Humus is a soil type described by Tom Stevenson (2011) as ‘organic material that contains bacteria and other micro-organisms that are capable of converting complex chemicals into simple plant foods. Humus makes soil fertile; without it, soil is nothing more than finely ground rock.’

Erhard Hennig says ‘Humus forms as a result of the complicated interplay between inorganic conversions and organic creatures such as microbes, nematodes, and earthworms. Humus formation is carried out in two steps. First, the organic substances and minerals in the soil disintegrate. Next, totally new combinations of these broken-down products develop. This leads to the initial stages of humus. Humus formation is a biological process. Only 4-12 inches (10-30 centimeters) of humus-containing soil are available in the Earth’s upper crust. This thin layer of earth is all that exists to provide nutrition to all human life. The destiny of mankind depends on these 12 inches!’

Bibliography

Tom Stevenson (2011) The Sotheby’s Wine Encyclopedia 5th Edition by Tom Stevenson (Dorling Kindersley, 2011), p.17-19.

Erhard Hennig, ‘Humus: What is it and how is it formed? Eco Farming Daily (retrieved 11 Jan 2021).