What is topsoil?

Topsoil is defined as the uppermost layer of soil, which plays a crucial role in horticulture and gardening. This layer is where most of a plant's roots are located and is rich in organic matter and nutrients essential for plant growth. The presence of organic materials, such as decomposed leaves and microorganisms, enables topsoil to support a diverse ecosystem that aids in cultivating healthy plants.

The other options do not accurately represent the characteristics of topsoil. The first option suggests that topsoil is dry and hard, which is not true, as healthy topsoil should retain moisture and be loamy for optimal plant growth. The third option, mentioning that topsoil consists mainly of clay, is misleading since topsoil typically contains a mix of sand, silt, and clay, with a predominance of organic matter. Lastly, the fourth option incorrectly describes topsoil as being beneath the subsoil, whereas topsoil is actually the top layer, sitting above the subsoil. Understanding the importance of topsoil enables growers to improve soil health and achieve better cultivation outcomes.