Question

In the USDA soil classification system, fine sand has a size range of:

• A. 2.0 - 0.50 mm
• B. 0.50 - 0.25 mm
• C. 0.25 - 0.10 mm
• D. 0.10 - 0.05 mm

Hint:

International Society of Soil Science (ISSS) limits differ from USDA. In ISSS, Fine Sand is 0.20 - 0.02 mm. Always check which system the question is referring to.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The United States Department of Agriculture (USDA) uses a specific standardized system to classify soil particles based on their effective diameter.
Soil separates are divided into sand, silt, and clay, with sand further subdivided into five size classes.

Step 2: Detailed Explanation:
The USDA classification for sand particles is as follows:
1. Very Coarse Sand: 2.0 mm to 1.0 mm
2. Coarse Sand: 1.0 mm to 0.50 mm
3. Medium Sand: 0.50 mm to 0.25 mm
4. Fine Sand: 0.25 mm to 0.10 mm
5. Very Fine Sand: 0.10 mm to 0.05 mm
Particles smaller than 0.05 mm but larger than 0.002 mm are classified as Silt, and particles smaller than 0.002 mm are classified as Clay.
This classification is essential for determining soil textural classes using the textural triangle. Fine sand provides a balance between drainage and moisture retention compared to coarse sand.

Step 3: Final Answer:
Based on the standard USDA particle size limits, fine sand falls in the range of 0.25 mm to 0.10 mm.