What does the term "silt" refer to?

The term "silt" refers to a type of soil that consists of very fine particles, which are larger than clay but smaller than sand. This fine texture allows silt to retain moisture and nutrients effectively, making it ideal for agricultural use. Silt often comes from the natural erosion of rocks and minerals and is commonly found in sedimentary deposits near rivers and lakes.

In contrast, other options do not accurately define silt. For instance, while water pollution and soil conservation are important environmental topics, they do not pertain to the geological composition and characteristics of silt. Similarly, hardened clay represents a different soil type entirely, with distinct properties and uses compared to silt. Understanding silt's role in soil composition is crucial for topics related to agriculture, ecology, and earth sciences.