Organic Substances - Abiotic Components

These include carbohydrates, proteins, lipids and their derivatives which are derived from the waste products of plants and animals or are the remains of dead plants and animals. Organic fragments of different sizes and composition formed as a result of decomposition of organic residues are collectively called organic detritus. Decomposing organic matter releases nutrients along with the formation of a dark, amorphous, colloidal substance called humus which is important for the fertility of soil. New humus is added as old humus gets converted into mineral elements.