Question

Arrange the following in increasing order of their sand content
A. Sandy soil
B. Silty Soil
C. Clayey soil
D. Loamy soil
Choose the correct answer from the options given below:

• A. C, D, B, A
• B. C, B, D, A
• C. A, D, B, C
• D. B, C, D, A

Hint:

Sand Content Hierarchy:
Clay ($< 20\%$) $<$ Silt ($10-20\%$) $<$ Loam ($40-50\%$) $<$ Sand ($> 70-85\%$).
Clay holds water best because it has the lowest sand and finest pore spaces, while sandy soil drains rapidly due to its dominant coarse sand content.

Answer 1

The Correct Option is B

Concept:
Soil texture is defined by the relative proportions of three primary mineral size separates: sand (coarse, $0.05$ to $2.0\text{ mm}$), silt (medium, $0.002$ to $0.05\text{ mm}$), and clay (colloidal, $< 0.002\text{ mm}$).
Soil classification schemes (such as the USDA textural triangle) delineate soil textural classes based on the relative weight percentages of these three mineral components.

Step 1: Quantitative Evaluation of Sand Percentage in Major Soil Classes:
1. Clayey Soil (C): Dominated by fine, cohesive clay colloids ($> 40-50\%$ clay content). Its sand content is typically the lowest among major classes, generally remaining below $15-20\%$ by weight.
2. Silty Soil (B): Dominated by silt particles ($> 80\%$ silt). Sand particles typically constitute only about $10-20\%$ of pure silt soils.
3. Loamy Soil (D): An agricultural soil blend comprising approximately equal influence of sand, silt, and clay. A standard loam contains approximately $40-50\%$ sand, $30-40\%$ silt, and $10-20\%$ clay.
4. Sandy Soil (A): Characterized by high porosity, low water-holding capacity, and large particle diameters. By definition, sandy soil consists of at least $70-85\%$ sand particles by weight.

Step 2: Arranging in Increasing Order (Lowest to Highest):
Ordering the soils by increasing sand fraction:
\[ \text{Clayey soil (C)} < \text{Silty soil (B)} < \text{Loamy soil (D)} < \text{Sandy soil (A)} \] This yields the sequence: C, B, D, A.
Final Answer:
The correct increasing order of sand content is C, B, D, A, which corresponds to option (B).