Answer:
A horizon or Topsoil
Explanation:
A horizon or Topsoil is also called the humus layer because it is rich in organic material. This layer consists of small dead animals like bugs, decomposed material and organic matter.
Because of the hummus, the topsoil is soft and porous therefore it allows it to hold enough air and water. This layer is responsible for the germination of seeds and roots of the plants. Also, Many living organisms like earthworms, millipedes, and centipedes, bacteria, and fungi are found in this layer of soil.
