Which of the following soils shows cracks and shrinks most when it dries?

Options

A. Porous soil
B. Clay soil
C. Loam soil
D. Sandy soil

Answer

To determine which type of soil shows cracks and shrinks the most when it dries, we can analyze the properties of the different soil types mentioned in the question:

1. **Understanding Soil Types**:
- **Porous Soil**: This type of soil has spaces between particles that allow air and water to move through easily. It does not typically shrink or crack significantly when drying.
- **Clay Soil**: Clay soil consists of very fine particles that are tightly packed. When it dries, it tends to shrink and can develop significant cracks due to its high shrink-swell capacity.
- **Loam Soil**: Loam is a mixture of sand, silt, and clay. It has good drainage and nutrient-holding capacity but does not shrink as much as clay soil when it dries.
- **Sandy Soil**: Sandy soil has larger particles and drains quickly. It does not retain moisture well and does not typically shrink or crack significantly when it dries.

2. **Analyzing Shrink-Swell Capacity**:
- The shrink-swell capacity of soil refers to its ability to expand when wet and shrink when dry. Clay soil has a high shrink-swell capacity due to its fine particles and the way they interact with water.

3. **Conclusion**:
- Based on the properties of these soils, clay soil is the one that shows the most significant cracking and shrinking when it dries. The fine particles of clay soil pull apart as moisture is lost, leading to the formation of cracks.

Thus, the answer to the question is **clay soil**.