What is the term used to identify the top layer of the earth's surface that is suitable for plant growth?

The term that identifies the top layer of the earth's surface that is suitable for plant growth is topsoil. This layer contains a rich mixture of organic matter, nutrients, and minerals that support plant life.

Topsoil is critical for agriculture because it serves as the primary medium for growing crops, and it holds moisture and nutrients essential for plant development. The organic material in topsoil, which consists of decomposed plant and animal matter, enhances soil fertility and structure, making it conducive for root growth and microbial activity.

In contrast, subsoil is located beneath the topsoil and generally contains fewer nutrients and organic matter, making it less suitable for plant growth. Bedrock is the solid layer of rock beneath the soil layers and does not support vegetation directly. Silt, while it is one of the components of soil, especially in topsoil, refers to the size and texture of soil particles rather than a specific layer of soil. Therefore, topsoil is the correct term for the layer most directly responsible for supporting plant growth.