中国土壤分类法中铁铝土的分类

The development of the classification of ferrallitic soils in China is reviewed and the classification of Ferralisols and Ferrisols in Chinese Soil Taxonomy is introduced in order to discuss the correlation between the ferrallitic soil classification in the Chinese Soil Taxonomy and those of the other soil classification systems. In the former soil classification systems of China, the ferrallitic soils were classified into the soil groups of Latosols, Latosolic red soils, Red soils, Yellow soils and Dry red soils, according to the combination of soil-forming conditions, soil-forming processes, soil features and soil properties. In the Chinese Soil Taxonomy, most of ferrallitic soils are classified into the soil orders of Ferralisols and Ferrisols based on the diagnostic horizons and/or diagnostic characteristics with quantitatively defined properties. Ferralisols are the soils that have ferralic horizon, and they are merely subdivided into one suborder and two soil groups. Ferrisols are the soils that have LAC-ferric horizon but do not have ferralic horizon, and they are subdivided into three suborders and eleven soil groups. Ferralisols may correspond to part of Latosols and Latosolic red soils. Ferrisols may either correspond to part of Red soils, Yellow soils and Dry red soils, or correspond to part of Latosols and Latosolic red soils.     

Classification of Ferrallitc Soils in Chinese Soil Taxonomy

The development of the classification of ferrallitic soils in China is reviewed and the classification of Ferralisols and Ferrisols in Chinese Soil Taxonomy is introduced in order to discuss the correlation between the ferrallitic soil classification in the Chinese Soil Taxonomy and those of the other soil classification systems.In the former soil classification systems of China,the ferrallitic soils were classified into the soil groups of Latosols,Latosoilc red soils,Red soils,Yellow soils and Dry red soils,according to the combination of soilforming conditions,soil-forming processes,Soil features and soil properties.In the Chinese Soil Taxonomy,most of ferrallitic soils are classified into the soil orders of Ferralisols and Ferrisols based on the diagnostic horizons and /or diagnostic characteristics with quantitatively defined properties.Ferralisols are the soils that have ferralic horizon,and they are merely subdivided into one suborder and two soil groups.Ferrisols are the soils that have LAC-ferric horizon but do not have ferralic horizon.and they are subdivided into three suborders and eleven soil groups.Ferralisols may correspond to part of Latosols and Latosolic red soils.Ferrisols may either correspond to part of Red soils,Yellow soils and Dry red soils,or correspond to part of Latosols and Latosolic red soils.     

发生分类与中国土壤系统分类的参比基准研究

Soil classification is the foundation for exchange and extension of research findings in soil science and for modern management of soil resources. This study explained database and research methodology to create a cross-reference system for translating the Genetic Soil Classification of China （GSCC） into the Chinese Soil Taxonomy （CST）. With the help of the CST keys, each of the 2 540 soil species in GSCC has been interpreted to its corresponding soil order, suborder, great group, and sub-group in CST. According to the methodology adopted, the assigned soil species have been linked one another to their corresponding polygons in the 1：1000 000 digital soil map of China. Referencibility of each soil species between the GSCC and CST systems was determined statistically on the basis of distribution area of each soil species at a high taxon level of the two systems. The soils were then sorted according to their maximum referencibility and classified into three categories for discussion. There were 19 soil great groups in GSCC with maximum referencibility 〉 90% and 22 great groups between 60%-90%. These soil great groups could serve as cross-reference benchmarks. There were 19 great groups in GSCC with maximum referencibility 〈 60%, which could be used as cross-reference benchmarks until new and better results were available. For these soils, if the translation was made at a lower soil taxon level or on a regional basis, it would improve their referencibility enabling them to serve as new cross-reference benchmarks.     

An Insight into Machine Learning Algorithms to Map the Occurrence of the Soil Mattic Horizon in the Northeastern Qinghai-Tibetan Plateau

Soil diagnostic horizons, which each have a set of quantified properties, play a key role in soil classification. However, they are difficult to predict, and few attempts have been made to map their spatial occurrence. We evaluated and compared four machine learning algorithms, namely, the classification and regression tree(CART), random forest(RF), boosted regression trees(BRT), and support vector machine(SVM), to map the occurrence of the soil mattic horizon in the northeastern Qinghai-Tibetan Plateau using readily available ancillary data. The mechanisms of resampling and ensemble techniques significantly improved prediction accuracies(measured based on area under the receiver operator characteristic curve score(AUC)) and produced more stable results for the BRT(AUC of 0.921 ± 0.012, mean ± standard deviation) and RF(0.908 ± 0.013) algorithms compared to the CART algorithm(0.784 ± 0.012), which is the most commonly used machine learning method. Although the SVM algorithm yielded a comparable AUC value(0.906 ± 0.006) to the RF and BRT algorithms, it is sensitive to parameter settings, which are extremely time-consuming.Therefore, we consider it inadequate for occurrence-distribution modeling. Considering the obvious advantages of high prediction accuracy, robustness to parameter settings, the ability to estimate uncertainty in prediction, and easy interpretation of predictor variables, BRT seems to be the most desirable method. These results provide an insight into the use of machine learning algorithms to map the mattic horizon and potentially other soil diagnostic horizons.     

中国东北黑土养分空间异质性

Patterns of soil organic carbon (SOC) storage and density in various soil types or locations are the foundation for examining the role of soil in the global carbon cycle. An assessment of SOC storage and density patterns in China based on soil types as defined by Chinese Soil Taxonomy (CST) and the recently compiled digital 11000 000 Soil Database of China was conducted to generate a rigorous database for the future study of SOC storage. First, SOC densities of 7292soil profiles were calculated and linked by soil type to polygons of a digital soil map using geographic information system resulting in a 11000 000 SOC density distribution map of China. Further results showed that soils in China covered 9 281 ×103 km2 with a total SOC storage of 89.14 Gt and a mean SOC density 96.0 t ha-1. Among the 14 CST orders, Cambosols and Argosols constituted high percentage of China's total SOC storage, while Andosols, Vertosols, and Spodsols had a low percentage. As for SOC density, Histosols were the highest, while Primosols were the lowest. Specific patterns of SOC storage of various soil types at the CST suborder, group, and subgroup levels were also described. Results obtained from the study of SOC storage and density of all CST soil types would be not only useful for international comparative research, but also for more accurately estimating and monitoring of changes of SOC storage in China.     

成土作用及人为活动对水耕人为土钙镁行为的影响

The formation of Stagnic Anthrosols is closely related to rice planting and parent materials. Six representative pedons,two from each of three Stagnic Anthrosol subgroups, Vertic Haplic-, Vertic Gleyic-, and Sulfic Gleyic-Stagnic Anthrosols,from different parent materials and soil formation processes, from Liaoning Province, China, were selected and used along with additional supporting data to assess the potential impact in each soil subgroup combination of both pedogenic and anthropogenic factors on the migration and geochemical characteristics of calcium (Ca) and magnesium (Mg) and their relations to soil particle-size composition. Results revealed that exchangeable Mg was correlated positively with clay and silt content, but negatively with sand content, suggesting that clay and silt could retain more exchangeable Mg than sand. Also, in the six pedons exchangeable Ca/Mg ratios generally decreased with depth, which was most likely due to the preferential retention of Mg below the Apl horizon and the effects of bio-cycling in rice-soil systems. The pedons with high pH had smaller exchangeable Ca/Mg ratios than those with low pH. Thus, it was concluded that exchangeable Ca/Mg ratios could be helpful in classification of Stagnic Anthrosols.     

Hydrological Responses and Flow Pathways in an Acrisol on a Forested Hillslope with a Monsoonal Subtropical Climate

The nature of subsurface flow depends largely on hydraulic conductivity of the vadoze zone, permeability of the underlying bedrock, existence of soil layers differing in hydraulic properties and macropore content, soil depth, and slope angle.Quantification of flow pathways on forested hillslopes is essential to understand hydrological dynamics and solute transport patterns.Acrisols, with their argic Bt horizons, are challenging in this respect.To further elucidate flow pathways of water and short-term variability of soil moisture patterns in Acrisols, a field study was conducted on a forested hillslope in a sub-catchment of the Tie Shan Ping(TSP)watershed, 25 km northeast of Chongqing City, China.This catchment is covered by a mixed secondary forest dominated by Masson pine(Pinus massoniana).Soil saturated hydraulic conductivity(K sat) was significantly reduced at the interface between the AB and Bt horizons(2.6 × 10~(-5) vs.1.2 × 10~(-6) m s~(-1)), which led to that the flow volume generated in the Bt horizon was of little quantitative importance compared to that in the AB horizon.There was a marked decrease in porosity between the OA and AB horizons, with a further decrease deeper in the mineral subsoil.Especially, the content of soil pores 300 μm was higher in the AB horizon(14.3%)than in the Bt horizon(6.5%).This explained the difference in soil K sat values.This study showed that Bt horizon had limited water transport capability, forcing part of the infiltrated rainwater as interflow through the OA and AB horizons.Thus, the topsoil responded quickly to rainfall events, causing frequent cycles of saturation and aeration of soil pores.     

河南石灰性土壤特征及其在中国土壤系统分类中的修订研究

Calcareous soils are those soils containing layers of carbonate accumulation formed by either secondary accumulation or inheritance of CaCO3 from calcareous parent materials.These soils are widely distributed in arid,semi-arid and even some humid climate environments.However,in the Chinese Soil Taxonomy (CST,3rd version),the soils that contain large amounts of CaCO3 but do not meet requirements of Aridosols are classified as Hapli-Ustic Cambosols.This group also includes many non-calcareous soils and those soils strongly affected by secondary carbonate accumulation together with quite dissimilar soils in terms of their morphology and properties.This study was conducted to determine calcification patterns and calcic processes occurring in representative pedons of calcareous soils in northwestern Henan Province,China and to classify these soils in CST.A Calcic subgroup was proposed to add within the Hapli-Ustic Cambosols.A diagnostic key was also provided to separate this subgroup from the Typic subgroup.In this way the different calcification degrees of soils were better reflected in the classification,which should lead to more uniform interpretive groups for better soil management.     

土壤微生物多样性研究方法综述

Soil microorganisms play a central role in decomposing organic matter, in determining the release of mineral nutrients, and in nutrient cycling. Recently, extensive studies have focused on soil microbial diversity. However, understanding the diversity of this complex microbial community in the soil environment is a challenging task. Thus, it is important to master and comprehend appropriate methods for studying soil microbial diversity. Concepts of soil microbial diversity and major methods of study are briefly introduced in this paper. Then, the application of biochemical-based and molecular-based techniques in this area, and their advantages and disadvantages are evaluated. Based on recent related research, perspectives for studying microbial diversity in soils are presented.     

A combined analysis based on microbial communities and volatile organic compounds as a tool to study soil quality in an urban environment

<正>Dear Editor,Soil quality is defined as“the capacity of a soil to function,within ecosystem and land use boundaries,to sustain productivity,maintain environmental quality,and promote plant and animal health”(Doran and Parkin 1994).In this context,soil functionality is fundamental to the biosphere and is highly dependent on the associated microbiota.Soil microorganisms are relevant for terrestrial ecosystem functioning,and understanding the functional changes of the biological community i...     

关中地区塿土系统分类归属及代表土系建立

塿土是关中地区受人为长期土粪堆垫而在原土壤表层形成明显堆垫层的重要农业土壤,其分类一直备受关注.为了解塿土的成土特点及系统分类归属,选取关中地区18个典型塿土剖面,通过野外成土因素、剖面形态调查与土样分析测定,依据中国土壤系统分类方案,确定其在高级和基层分类单元归属.结果表明,供试剖面包含堆垫表层、黏化层、钙积层等9个...     

重庆市潜育水稻土发育特性和系统分类研究

以重庆市境内7个发生分类的潜育水稻土典型剖面作为研究对象,通过剖面形态特征观测和理化性质测定分析,探讨其发育特性和在中国土壤系统分类(CST)中的归属。结果表明,7个供试剖面主要位于丘陵山地下坡、坡麓以及江河沿岸一级阶地,质地多为粉壤土或粉质黏壤土,不同土壤剖面中游离铁分布有较大差异,潜育特征受到人为滞水和地下水的影响,主要出现在耕作表层和受地下水位影响的深度范围内。依据CST,7个典型剖面均具有水耕表层、人为滞水土壤水分状况、潜育特征和氧化还原特征,但1个剖面虽有水耕表层但无水耕氧化还原层而隶属潜育土土纲中的石灰简育正常潜育土亚类;其余6个剖面具有水耕表层和水耕氧化还原层而分别隶属于水耕人为土亚纲中的复钙潜育水耕人为土、铁聚潜育水耕人为土和普通潜育水耕人为土亚类,依据土族和土系划分标准,建立了5个土族和7个土系。值得注意的是,目前CST中简育正常潜育土尚没有反映人为水耕活动影响(即水耕现象)的亚类,因此可以考虑新增水耕简育正常潜育土亚类。     

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。     

湘东第四纪红色黏土发育的典型土壤在中国土壤 系统分类中的归属

选取湖南省东部地区12个由第四纪红色黏土发育的典型土壤剖面,在对其成土环境、剖面形态特征及其理化性质进行研究的基础上,按照中国土壤系统分类方案,检索出了其诊断层和诊断特性,据此确定了其在中国土壤系统分类中的归属。结果表明,供试土壤剖面包含了淡薄表层、暗瘠表层、低活性富铁层、黏化层、聚铁网纹层等10个诊断层和诊断特性,其在中国系统分类体系中的位置分别为:淋溶土、富铁土和雏形土3个土纲;湿润淋溶土、湿润富铁土和湿润雏形土3个亚纲;简育湿润富铁土、铝质湿润淋溶土和铝质湿润雏形土3个土类;暗红简育湿润富铁土、表蚀简育湿润富铁土、网纹简育湿润富铁土等6个亚类;按照土族和土系划分标准,建立了黏质高岭石型酸性热性-普通铝质湿润淋溶土等9个土族和燕塘系(43-LY01)等12个土系。研究发现:受亚热带气候影响,许多土壤剖面发生了富铁铝化过程,且由于淋溶强烈,形成了聚铁网纹层,而现行的《中国土壤系统分类检索(第三版)》还不能给出一个合适的位置,因此建议在铝质湿润淋溶土亚类中增设一个可以反映相关特性的网纹铝质湿润淋溶土亚类。     

宁夏引黄灌区灌淤土的成土特点及系统分类研究

为了解宁夏引黄灌区灌淤土的成土特点和系统分类归属,在研究区内挖掘5个典型土壤剖面,经过剖面形态观测和分层取样分析,发现灌淤土主要的成土过程是人为耕作引起的土壤熟化过程、灌溉水和地下水共同作用引起的氧化还原过程以及灌溉水泥沙沉降引起的地表物理堆垫过程,有些地方还有盐渍化过程。依据《中国土壤系统分类检索(第三版)》进行检索、鉴定,发现5个典型剖面的诊断依据有灌淤表层、肥熟表层、雏形层等诊断层和冷性土壤温度状况、石灰性和氧化还原特征等诊断特性以及钙积现象,5个典型剖面分别属于人为土土纲,旱耕人为土亚纲,灌淤旱耕人为土和肥熟旱耕人为土2个土类,斑纹灌淤旱耕人为土、灌淤肥熟旱耕人为土和普通灌淤旱耕人为土3个亚类。依据《中国土壤系统分类土族与土系划分标准》将5个剖面按照控制层段土壤颗粒大小、矿物学类型的不同,初步建立5个土族和5个土系。将典型剖面在不同分类系统中的位置进行参比研究,表明发生分类与系统分类虽然并非简单一对一的关系,但却具有优势的对应关系;5个典型剖面在发生分类中归属为灌淤土土类,在中国土壤系统分类归属中为灌淤旱耕人为土和肥熟旱耕人为土2个土类,在美国土壤系统分类中归属为Inceptisols土纲,Ustepts亚纲和Haplustepts土类;相比之下,发生分类和美国土壤系统分类较为稳定,定量化的中国土壤系统分类分异性较大,使分类更加全面、细化。     

新疆典型干旱土和盐成土的系统分类归属

以新疆维吾尔自治区17个典型干旱土和盐成土的代表性单个土体作为本文研究对象,基于剖面形态特征和理化性质的分析,确定在中国土壤系统分类(CST)中的归属.研究过程中发现CST对于干旱表层的判定条件与盐积正常干旱土的定义有矛盾之处,致使分类时将一些含有盐积层的土壤划归到干旱土中,从而使干旱土扩大,盐成土减少,不利于盐成土的...     

安徽宣郎广岗丘区土壤发生分类类型在系统分类中的归属

对宣郎广岗丘地区40个土壤剖面,按中国土壤系统分类体系,进行鉴别、检索、分类定名。阐述土壤发生分类体系的11个亚类级土壤类型在中国土壤系统分类中归为5个土纲,即人为土、富铁土、淋溶土、雏形土和新成土;5个亚纲,即水耕人为土、湿润富铁土、湿润淋溶土、湿润雏形土和正常新成土;15个土类和23个亚类。参比关系复杂,不是简单的一对一的关系。提出按中国土壤系统分类的该区土壤分类系统;并讨论了该区土壤发生分类与系统分类之间具体土壤类型的对应关系。研究结果对土壤类型的正确参比、中国土壤系统分类的应用与发展、具有很好的参考应用价值。     

岷江上游杂谷脑河谷土壤发生特征与系统分类研究

为了解岷江上游杂谷脑河谷的土壤发生特征及类型归属,以位于四川阿坝藏族羌族自治州理县杂谷脑河谷的8个典型土壤剖面为研究对象,通过野外成土因素调查与土壤形态特征观测及室内土壤物理、化学性质分析,依据《中国土壤系统分类检索(第三版)》(简称系统分类)与《中国土壤(1998)》(简称发生分类)鉴定其类型。研究表明,8个剖面均为温性土壤温度状况、半干润土壤水分状况;土壤色调为7.5YR和10YR,部分剖面表层明度和彩度均低于3.5,达到暗沃表层的颜色要求;土壤颗粒组成以粉粒含量最高、砂粒次之、黏粒最低,质地为壤土或粉质壤土;土壤结构主要为亚角块状,部分剖面表层为团粒结构;部分剖面中具有腐殖质、黏粒胶膜及假菌丝体等新生体,形成黏化层和钙积层;均具石灰性,主要为碱性到强碱性反应;有机碳含量范围1.64～61.45 g/kg,部分剖面含量自上而下逐渐降低,具有均腐质特性;游离铁含量为10.78～19.57 g/kg,个别剖面B层均在14 g/kg以上,具有铁质特性;有效磷含量为1.2～43.1 mg/kg,个别符合肥熟表层和磷质耕作淀积层的有效磷含量要求。供试土壤在中国土壤系统分类中归属于人为土、均腐...     

广西岩溶地区水稻土发生特性及其在中国土壤系统分类中的归属

为明确广西岩溶地区水稻土在中国土壤系统分类中的归属，以该区域不同母质发育的水稻土为研究对象，挖掘20个典型剖面，通过野外观测、分层取样与分析，依据《中国土壤系统分类检索（第三版）》进行分类检索。结果表明，大多剖面出现明显的复钙现象。供试剖面的系统分类高级单元归属为人为土土纲，水耕人为土亚纲，潜育、铁聚和简育水耕人为土3个土类，复钙、铁聚和普通潜育水耕人为土、复钙和普通铁聚水耕人为土、复钙和普通简育.水耕人为土7个亚类，在系统分类基层单元归属上，可划归出17个土族和续分为20个土系。考虑广西地区水耕人为土耕作层Ap1碳酸钙相当物含量往往低于犁底层Ap2的现象，而现行水耕人为土复钙亚类的检索中“表层土壤”的“表层”不尽明确而可能导致的亚类误判，建议将其修改为“水耕表层（耕作层或犁底层）土壤”；另外，由于实际调查发现广西地区的一些铁聚水耕人为土也具有复钙特征，建议在检索中增设复钙铁聚水耕人为土亚类。     

河北省秦皇岛市石门寨区域土壤系统分类

为推广应用中国土壤系统分类 ,本文对自然地理野外实习基地—河北省秦皇岛市石门寨区域的土壤进行系统分类研究。结果如下 :土壤诊断层有淡薄表层、水耕表层、雏形层、水耕氧化还原层、粘化层 ,诊断特性有砂质沉积物岩性特征、石质接触面、半干润土壤水分状况、湿润土壤水分状况、人为滞水土壤水分状况、氧化还原特征、冷性土壤温度状况、温性土壤温度状况 ,土壤类型归属为人为土纲、淋溶土纲、雏形土纲和新成土纲。并与原土壤地理发生分类进行参比及总结地理分布规律