Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter constitutes

Detritus is the raw material for decomposition and includes dead plant remains such as leaves, bark, flowers, and animal remains such as feces. The chemical makeup of detritus and climatic factors influence the rate of decomposition. Decomposition rate is slower if detritus is rich in lignin and chitin in a given climatic state, and faster if detritus is rich in nitrogen and water-soluble compounds like sugars. 

The duff layer is the organic material layer between the A-horizon (or uppermost soil mineral horizon) and the litter layer. It is dominated by organic material derived from the decomposition of plant and animal litter and deposited on either an organic or a mineral surface.

Solonchak is an intrazonal type of extremely salty soils that are often light coloured and lack a distinctive structural form. They grow in poorly drained dry or semiarid environments vegetated mostly by halophytes (salt-tolerant plants).

Humus is a dark-colored amorphous substance that is resistant to microbial action and decomposes slowly. It functions as a nutrition reservoir due to its colloidal nature.