It's a mixture of decaying organic substances, such as dead leaves, used to fertilize soil
... 
Botanya mixture of various decaying organic substances, as dead leaves or ... a 
mixture of organic residues such as decomposed vegetation, manure, etc, used 
as a... [DOC] [TLE] Humus - Wikipedia [PAR] In soil science, humus refers to the fraction of soil organic matter that is 
amorphous and without ...