( A) - Leaching: This is the process where water-soluble inorganic nutrients descend into the soil horizon and get precipitated as unavailable salts. In the diagram, this is usually shown as materials moving downward into the soil.

- Detritus: This refers to the raw organic matter, such as dead leaves or remains of animals, that falls to the ground and serves as the starting material for decomposition.

- Catabolism: This is the process where bacterial and fungal enzymes degrade detritus into simpler inorganic substances.

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