Understanding Soil Texture Classification Quiz

Study Notes

Soil Classification

Soils can be classified into 12 textural classes or grades, including sand (85% sand or more), loamy sand (75-85% sand), coarse-textured soils, sandy loam (43-52% sand), loam (less than 52% sand, 7-27% clay, 28-50% silt), silt loam (less than 50% silt), medium-textured soils, clay loam soils, sandy clay loam, silty clay loam, sandy clay, and fine-textured soils.

Soil Texture Determination

Soil texture can be determined in three ways: by feel method, roll method, and by mechanical analysis.
The feel method involves rubbing moist soil between the fingers to estimate the characteristic "feel" of the dominant soil separate.
The roll method involves kneading a moist soil sample into a rod to approximate the soil texture.
Mechanical analysis is a more accurate method that involves separating soil particles into different size fractions.

Soil Properties

Soil properties can be classified into three categories: physical, chemical, and biological.
Physical properties of soils include soil texture, color, consistency, temperature, structure, densities and porosity, and water/soil moisture and aeration.

Soil Separates

Soil particles can be grouped into three soil separates: sand, silt, and clay.
Each separate has a specific range of particle sizes, and they are often referred to as fractions (e.g., sand fraction, silt fraction, or clay fraction).
The characteristics of each separate affect the overall properties and behavior of the soil.

Characteristics of Soil Separates

Sand: low water-holding capacity, good aeration, high drainage rate, low compactibility, and low surface area.
Silt: medium to high water-holding capacity, moderate aeration, slow to medium drainage rate, medium compactibility, and medium surface area.
Clay: high water-holding capacity, poor aeration, very slow drainage rate, high compactibility, and high surface area.

Description

Test your knowledge on soil texture classification including sand, silt, and clay percentages in various textural classes. Learn about different soil types like loamy sand, sandy loam, silt loam, and clay loam. Explore methods for determining soil texture.