Simple Soil Classification

Soil Classification

1. Refers to grouping soil based on specific characteristics such as texture, climate, age, and color.
2. One common classification is based on soil texture.
3. According to the soil texture triangle, soils can be classified into three main textures: sand, silt, and clay.

Soil Texture Triangle

1. Sand

   • Composed mainly of coarse and fine sand with minimal clay.
   • Not sticky when wet and loose when dry.
   • Sand content: above 85%, Clay: up to 10%, Silt: up to 10%.
   • When rubbed, it doesn't leave a film on the fingers.

2. Loamy Sand

   • Mainly sand with sufficient clay to give it slight plasticity when moist.
   • When rubbed, it leaves a slight film of fine material.
   • Sand content: 70%-90%, Clay: up to 15%, Silt: up to 30%.

3. Sandy Loam

   • Has high sand content (43%-85%) and low clay content (up to 20%).
   • Molds easily when sufficiently moist but doesn't stick easily to fingers.
   • Sand content: 43%-85%, Clay: up to 20%, Silt: up to 50%.

4. Loam

   • Sand and silt dominate (about 40% each), with clay content around 20%.
   • Molds easily when moist and sticks to fingers to some extent.
   • Sand content: 40%, Silt: 40%, Clay: 20%.

5. Silt Loam

   • High silt content (50%-87%) and moderate sand (13%-50%) and clay (up to 27%).
   • Moderately plastic and smooth, with a soapy feeling due to the high silt content.

6. Sandy Clay Loam

   • Over 45% sand, up to 28% silt, and clay between 20%-35%.
   • Somewhat sticky due to the clay but still porous due to sand.

7. Clay Loam

   • Sand content between 20%-54%, silt between 15%-53%, clay between 27%-40%.
   • Sticky when moist due to high clay content.

8. Silt Clay Loam

   • Sand content between 27%-60%, silt between 40%-78%, and clay between 27%-40%.
   • Smooth with a soapy feel, less sticky than clay loam or silt clay.

9. Silt

   • Contains over 80% silt, up to 20% sand, and less than 12% clay.
   • Predominantly smooth with a soapy feeling of silt.

10. Sandy Clay

    • Sand content between 45%-65%, silt up to 20%, and clay between 35%-55%.
    • Plastic and sticky when moist due to clay and sand dominance.

11. Clay

    • Sand content up to 45%, silt up to 20%, and clay above 40%.
    • Sticky when moist, has a plastic feel, and can be molded into threads or shapes.

12. Silt Clay

    • Sand content up to 20%, silt between 40%-60%, and clay between 40%-60%.
    • Fine particles throughout, smooth with a soapy feel, but sticky due to high clay content.