Answer:
humus
Explanation:
Humus
Humus is the amorphous organic matter in the soil .
It affects the bulk density of the soil and contributes in the retension of the nutrients and moisture of the soil .
It mostly contains organic matter , and is naturally composed from dead and decaying plants and animals .
Humus is a dark color organic matter , and have many nutrients which nourishes and improves the heath of the soil .