International classification standard of soil particles (up to subclasses) and classification of various soil particles.

International classification standard of soil texture

Texture name clay (

Loam sand 0 ~150 ~1585 ~100

Sandy loam 0 ~ 150 ~ 455585

Soil 0~ 15 30~45 40~55

Silty loam 0~ 15 45~ 100 0~55

Sandy clay loam 15~25 0~30 55~85

Clay loam 15~25 20~45 30~55

Silty loam 15~25 45~85 0~40

Sandy clay 25~45 0~20 55~75

Clay 25~45 0~45 10~55

Silty clay 25~45 45~75 0~30

Clay 45~65 0~55 0~55

In the composition of soil particles, the soil with > 2mm gravel exceeding 1% is classified as gravelly soil or gravelly soil according to the gravel content.

When describing soil texture, gravel soil is preceded by the word "soil-forming", such as gravel sand and less gravel sand. Gravel content of less gravel soil is1~ 5%; Gravel content of medium gravel soil is 5 ~10%; Gravel content of gravelly soil is 10~30%.

Gravel soil. When the gravel content in the soil exceeds 30%, according to the regulations, the names of fine parts are no longer recorded, but only one kind of gravel soil is indicated. The grading standard is: light gravel soil with gravel content of 30~50%; 50~70% is medium gravel soil; More than 70% is heavy gravelly soil. According to the inspection, the material situation of the fine part of gravel is different, and the reaction in production is also very different. Therefore, in the indoor test, the particle composition of the fine-grained part is still determined separately, and the overall texture is still named gravel soil, but the texture name of the fine-grained part is expressed in brackets. For example, the gravel content of soil A > 2mm is 65%, and the fine-grained part is loam. When finally named, it is defined as medium gravel soil (loam).