top of page
  • Writer's pictureStronger Roots

Soil Horizons (O and A)

🔷A Soil Profile is a map of the distinct layers or HORIZONS in the ground of different materials… (organic matter, clay, humus, etc.)

🔷 “Soil scientists have attached a letter or combination of letters to each horizon that appears in any typical soil profile. For the gardener, the top horizons, the O and A, are really the only ones that count”

-Teaming with Microbes

Oi = FIBRIC - contains organic material that can still be specifically identified.

Oe = HUMIC/HEMIC - Has experienced more decay, and while materials are identifiable like let’s say plant matter, you cannot tell which specific plants are involved.

Oa = SAPRIC - Is where the organic material has decomposed so much that you cannot tell its origin; it could be from plants or from animal matter.

A = (Topsoil) Located directly below the O layer; This layer is made up of minerals and decomposed organic matter and very dark in color. This is the layer that many plants roots grow in!

10 views0 comments

Recent Posts

See All
bottom of page