Dark organic material in soils (5)
I believe the answer is:
humus
(Other definitions for humus that I've seen before include "Organic stuff" , "Decomposed vegetation" , "Organic "fertiliser"" , "decomposing organic matter" , "Compost" .)
I believe the answer is:
humus
(Other definitions for humus that I've seen before include "Organic stuff" , "Decomposed vegetation" , "Organic "fertiliser"" , "decomposing organic matter" , "Compost" .)