Assertion: soil's horizon | /r/HasProperty | darkened by humus
Facets:
Source sentences:
text: A mineral horizon darkened by humus accumulation Base symbols for subsurface horizons E mineral horizon lighter in colour than an A or O horizon and depleted in clay minerals AB or EB transitional horizon more like A or E than B BA or BE transitional horizon more like B than A or E B accumulated clay and humus below the A or E horizon BC or CB transitional horizon from B to C C unconsolidated earth material below