The People’s Choice 2020 Word Of The Year: 2020 Was A $#@#%%$@! Scientists still don’t understand humus completely. Views expressed here do not necessarily reflect those of ScienceDaily, its staff, its contributors, or its partners. Log in. Humus is formed by decomposers such as bacteria, fungi, beetle, ants etc which falls under the saprotrophs. Humus significantly affects the bulk density of soil and contributes to its retention of moisture and nutrients. So to recap the whole compost vs. humus debacle, while humus can be created through the composting process (albeit very, very slowly), compost is not humus until it is decomposed down to dark organic material that can no longer be broken down. The Word Of The Year For 2020 Is …. What’s The Difference Between “Yule” And “Christmas”? Accidentally Created Tidal Marshes Growing Well, Green Energy and Smart Tech: Rare Earth Mineral, Some Grapevines Can Stand Hot, Dry Climate, Diet Modifications -- Including More Wine and Cheese -- May Help Reduce Cognitive Decline, Study Suggests, UV-Emitting LED Lights Found to Kill Coronavirus, Researchers Uncover Blind Spots at the Intersection of AI and Neuroscience, Compressive Fluctuations Heat Ions in Space Plasma. Humus, in itself or by interaction with certain inorganic constituents of the soil, forms a complex colloidal system, the different constituents of which are held together by surface forces; this system is adaptable to changing conditions of reaction, moisture, and action of electrolytes. In soil science, humus denominates the fraction of soil organic matter that is amorphous and without the "cellular cake structure characteristic of plants, micro-organisms or animals". When the material had reached the condition of humus, the bacterial activity decreased to the point where fertility was restored. As humus . 1790–1800;