In the peer-reviewed Soil Biology Primer (Soil and Water Conservation Society, 2000), Dr. Elaine Ingham - who founded Soil Foodweb School...

A microscope assessment of your soil biology is essential because the amounts and composition of those microorganisms in your soil...

"Humus" is a word used in many gardening articles and books - even recent textbooks - about soil. You may find bags of "humus" for sale...