矿质土粒( soil particle) 二)土粒概念 soil particle 土粒sei| particle:土壤中各种粒径的固相颗粒 依据存在的状态: 依据粒径大小 单粒:sing| e particle (单粒) 复粒: compound particle (三)土壤粒级 particle sizes 1.粒级概念( fraction):土壤颗粒的大小分级 2.粒级划分依据:粒级化分的表观依据(或依赖的指标):依 据单个颗粒的粒径大小进行。 那么土壤颗粒的粒径有何实际含义(?),颗粒的形状(?)
一.矿质土粒 （soil particle） （二）土粒概念 soil particle 土粒 soil particle：土壤中各种粒径的固相颗粒 依据存在的状态： 单粒：single particle 复粒：compound particle 依据粒径大小 （单粒） （三）土壤粒级 particle sizes 1.粒级概念（fraction)：土壤颗粒的大小分级 2.粒级划分依据：粒级化分的表观依据（或依赖的指标）：依 据单个颗粒的粒径大小进行。 那么土壤颗粒的粒径有何实际含义（？），颗粒的形状（？）
矿质土粒( soil particle) 土壤颗粒绝非标准球形,是各种不规格形状的,那么,粒径的 含义就并非它们的真实直径或半径。---当量直径 当量直径(有效直径) equivalent diameter or effective diameter of soil particle:与同质的标准球形颗粒沉降速度相同的土粒直径 或半径(建立在颗粒分析方法上) 3.粒级分类制( classification systems of soil separates) 土壤颗粒大小是连续分布的,要确定土壤颗粒的分级需要硏究土壤颗粒大小 和性状间关系,找到由量变到质变分界点,突变点,就可以作为化分类别的依 据。受人为因素的影响,当前土壤立即分类制有: Size is a continuous variable. Although dividing particle size into discrete size ranges is arbitrary, it is also useful. Individual soil particles range in size from boulders that are meters in diameter to clay particles that are less than 0.002mm(less than 2 um) in diameter Particles so different in size also have different properties. The terms used to divide the continuous size variable diameter into discrete units are considered next
一.矿质土粒 （soil particle） 土壤颗粒绝非标准球形，是各种不规格形状的，那么，粒径的 含义就并非它们的真实直径或半径。-----当量直径 当量直径（有效直径）equivalent diameter or effective diameter of soil particle : 与同质的标准球形颗粒沉降速度相同的土粒直径 或半径（建立在颗粒分析方法上） 3. 粒级分类制（classification systems of soil separates) 土壤颗粒大小是连续分布的，要确定土壤颗粒的分级需要研究土壤颗粒大小 和性状间关系，找到由量变到质变分界点，突变点，就可以作为化分类别的依 据。受人为因素的影响，当前土壤立即分类制有： Size is a continuous variable .Although dividing particle size into discrete size ranges is arbitrary, it is also useful. Individual soil particles range in size from boulders that are meters in diameter to clay particles that are less than 0.002mm (less than 2 m）in diameter .Particles so different in size also have different properties. The terms used to divide the continuous size variable, diameter, into discrete units are considered next
土壤粒级分类系统(三级分类制) classification systems of soil separates 国际制(SSS 美国制(USDA) 苏联制 International Soil Science Society U.S Department of agriculture KayMHCKnn (1930) Atterberg(1912) (1956) (1965) 粒级名称 粒径/mm 粒级名称 粒径/mm 粒级名称 粒径/mm 石块 stone .0 石块 kameHCTBs 石砾 gravel 粗砾 gravel 2-3 石砾 paiN 极粗砂粒 ery coarse 1~2 sand 粗细砂 neco 粗砂 coarse sand2-0.2粗砂粒 coarse sand 细砂 fine sand 0.2~002中砂粒 medium sand 0.25~0.5 中细砂 ecok cpeAHI 0.25~0.5 细砂粒 fine sand 0.1~0.25 细砂粒∏ ecok MenKe 0.05~0.02 极细砂粒 very fine sand 0.05~0.1 粗粉砂 lbInb kpynHag 0.01~0.05 粉粒sit .002 粉粒sit 0.002-0.05中粉砂门 Ib cpeAHas 0.005~0.0 细粉砂 TbInb Menka9 0.001~0.005 粘粒 wn rnMHNCTblM 0.005~0.001 粘粒cay <0002 粘粒cay <0.002 胶粒 wn konnowAHbln00001-005 胶体 Konoha <0.0001
土壤粒级分类系统(三级分类制) classification systems of soil separates 国际制(ISSS) International Soil Science Society (1930) Atterberg(1912) 美国制(USDA) U.S Department of agriculture (1956) 苏联制 Качинский (1965) 粒级名称 粒径/mm 粒级名称 粒径/mm 粒级名称 粒径/mm 石砾 gravel >2 石块 stone 粗砾 gravel >3.0 2~3 石块каменствя 石砾гравий >3 1~3 粗砂 coarse sand 细砂 fine sand 2~0.2 0.2~0.02 极粗砂粒 very coarse sand 粗砂粒 coarse sand 中砂粒 medium sand 细砂粒 fine sand 极细砂粒very fine sand 1~2 0.5~1 0.25~0.5 0.1~0.25 0.05~0.1 粗细砂 Песок крупный 中细砂Песок средний 细砂粒 Песок мелкий 0.5~1 0.25~0.5 0.05~0.02 粉粒 silt 0.02~0.002 粉粒 silt 0.002~0.05 粗粉砂Пыль крупная 中粉砂Пыль средная 细粉砂Пыль мелкая 0.01~0.05 0.005~0.01 0.001~0.005 粘粒 clay <0.002 粘粒 clay <0.002 粘粒 ил глинистый 胶粒ил коллоидный 胶体 коллоид 0.005~0.001 0.0001~0.0005 <0.0001
- SAND SILT clay Relative sizes of sand, silt, and clay
Soil Properties: Texture Soil Texture: The relative proportions of sand, silt, and clay particles in a mass of soil (material less than 2mm in size) Very Coarse Sand =2 to 1 mm Very Fine Sand =0. 1 to 0.5 mm Silt=0.05 to 0.002 mm Clay =<0.002 mm