Glossary · S
Soil horizon
Also known as: soil layer
A soil horizon is a layer of soil that differs from the others in composition, structure, and properties. For tomatoes, the humus layer is of the greatest importance, as this is where most of the root system develops. A well-developed humus layer promotes the storage of water and nutrients. When preparing the planting site, do not remove the humus layer or mix it deeply with the infertile subsoil.