Water holding capacity of the soil depends upon

Options

A. chemical composition of soil
B. particle size of soil
C. aggregation of soil particles
D. all of these

Explanation

To answer the question regarding the factors that affect the water holding capacity of soil, we can break down the solution into several steps:

### Step-by-Step Solution:

1. **Understanding Water Holding Capacity**:
- Water holding capacity refers to the amount of water that soil can retain for use by plants. This is crucial for plant growth and overall ecosystem health.

2. **Identifying Key Factors**:
- Several factors influence the water holding capacity of soil. These include:
- **Chemical Composition**: The types of minerals and ions present in the soil can affect its ability to retain water.
- **Particle Size**: The size of the soil particles (sand, silt, clay) plays a significant role in determining how much water the soil can hold.
- **Soil Aggregation**: The way soil particles clump together affects the formation of pores, which are essential for water retention.

3. **Analyzing Each Factor**:
- **Chemical Composition**: Soils rich in certain minerals may have better water retention properties due to their chemical structure.
- **Particle Size**: Smaller particles (like clay) have a greater surface area and can hold more water compared to larger particles (like sand).
- **Soil Aggregation**: Well-aggregated soils create more pore spaces, which can trap water through capillary action.

4. **Conclusion**:
- All three factors—chemical composition, particle size, and soil aggregation—are crucial in determining the water holding capacity of soil. Therefore, the water holding capacity of soil depends on these characteristics.

### Final Answer:
The water holding capacity of the soil depends on:
- Chemical composition
- Particle size
- Soil aggregation