、美国土壤分类系统 美国土壤糸统分类是一个六级土壤分类糸统,根据土 壤性态概括程度的大小,由上而下分为土纲、亚纲、大土类 亚类、土族和土糸等六级。土糸之下还可划分出土相。 序号 土纲 字根 索 有机土( Histosols ist 土表具有机表层者 灰±( Spodosols) 2米深以内可见灰化淀积层者 3火让灰士( Andisols)and具有火山灰土壤性质者 氧化土(0 isola) 2米内有氧化层、无粘化层者 变性土( entisols)ert各层粘粒含量09%,60厘米土层干时开裂者 千旱土( Aridisols) 具有干旱水分状况,有一淡色表层等者 7老成土(Utio1s) lf 有粘化层或高岭层者,且在1.8米处盐基饱和度<35赌 8软(Moi1l)1t有松软表层者 淋溶土(A1 fisola) lf有化层、高岭层或碱化层者 10始成士( Inceptisol1s)ept 有雏形层等者 新成土( Entiso1a) 其它土壤
三、美国土壤分类系统 美国土壤系统分类是一个六级土壤分类系统，根据土 壤性态概括程度的大小，由上而下分为土纲、亚纲、大土类、 亚类、土族和土系等六级。土系之下还可划分出土相
三、美国土壤分类系统 命名方法 美国土壤糸统分类的土壤分类单元名称釆用了拉丁文及希腊文词根拼 缀法,实际上是一种连塽命名法。它是以土纲名称的字根为基础,累加 糸列形容词或副词,分别顺次构成了正纲、土类、正类、土族的名称。 例如( Clayey loamy Mixed thermic, Typic paleudults(粘壤质,混合 物的,热性的,典型的强发育湿润老成土土属),其中ut为 Ultisols(老 成土)的字根;叫表明该亚纲的土壤水分状况为湿涧的(Udic),其亚纲 为浞润老成土;Pale表示该土壤的粘化层发育度高、深厚,为土类的修 饰词,其土类为强发育湿润老成土; Typic为正类的修饰词,代表典型的, 其正类为典型的强发育湿涧老成土; Clayey loamy(粘壤的)、 Mixed 矿物混合的)、 thermic(温度为热性的)均为土族的修饰词。由此 可见,豕用这种方法命名,可以从土壤名称上联想到该土壤的属性及每 一个分类单元划分上所采用的土壞性质。在糸统分类中,土糸按土壤首 次发现肘的地名(城镇)命名,在宅后带上表土层质地类别。美国对其 国内已确定的土糸都分别作了档案,并有较详细的记载
三、美国土壤分类系统 命名方法 美国土壤系统分类的土壤分类单元名称采用了拉丁文及希腊文词根拼 缀法，实际上是一种连续命名法。它是以土纲名称的字根为基础，累加 一系列形容词或副词，分别顺次构成了亚纲、土类、亚类、土族的名称。 例如Clayey loamy Mixed thermic, Typic paleudults （粘壤质，混合矿 物的，热性的，典型的强发育湿润老成土土属），其中ult为Ultisols(老 成土)的字根；ud表明该亚纲的土壤水分状况为湿润的(Udic)，其亚纲 为湿润老成土；Pale表示该土壤的粘化层发育度高、深厚，为土类的修 饰词，其土类为强发育湿润老成土；Typic为亚类的修饰词,代表典型的， 其亚类为典型的强发育湿润老成土；Clayey loamy（粘壤的）、Mixed （矿物混合的）、thermic（温度为热性的）均为土族的修饰词。由此 可见，采用这种方法命名，可以从土壤名称上联想到该土壤的属性及每 一个分类单元划分上所采用的土壤性质。在系统分类中，土系按土壤首 次发现时的地名（城镇）命名，在它后带上表土层质地类别。美国对其 国内已确定的土系都分别作了档案，并有较详细的记载
四、中国土壤系统分类 诊断层( diagnostic horizon)和诊断特性( diagnosis features) 中国土壤糸统分类也是以诊断层和诊新特性为基础的糸统化、定量化的土 壤分类。该糸统分类中共设立了11个诊新表层,20个诊新表下层,2个其他诊 断层和25个诊新特性。 11个诊新层为:有机表层、草毡表层、暗沃表层、暗瘠表层、淡薄表层 灌淤表层、堆垫表层、肥熟表层、水耕表层、干旱表层和盐结壳。 20个诊断层表下层为:漂白层、舌状层、雏形层、铁铝层、低活性富铁层 聚铁网纹层、灰化淀积层、耕作淀积层、水耕氧化还原层、粘化层、粘磐 碱积层、超盐积层、盐磐、石膏层、超石膏层、钙积层、超钙积层、钙磐和 磷磐。 其它诊新层包括盐积层和含硫层。 25个诊新特性为:有机土壤物质、岩性特征、石质接触面、准石质接触面 人为淤积物质、变性特征、人为扰动层次、土壤水分状况、潜育特征、氣化 还原特征、土壤温度状汎、永冻层次、冻融特征、η值、均腐殖质特性、腐殖 质特性、火山灰特性、铁质特性、富铝特性、铝质特性、富磷特性、钠质特 性、石灰性、盐基饱和度及硫化物物质
四、中国土壤系统分类 诊断层（diagnostic horizon)和诊断特性(diagnosisfeatures ) 中国土壤系统分类也是以诊断层和诊断特性为基础的系统化、定量化的土 壤分类。该系统分类中共设立了11个诊断表层，20个诊断表下层，2个其他诊 断层和25个诊断特性。 11个诊断层为：有机表层、草毡表层、暗沃表层、暗瘠表层、淡薄表层、 灌淤表层、堆垫表层、肥熟表层、水耕表层、干旱表层和盐结壳。 20个诊断层表下层为：漂白层、舌状层、雏形层、铁铝层、低活性富铁层、 聚铁网纹层、灰化淀积层、耕作淀积层、水耕氧化还原层、粘化层、粘磐、 碱积层、超盐积层、盐磐、石膏层、超石膏层、钙积层、超钙积层、钙磐和 磷磐。 其它诊断层包括盐积层和含硫层。 25个诊断特性为：有机土壤物质、岩性特征、石质接触面、准石质接触面、 人为淤积物质、变性特征、人为扰动层次、土壤水分状况、潜育特征、氧化 还原特征、土壤温度状况、永冻层次、冻融特征、n值、均腐殖质特性、腐殖 质特性、火山灰特性、铁质特性、富铝特性、铝质特性、富磷特性、钠质特 性、石灰性、盐基饱和度及硫化物物质
主要诊断层( diagnostic horizon) 1 Diagnostic Epipedon(诊断表层)- The Surface soil The upper surface of a soil is the boundary between the soil and air, shallow water live plants, or plant materials that have not begun to decompose The epipedon is a horizon that forms at or near the surface. It is darkened by organic matter or shows evidence ofeluviation. An epipedon is not the same as an a horizon The epipedon may include part or all of an illuvial b horizon if the darkening by organic matter extends from the soil surface into the b horizon all soils must have one of the following epipedon Eight epipedon are recognized but only six occur naturally. The anthropic and plaggen are the result of intensive human use Mollic epipedon(松软表土层): The mollic is a dark, colored mineral horizon. It is thick(generally> 25 cm)and has a high base status(>50% base saturation ). These epipedon are characteristic of soils developed under native prairie(湿草原土壤) --mellic Umbric epipedon(暗色表层): The umbric has the same characteristics as the mollic except the %base saturation is less than 50% due to leaching of basic cations. The umbric develops in areas with higher rainfall than the mollic e soil
主要诊断层（diagnostic horizon) 1.Diagnostic Epipedons （诊断表层）-The Surface Soil The upper surface of a soil is the boundary between the soil and air, shallow water, live plants, or plant materials that have not begun to decompose. The epipedon is a horizon that forms at or near the surface. It is darkened by organic matter or shows evidence of eluviation. An epipedon is not the same as an A horizon. The epipedons may include part or all of an illuvial B horizon if the darkening by organic matter extends from the soil surface into the B horizon. All soils must have one of the following epipedons Eight epipedons are recognized but only six occur naturally. The anthropic and plaggen are the result of intensive human use. Mollic Epipedon（松软表土层）:The mollic is a dark, colored mineral horizon. It is thick (generally > 25 cm) and has a high base status ( > 50% base saturation). These epipedons are characteristic of soils developed under native prairie（湿草原土壤）. Umbric Epipedon（暗色表层）:The umbric has the same characteristics as the mollic except the % base saturation is less than 50% due to leaching of basic cations. The umbric develops in areas with higher rainfall than the mollic
主要诊断层( diagnostic horizon) Melanic epipedon(黑色表士层): The melanic epipedon is a mineral horizon that is very black in color due to its high organic matter content It is characteristic of soils developed from volcanic ash(火山灰) Histic epipedon(泥炭层): The histic epipedon is a layer of organic soil that is naturally saturated with water Folistic epipedon: The folistic epipedon is like the histic except it is not saturated with water for more than 30 days Ochric epipedon(淡色表层): The ochric fails to meet the definitions for any of the other epipedon. Thus it is too light too thin or too low in organic matter. If a soil's epipedon does not meet any of the criteria for the other seven epipedon than it is ochric
主要诊断层（diagnostic horizon) Melanic Epipedon(黑色表土层): The melanic epipedon is a mineral horizon that is very black in color due to its high organic matter content. It is characteristic of soils developed from volcanic ash （火山灰）. Histic Epipedon （泥炭层）: The histic epipedon is a layer of organic soil that is naturally saturated with water. Folistic Epipedon: The folistic epipedon is like the histic except it is not saturated with water for more than 30 days. Ochric Epipedon（淡色表层）: The ochric fails to meet the definitions for any of the other epipedons. Thus it is too light, too thin or too low in organic matter. If a soil's epipedon does not meet any of the criteria for the other seven epipedons than it is ochric