Question

Which land capability classes are divided into sub classes for agriculture use on the basis of
I. risk of erosion or post erosion damage
II. wetness
III. damage or overflow
IV. root zone limitation
V. climatic limitation
Choose the correct answer from the options given below:

• A. I, II, IV
• B. III, IV, V
• C. II, III, IV
• D. I, II, III

Hint:

To remember the land capability subclasses, memorize the acronym "wesc":
- w: Wetness
- e: Erosion
- s: Soil/Root-zone
- c: Climate
Class I land is ideal and has no subclasses.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The USDA Land Capability Classification system groups soils based on their suitability for various uses, particularly agriculture.
The system consists of eight land capability classes (I to VIII).
Classes II through VIII are further divided into subclasses to identify specific conservation limitations.
Detailed Explanation:
The land capability classification system uses four primary subclasses to represent specific hazards or limitations:
1. Subclass e (Erosion): Used when the land is susceptible to erosion or has suffered past erosion damage (matches Statement I).
2. Subclass w (Wetness): Used where excess water, high water tables, or poor drainage is the primary hazard (matches Statement II).
3. Subclass s (Soil/Root Zone): Used when the soil is shallow, stony, low in water-holding capacity, or has root-zone limitations (matches Statement IV).
4. Subclass c (Climate): Used where climate (extreme cold or dryness) is the main limitation.
Let us review the statements:
- Statement I (erosion), Statement II (wetness), and Statement IV (root-zone limitation) correspond to the three most common subclasses (e, w, s).
- Statement III (damage or overflow) is typically considered a sub-hazard within the broader wetness (w) subclass rather than a standalone category.
Therefore, the primary subclasses are represented by I, II, and IV.

Step 2: Final Answer:
The land capability subclasses are designated based on the hazards represented by I, II, and IV.