to obtain information on flow and salinity of the groundwater, and on moisture regimes above the water table at selected sites near Vegreville, Alberta, and to relate this information to features of soil genesis revealed by soil mapping and analysis. All soils on the lower slopes, unlike those at upper elevations, contained accumulations of salts and gypsum, but the depth of salt accumulation and therefore the kind of soil appeared to be related only partly to current groundwater flow directions and the depth of the water table. The sodium content of the discharging groundwater and past flow conditions also appeared to be important. Lateral flow above the water table is suggested as being of possible importance in desalinization of surface horizons.     

THE OCCURRENCE AND PREDICTION OF CLODS IN POTATO RIDGES IN RELATION TO SOIL PHYSICAL PROPERTIES

Clod crushing resistance, bulk density, moisture content, and size distribution, together with fifteen bulk soil physical properties, were determined at thirty sites. Regression analyses indicated that the plasticity index of the soil is the principal property affecting both the clod crushing resistance and the yield of clods. Other less closely related properties are not always consistent in their effect between clod size ranges. A‘clod factor’ was derived from the product of the clod crushing resistance and the weight of clods in the ridge for each soil. The clod factor is linearly correlated with plasticity index (r= 0·587, P= 0·002) and a clod factor > 1000 was found for soils with a plasticity index greater than about 5. Harvest observations suggest that where the clod factor exceeded 1000, the efficiency of a mechanical potato harvester was reduced.     

SOIL ORGANIC CARBON STOCK AND FRACTIONS IN RELATION TO LAND USE AND SOIL DEPTH IN THE DEGRADED SHIWALIKS HILLS OF LOWER HIMALAYAS

The proportional differences in soil organic carbon (SOC) and its fractions under different land uses are of significance for understanding the process of aggregation and soil carbon sequestration mechanisms. A study was conducted in a mixed vegetation cover watershed with forest, grass, cultivated and eroded lands in the degraded Shiwaliks of the lower Himalayas to assess land‐use effects on profile SOC distribution and storage and to quantify the SOC fractions in water‐stable aggregates (WSA) and bulk soils. The soil samples were collected from eroded, cultivated, forest and grassland soils for the analysis of SOC fractions and aggregate stability. The SOC in eroded surface soils was lower than in less disturbed grassland, cultivated and forest soils. The surface and subsurface soils of grassland and forest lands differentially contributed to the total profile carbon stock. The SOC stock in the 1.05‐m soil profile was highest (83.5 Mg ha⁻¹) under forest and lowest (55.6 Mg ha⁻¹) in eroded lands. The SOC stock in the surface (0–15 cm) soil constituted 6.95, 27.6, 27 and 42.4 per cent of the total stock in the 1.05‐m profile of eroded, cultivated, forest and grassland soils, respectively. The forest soils were found to sequester 22.4 Mg ha⁻¹ more SOC than the cultivated soils as measured in the 1.05‐m soil profiles. The differences in aggregate SOC content among the land uses were more conspicuous in bigger water‐stable macro‐aggregates (WSA > 2 mm) than in water‐stable micro‐aggregates (WSA < 0.25 mm). The SOC in micro‐aggregates (WSA < 0.25 mm) was found to be less vulnerable to changes in land use. The hot water soluble and labile carbon fractions were higher in the bulk soils of grasslands than in the individual aggregates, whereas particulate organic carbon was higher in the aggregates than in bulk soils. Copyright © 2012 John Wiley & Sons, Ltd.     

土壤中含钾矿物的研究--Ⅰ.含钾矿物中钾的形态及其释放

土壤中的含钾矿物含有大量的钾,这些钾素是植物营养的可能给源,早已引起农业化学家的注意。土壤中的主要含钾矿物有黑云母、白云母、伊利石和长石等。研究土壤中含钾矿物的种类及其性质,对充分利用土壤中的钾素及合理施用钾肥具有一定的指导意义。本文着重研究四种含钾矿物的一些物理化学特性。     

东北黑土有机质和酶活性与土壤肥力的关系

在前人和我们以往工作的基础上,我们认为,研究土壤肥力,既要考虑“体质”(指比较综合地、全面地反映土壤肥力的基础物质的组成与特征),又要考虑“土体”(指耕层及其连接部分),才能找到接近实际的肥力指标。本项研究试图探索东北黑土中有机质和酶活性与土壤肥力的关系。     

国外评价土壤侵蚀与土壤生产力关系的模式

土壤侵蚀减少了植物可利用的有效水分,损失了土壤的营养物质,破坏了土壤肥力结构,影响农业耕作制度,从而严重地降低了土壤生产力。土壤侵蚀与土壤生产力关系的模式(EPIC),系统地定量地表达了土壤侵蚀与土壤生产力的相互关系。这个模式包括水文、气象、水蚀和风蚀、氮磷元素、土壤温度、作物生长状况、耕作与作物残茬的处理方法、经济因子和土壤排灌与施肥等9个因子,共36个方程。为了保护和提高土壤生产力,我国需要发展这项研究工作,制定具有中国特色的土壤侵蚀与土壤生产力关系的模式。     

土壤低吸力段持水性能及其与早期土壤干旱的关系研究

本文研究了东北5种耕作土壤<1巴的低吸力段持水性能,包括影响低吸力段持水量的因素、所吸持水分对植物的有效程度、比水容量及脱水速度等.根据东北地区春旱尽管程度不同,但发生较为普遍的这一特点,分析、比较各种土壤基质本身存在的差异,并就它们对早期土壤干旱的抗逆能力作出评价.结果表明,熟化程度较高的草甸棕壤最优,而砂壤质冲积性草甸土最差.     

中国土壤分布与气候条件的联系

系统是由相互联系、相互制约的若干部件组成的具有一定结构和特定功能的整体。自然界的任何系统,均与其环境相关联。系统与环境的关系,历来为人们所注意。熊毅教授将土壤生态系统定义为“研究土壤与环境条件的相互关系,以及系统本身的结构、功能、平衡与演变规律的一门科学”。     

土壤颗粒组成与固定态铵之间的关系

大量研究表明,固定态铵的含量与土壤质地有关.李生秀等人的研究表明[1],西北地区土壤的固定态铵含量与粘粒含量呈显著正相关,与砂粒含量呈显著负相关;Feigin和Yaalon的测定证明,以色列129种钙质土固定态铵含量与粘粒(＜0.002 mm)含量显著正相关(r=0.63,p＜0.01)[2];施书莲等人[3]报道,棕壤、栗钙土、黑土、棕钙土和红壤带土壤中的固定态铵含量与粘粒、粘粒及细粉砂含量之和的相关均达到0.01显著水准.这些结果说明,固定态铵主要存在于粘粒和粉粒中,而砂粒中几乎没有[4].     

IODINE IN SOIL PROFILES IN RELATION TO IRON AND ALUMINIUM OXIDES AND ORGANIC MATTER

The iodine content in successive 10 cm horizons of eighteen soil profiles from England and Wales was determined and correlated with contents of‘free’ aluminium and iron oxides (oxalate-soluble) and organic matter. The pattern of change in iodine content with depth varied considerably with soil type. In the rendzina soils, the content was relatively high in the surface 10 cm but declined markedly with depth. In the podsols, iodine was low at the surface but increased in the B horizon: in one of these soils an iron pan of about 1 cm thickness had an iodine content as high as 37.6 mg/kg. In two soils derived from Ordovician, and one from igneous, rock material, the iodine content was relatively high (up to 25 mg/kg) with maximum values at intermediate depths. In contrast, soils derived from river alluvium and from lowland clays generally had low iodine contents (< 6 mg/kg) which showed little variation with depth in the profile. In a peat soil the iodine content was relatively high in the horizons above 60 cm but was low (1. 3 mg/kg) in the underlying clay. In all 154 samples from the eighteen sites, iodine content was closely correlated with oxalate-soluble aluminium (r= 0.834***) but not with oxalate-soluble iron (r= 0. 35) or organic matter (r= 0.37). However, in the five most acidic soils, with pH below 4. 8, the iodine content was more closely correlated with iron than with aluminium.     

黄土地区降雨特性与土壤流失关系的研究

本文对黄土地区5种降雨参数与土壤流失量的相关性进行了研究。结果表明：10—30分钟最大降雨量的瞬时雨率，是与土壤流失量的相关性较为密切的一个降雨参数，其中15分钟的最大降雨量与土壤流失量的关系最为密切，其相关系数达0.90。     

低丘红壤区旱地土壤渗透性与可蚀性定量关系的研究

应用人工模拟降雨仪和Guelph仪对我国南方低丘红壤区旱地土壤的渗透性与可蚀性之间的定量关系进行了研究,结果表明,第四纪红色土和红砂发育的旱地坡地0－5cm表层土壤饱和渗透率Kfs与土壤的可蚀性K呈现负相关,且它们之间的定量关系可概括为：K≈a.K^-bfs c,其中a,b,c均为土壤有关的系数。