What is the uppermost layer of soil that is the most fertile called?

The uppermost layer of soil that is the most fertile is called topsoil. This layer is rich in organic material and nutrients, making it essential for plant growth. Topsoil typically contains a mixture of minerals, decomposed plant and animal matter, and living organisms such as bacteria and earthworms, all of which contribute to its fertility.

Topsoil serves as the primary layer where seeds germinate and roots develop, enabling plants to thrive. Its rich nutrient content supports agricultural practices and is crucial for sustainable farming. Understanding the characteristics of topsoil helps in implementing effective soil management practices, ensuring that crops receive the necessary nutrients for growth and productivity.

The other options refer to different soil layers or components that do not possess the same level of fertility as topsoil. Subsoil, for instance, lies underneath topsoil and contains fewer nutrients. Clay is a type of soil particle known for its small size and can hinder drainage and root growth, while bedrock is solid rock beneath the soil layers and provides no fertility or nutrients for plants.