利用侵蚀模型普查黄土高原土壤侵蚀状况

土壤侵蚀普查对于土地资源保护和自然灾害防治具有重要意义。为了测试抽样方法和土壤侵蚀模型在土壤侵蚀普查中的适用性,该文以陕西吴起县为试点,采用1%均匀抽样方法,调查39个抽样单元的土壤侵蚀影响因子,使用中国侵蚀预报模型CSLE(Chinese soilloss equation)估算土壤侵蚀模数,并与基于遥感数据的水蚀分级分类方法进行比较。两种方法估算的全县平均土壤侵蚀模数分别为4571和5504t/(km2a),但不同分级侵蚀强度的面积和空间分布存在较大差异。抽样方法在土地利用与覆盖、水土保持措施及土壤特性方面获得的信息量大于遥感方法,同时对于区域具有很好的代表性;使用模型估算土壤侵蚀考虑的影响因子与分级方法相比,还包括了土壤可蚀性、坡长因子以及水土保持措施因子等,由此计算的土壤侵蚀模数和强度具有更高的可信度。因此,虽然基于抽样方法和土壤侵蚀模型的土壤侵蚀普查方法也存在一定的问题,但与土壤侵蚀分类分级方法相比具有明显的优越性。     

Assisting nonsoil specialists to identify soil types for land management: an approach using a soil identification key and toposequence models

Conventional soil survey information is often unclear except to specialists. An approach using soil toposequences and a soil identification key was used to aid the translation of soil survey information into a form suitable for a nonspecialist audience with a case study from Brunei. Soil Taxonomy was used to characterize the major soil types; however, to assist end users, a complementary special‐purpose soil classification system was developed in the form of a soil identification key using plain language terms in English that were also translated into Malay. Easily recognized soil features such as depth, colour and texture were used to categorize soils to match Soil Taxonomy classes. To complement the soil identification key, conceptual soil toposequence models presented the soil distribution patterns in a visual format that local land users understood. Legacy soil survey information along with a widespread distribution of 172 soil sites from 35 traverses in 16 study areas provided a dataset to develop and test soil toposequence models and the soil identification key which both proved reliable and robust. The approach demonstrated in Brunei could be applied to other countries and landscapes.     

黄土丘陵区侵蚀土壤质量评价

通过建立侵蚀土壤质量单因素评价模型和综合评价模型,选出了黄土丘陵区适宜的侵蚀土壤质量评价方法,定量评价了该区土地利用方式对土壤质量的影响。结果表明,采用加权综合法对土壤质量进行综合评价能够较好地反映土壤质量的实际情况,敏感地反映土地利用方式变化对土壤质量的影响。应用因子分析法所筛选的8项土壤质量简化评价指标能够很好地反映29项综合评价指标的信息,评价结果具有较高的代表性。拟定了黄土丘陵区侵蚀土壤质量分级标准,将研究区土壤质量分为5级。黄土丘陵区10种土地利用类型间土壤质量差异显著,以天然乔木林地土壤质量最佳,属1级;其次是天然灌木林地和大棚菜地,土壤质量属2级;天然草地土壤质量属于3级,人工乔灌林地土壤质量接近3级;人工草地、撂荒地、农地和果园土壤质量属于4级。     

National soil data in EU countries,where do we stand?

At the European scale, soil characteristics are needed to evaluate soil quality, soil health and soil-based ecosystem services in the context of the European Green Deal. While some soil databases exist at the European scale, a much larger wealth of data is present in individual European countries, allowing a more detailed soil assessment. There is thus an urgent and crucial need to combine these data at the European scale. In the frame of a large European Joint Programme on agricultural soils launched by the European Commission, a survey was conducted in the spring of 2020, in the 24 European participating countries to assess the existing soil data sources, focusing on agricultural soils. The survey will become a contribution to the European Soil Observatory, launched in December 2020, which aims to collect metadata of soil databases related to all kind of land uses, including forest and urban soils. Based upon a comprehensive questionnaire, 170 soil databases were identified at local, regional and national scales. Soil parameters were divided into five groups: (1) main soil parameters according to the Global Soil Map specifications; (2) other soil chemical parameters; (3) other physical parameters; (4) other pedological parameters; and (5) soil biological features. A classification based on the environmental zones of Europe was used to distinguish the climatic zones. This survey shows that while most of the main pedological and chemical parameters are included in more than 70% of the country soil databases, water content, contamination with organic pollutants, and biological parameters are the least frequently reported parameters. Such differences will have consequences when developing an EU policy on soil health as proposed under the EU soil strategy for 2023 and using the data to derive soil health indicators. Many differences in the methods used in collecting, preparing, and analysing the soils were found, thus requiring harmonization procedures and more cooperation among countries and with the EU to use the data at the European scale. In addition, choosing harmonized and useful interpretation and threshold values for EU soil indicators may be challenging due to the different methods used and the wide variety of soil land-use and climate combinations influencing possible thresholds. The temporal scale of the soil databases reported is also extremely wide, starting from the '20s of the 20th century.     

基于Web的中国土种数据库

来源于第二次全国土壤普查汇总成果的中国土种数据库是目前最全面的全国性土壤数据库。它收录了20世纪80年代我国主要土种的分布、面积、性状、土地利用情况和生产性能等资料。自2000年以来,中国科学院南京土壤研究所开始建设基于Web的中国土种数据库,构造了一个包括地点与土壤类型的空间分布关系和依据中国土壤发生分类系统的分类层次关系的实体-关系(entity-relationship,E-R)数据模型,形成了具有2 473个土种典型剖面、8 751个发生层及物理化学性质的数据产品。该数据库可通过互联网广泛应用于土地退化评估、环境影响研究以及土壤碳储量研究,亦可作为基础数据指导农业生产。     

Evaluation of World Reference Base for Soil Resources and FAO Soil Map of the World using nationwide grid soil data from Denmark

Abstract. Soil classification is a tool for stratifying and generalizing information on soil resources but most systems are tailored to handle only slightly disturbed soil. We tested the applicability of the legend of the FAO-Unesco Soil Map of the World and the new World Reference Base for Soil Resources by classifying at the highest order 831 profiles from a nationwide 7 km grid survey in Denmark, where soils are developed in Quaternary glacial and marine sediments and intensively farmed. Comparison of the variability of pH and % clay +% silt of the master horizons (A, E, B, and C) within and between the major well-drained soil groupings shows that liming, fertilizing and ploughing have produced significantly deeper A-horizons with higher pH, lower % humus and C:N ratios on the two-thirds of the country that is cultivated. ‘Anthropogenic’ mollic and umbric horizons are a common result but the liming causes a random final classification of these surface horizons and, hence, random allocation of the soils in both systems. It separates cultivated soils and their undisturbed equivalents, and results in considerable within-group variation in soil texture. Grouping of cultivated and undisturbed soils, on the other hand, results in wide within-horizon pH ranges for most groups, again compromising the advantage of making useful general statements on the basis of classification. We propose that anthropogenic mollic and umbric horizons should be allowed in any soil group and that ‘anthric properties’ should be used to distinguish between profoundly changed cultivated soils and largely undisturbed soils, hereby constructing a two-tier system within each highest-order soil group. We classified the soils according to this proposal. The results show generally narrower ranges for both pH and % clay +% silt. We evaluated the within-group homogeneity by multivariate analysis of variance of pH, % clay +% silt, % clay, % humus, C:N ratio, exchangeable cations, and CEC. The results (Wilks's Lamda) show a higher degree of group compactness compared to the original FAO and World Reference Base systems.     

Automated soil map compilation

Abstract

A soil map is eonventionally prepared by an experieneed surveyor via the following three steps; (1) establishment of taxonomie class, (2) alloeation of sam pie into one of the classes, and (3) delineation of homogeneous areas in terms of mapping unit. These steps involve some degree of arbitrariness; thus soil maps prepared by two surveyors are never identical. The aim of this study is to define a eertain proeedure of soil map eompilation, by introdueing numerical handling of soil data, to obtain a reproducible and easy-to-prepare soil map, with the help of the funetions of the eomputer-based Soil Data Management System (COSMAS).

The authors applied Hayashi's theory of quantification No. 3 to numerical representation of soil profiles based on the pattern of eombination of various soil attributes relevant to soil classification. The following four soH types were recognized in the seattergram plotted using numerical va lues assigned to the soH profiles; Gley Lowland SoH, Gray Lowland Soil, Brown Lowland Soil and Pseudogley SoH. Then, using these numerical values, diseriminant analysis was carried out to classify each profile into one of the above-defined soil types. As a result, 89.7% of the observed profiles were assigned to the same soil types as assigned by a surveyor in the filed. Area delineation for each mapping unit on the basis of soil type assignment and probabHity of membership of a respective soil type group at a sampled si te was automatieally performed by an "AUTOMAP" program whieh was newly developed for COSMAS for graphic representation of soil data. The numerically prepared soi! map showed reasonable agreement with the surveyor's. A wide range of users of soil survey data can prepare various maps using the procedure proposed in this paper.     

Soil mapping for land‐use planning in a karst area of N Thailand with due consideration of local knowledge

For the development of sustainable land‐management systems in the highlands of N Thailand, detailed knowledge about soil distribution and soil properties is a prerequisite. Yet to date, there are hardly any detailed soil maps available on a watershed scale. In this study, soil maps on watershed level were evaluated with regard to their suitability for agricultural land‐use planning. In addition to common scientific methods (as underlying the WRB classification), participatory methods were used to exploit local knowledge about soils and to document it in a “Local Soil Map”. Where the WRB classification identified eight soil units, the farmers distinguished only five on the basis of soil color and “hardness”. The “Local Soil Map” shows little resemblance with the detailed, patchy pattern of the WRB‐based soil map. On the contrary, the “Local Soil Map” is fairly similar to the petrographic map suggesting that soil color is directly related to parent material. The farmers' perception about soil fertility and soil suitability for cropping could be confirmed by analytical data. We conclude that integrating local soil knowledge, petrographic information, and knowledge of local cropping practices allows for a rapid compilation of information for land‐evaluation purposes at watershed level. It is the most efficient way to build a base for regional land‐use planning.     

Soil classification and salinity mapping for determining restoration potential of cropped riparian areas

Restoration and management of riparian areas have recently become important issues. Soil and salinity surveys are required before planning restoration activities and land‐uses if the riparian area is salt‐affected. In this study, we characterise the soils and salinity conditions of a riparian area that underwent irrigated agriculture with significant soil salinisation, to assess the general site suitability for riparian restoration and potential land‐uses. Throughout the area, 19 profiles were described and classified and 95 soil samples were collected for their chemical and physical characterisation. The salinity of the 35‐ha presumably salt‐affected area was analysed by reading the bulk soil electrical conductivity (ECa) with the hand‐held electromagnetic‐induction sensor Geonics‐EM38 at 558 locations and by measuring the electrical conductivity of the saturation extract (ECe) and sodium adsorption ratio (SAR) of 60 soil samples collected at 30 of those locations. The regression of ECe on EM readings predicted ECe with R² > 0·92 at the 0–100 cm soil depth. The geo‐referenced soil classification (three soil units were established) and salinity maps identified the soil constraints for the area's restoration potential. The major limiting soil factors were soil salinity, sodicity and waterlogging in the southern half of the soil unit #3, and soil compaction in most of the area. The value of those limiting factors, along with differences in soil texture, as a means of assessing restoration potential of riparian vegetation and for identifying suitable land‐uses for the three soil units was discussed. Agro‐forestry, planned grazing, recreational and educational land‐uses are possible for the site. Copyright © 2007 John Wiley & Sons, Ltd.     

Chemical properties and pedogenesis of yellowish/yellow brown forest soils in the submontane and mountain zones of Kyushu district,southwestern Japan

Abstract

This study aimed to clarify pedogenetic processes and classification of yellowish Brown Forest Soils according to the Classification of Forest Soils in Japan and the Yellow Brown Forest soils according to the Unified Soil Classification System of Japan in the warm and cool temperate forest of Kyushu district, Japan. In addition, the study aimed to clarify a problem with the Unified Soil Classification System of Japan. Thirty-six soil profiles of Brown Forest Soils, including 13 yellowish Brown Forest Soils and 15 Yellow Brown Forest soils, were compared with regard to their chemical properties and the relationship with climatic conditions was assessed. The yellowish Brown Forest Soils had thin A horizons, low pH and low levels of free oxides in the B horizons, and a low amount of silica and a high aluminum and iron to silica ratio. These features were related to the paleo reddish weathering. The immaturely developed A horizon of the yellowish Brown Forest Soils was caused by these weathered, low-activity substances. The Yellow Brown Forest soils had low levels of active iron oxides and a low activity ratio of free iron oxides compared with the Haplic Brown Forest soils in the same thermal climatic conditions. The activity ratio of free iron oxides was correlated to mean annual air temperature with the carbon stocks and with many other chemical properties. Accordingly, classification of Brown Forest Soils was clearer according to thermal climatic conditions. The activity ratio of free iron oxides can become an effective index that distinguishes Yellow Brown Forest soils under warm temperate lucidophyllous forest and Haplic Brown Forest soils under cool temperate broad-leaved deciduous forest with considerable vertical soil zonality.     

Soil Erosion Assessment in Kondoa Eroded Area in Tanzania using Universal Soil Loss Equation,Geographic Information Systems and Socioeconomic Approach

Soil conservation measures including cutoff drains, tree planting, Crops diversifications and destocking were implemented in Kondoa eroded area (KEA) for decades. This study assessed soil erosion changes in KEA and examined drivers of changes using Universal Soil Loss Equation, Geographic Information Systems and socioeconomic survey. Soil erosion was predicted by using data on soil, digital elevation model, rainfall and land use/cover visually interpreted from multitemporal satellite imageries. The predicted average soil erosions were 14·7, 23 and 15.7 Mg ha⁻¹y⁻¹ during 1973, 1986 and 2008, respectively. The area under very high soil erosion severity that was 30% in 1973, 26% in 1986 and 25% in 2008, whereas the area with high erosion severity was 26% in 1973 changed into 49% in 1986 and 2008 indicating recent stabilization. The area with moderate erosion increased from 15%, 16% and 18% during the same period. Field survey confirms a decrease of soil erosion in KEA compared with the past showing better soil conservation. Age of farmers, long‐term adoption of conservation practices and on‐farm tree planting were found to be the major factors contributing toward reduced soil erosion. Major limitations in soil conservation were poor mainstreaming of conservation activities on local production systems and lack of institutions promoting conservation at the community level. The study concluded that long‐term conservation investment for restoration, protection and socioeconomic support contributes significantly in land rehabilitation in KEA. Copyright © 2013 John Wiley & Sons, Ltd.     

World Reference Base for Soil Resources—Its fourth edition and its history

The fourth edition of the international soil classification system World Reference Base for Soil Resources (WRB) was released in 2022. It maintains the 32 Reference Soil Groups at the first classification level. Most qualifiers (second level) and most diagnostic horizons, properties and materials were maintained but some were abolished and new ones introduced. The main part of the fourth edition is followed by six annexes, most of them are new. For the first time, the WRB has a Field Guide (Annex 1) to facilitate field survey and to assure that all field characteristics required in the classification are reported. The fourth edition also provides designations for horizons and layers (Annex 3), which was not the case in the second and the third edition. The wordings of the definitions were harmonized, and the same features are worded in the same way throughout the text (including the annexes). Ambiguities have been corrected and many definitions written in a more concise and a more didactical way. The WRB has a long history. Four editions have been published: 1998, 2006 (with update 2007), 2014 (with update 2015) and 2022. Editor is the Working Group WRB of the International Union of Soil Sciences. The WRB followed the Legend and the Revised Legend of the Soil Map of the World. This map was edited by FAO (Food and Agriculture Organization of the United Nations) and UNESCO, and the system is known as the FAO Soil Classification System. In addition, WRB incorporated ideas from the former Working Group International Reference Base for Soil Classification that existed from 1982 to 1994.     

民勤绿洲荒漠交错带不同土地覆被下土壤养分分布特征

以西北干旱区民勤绿洲荒漠交错带为例,选取民勤沙生植物园、东坝镇、苏武山等8个样带221个样点开展不同土地覆被类型下的土壤养分含量及土壤肥力综合评价研究.结果表明:(1)土壤有机质含量表现为绿洲区＞绿洲荒漠过渡带＞荒漠区的梯度变化;受人类活动影响和荒漠景观特征的影响,不同样带内土壤养分含量离散程度较大,变异系数为16.67％～410.68％,且土壤养分样带内变异程度基本呈现出沿荒漠—绿洲荒漠交错带—绿洲逐渐增加的趋势.(2)荒草地、灌木林地、乔木林地和裸地的土壤N,P,K含量主要受土壤质地和植被类型的影响而呈现出差异.(3)不同土地覆被下土壤肥力质量指数大小为草地(0.552)＞灌木地(0.057)＞乔木地(-0.642)＞裸地(-0.677),草本和灌木具有良好的土壤培肥作用.     

关于“中国土壤系统分类中基层分类研究”的思路

中国土壤系统分类中的基层分类研究的重点是通过选择分异特性和恰当地划分分异特性区间来建立分类指标体系 .分异特性应是易于鉴别的对土壤生产力有重要影响的相对稳定的土壤性质 ;以使土壤分类便于应用于土壤调查 ,更好地服务于土地评价和规划 .研究变量和因变量的定量化关系或土壤性质与土地生产力的定量化关系是准确划分分异特性区间的有效方法 .基层分类最好采用检索方法 ,以求分类的唯一性 .连续命名法可以明确表达分类单元的属性     

抛荒土地不同处理及利用方式对喀斯特地区土壤微生物的影响

土壤微生物特性是土壤养分的储存库,土壤养分也影响土壤微生物活性,了解两者的相互作用机制对土地利用与管理提供理论依据,而喀斯特地区不同土地利用方式相关研究较少。基于喀斯特峰丛洼地火烧、刈割、刈割除根、封育、种植玉米、种植桂牧1号杂交象草6种坡面典型的土地利用方式的动态监测样地建设与调查,该文分析了不同土地利用方式下土壤微生物特性,揭示其与土壤养分相互作用机制。结果表明,不同土地利用方式对土壤养分的影响不同,土壤有机质（soil organic matter,SOM）、全氮（total nitrogen,TN）、全磷（total phosphorus,TP）、碱解氮（available nitrogen,AN）等沿封育、火烧、刈割、刈割除根、种植桂牧1号、种植玉米等土地利用方式的转变而减少;不同土地利用方式土壤微生物生物量各不同,土壤微生物量碳（microbial biomass carbon, MBC）：244.98～1 246.89 mg/kg、土壤微生物量氮（microbial biomass nitrogen,MBN）：35.44～274.69 mg/kg、土壤微生物量磷（microbial biomass phosphorus,MBP）：30.88～64.72 mg/kg,其中,种植玉米土壤微生物生物量均最低,其土壤质量退化现象严重;不同土地利用方式土壤微生物种群数量及组成影响不同,种植玉米和桂牧1号杂交象草细菌占绝对优势,而火烧、刈割、刈割除根及封育均以放线菌占绝对优势,真菌的比例很少;不同土地利用方式土壤微生物特性与土壤养分之间相互作用关系不同：火烧的土壤TP和MBP、全钾（total potassium,TK）与MBC、TN与放线菌作用最强且均呈正相关,刈割的土壤TN与MBC呈正相关,刈割除根的速效磷（available phosphorus,AP）与MBN正相关,封育的pH值与MBC、真菌负相关,种植玉米的TN、TK与MBP负相关,种植桂牧1号杂交象草的pH值与真菌负相关、与放线菌正相关;聚类分析可以将喀斯特峰丛洼地6种土地利用方式划分为4类,其中封育和火烧最好。     

Bodensystematik und Bodenklassifikation Teil I: Grundbegriffe

Soil systematics and classification systems Part I: Fundamentals Soil‐ordering systems are primarily based and developed on one of two underlying principles: They are either categorized according to soil‐forming processes, or the formation of categories develops by chosen parameters. This perspective has already been established in the literature, though it is often confusing as many terms are defined and applied differently. In this contribution, the various definitions of systematics, classification, taxonomy, and identification will be clearly differentiated and summarized. The core of our work is to clearly define and contrast three terms: systematics, classification, and identification. Systematics is the fundamental scientific and deductive ordering of objects into systematic units. The purpose of this approach is to organize the entire spectrum of knowledge within a discipline into a transparent and manageable form. Classification, in direct contrast to systematics, is goal‐oriented and an inductive ordering of objects. Thus, the ordering scheme consists of classes which are clearly parameterized. Identification is the ordering of new objects into an already existing systematics or classification system. Close attention is paid to both the differences and the similarities between a systematics and a classification system, especially pertaining to their practical applications. The identification requires that the category‐forming characteristics can be measured (e.g., for soil systematics, these are the soil‐forming processes and factors). Currently, it is unfortunately not feasible to objectively quantify most soil‐forming processes. Thus, most attempts at categorizing soils by systematics are hypothetical and highly subjective in nature. The resulting identification derived from the soil systematics approach is open to questions and contestable, since a graded measuring system does not yet exist to verify these determinations. In contrast, a soil‐classification system does allow an objective soil‐profile identification, although such systems are conceived pragmatically and designed for a practical purpose (e.g., not scientifically based on process intensities). Unfortunately, such a classification system cannot be applied as a universal scientific categorization system due to this method of conception. Both categorization approaches are required in soil science in order to satisfy both the practical and the scientific aspects of the field. However, substantial research must be done to complete and verify systematics. The only viable short‐term solution is through the development of a graded classification system where the categories of the system are directly derived from the current systematics approach. In the long run both the exact investigation and the detailed modeling of the soil‐forming processes are inevitable.     

The influence of different types of urban land use on soil microbial biomass and functional diversity in Beijing,China

Soil microbes in urban ecosystems are affected by a variety of abiotic and biotic factors resulting from changes in land use. However, the influence of different types of land use on soil microbial properties and soil quality in urban areas remains largely unknown. Here, by comparing five types of land use: natural forest, park, agriculture, street green and roadside trees, we examined the effects of different land uses on soil microbial biomass and microbial functional diversity in Beijing, China. We found that soil properties varied with land uses in urban environments. Compared to natural forest, soil nutrients under the other four types of urban land use were markedly depleted, and accumulation of Cu, Zn, Pb and Cd was apparent. Importantly, under these four types of land use, there was less microbial biomass, but it had greater functional diversity, particularly in the roadside‐tree soils. Furthermore, there were significant correlations between the microbial characteristics and physicochemical properties, such as organic matter, total nitrogen and total phosphorus (P < 0.05), suggesting that lack of nutrients was the major reason for the decrease in microbial biomass. In addition, the larger C/N ratio, Ni concentration and pool of organic matter together with a higher pH contributed to the increase in microbial functional diversity in urban soils. We concluded that different land uses have indirect effects on soil microbial biomass and microbial community functional diversity through their influence on soil physicochemical properties, especially nutrient availability and heavy metal content.