Which of the following is true for horizon A

Options

A. soil ligh in colour than C horizon
B. microbial activity is lesser
C. presence of different stages of decompostion of organic matter
D. weathered matter has not become true soil

Answer

To determine which statement is true for horizon A, we need to analyze each option provided in the question. Horizon A, also known as the topsoil layer, has specific characteristics that we can evaluate.

### Step-by-Step Solution:

1. **Understanding Horizon A**:
- Horizon A is the top layer of the soil profile and is commonly referred to as topsoil. It is crucial for plant growth as it contains essential nutrients.

2. **Evaluating the Options**:
- **Option 1**: "Soil light in color than sea origin."
- This statement is misleading. Horizon A is typically darker due to the presence of organic matter (humus).

- **Option 2**: "Microbial activity is lesser."
- This is incorrect. Horizon A is rich in organic matter and supports a high level of microbial activity, which is essential for decomposition and nutrient cycling.

- **Option 3**: "Presence of different stages of decomposition of organic matter."
- This statement is true. Horizon A contains various stages of decomposed organic matter, primarily in the form of humus, which is crucial for soil fertility.

- **Option 4**: "Weathering matter has not become the true soil."
- This statement is misleading as well. Horizon A is indeed considered true soil, as it has developed from weathering processes and organic accumulation.

3. **Conclusion**:
- The correct answer is **Option 3: "Presence of different stages of decomposition of organic matter."** This accurately describes the characteristics of horizon A.