Soil Part 1: Grow your cake and eat it too
Updated: Aug 3, 2020
Photo by: Tim Babb as featured on Threadless
Soils are such versatile and complex organisms filled with a diversity of structures and organisms both living and dead. Soils can be difficult to understand, especially when you have not delved deeply into the field of soil science.
I truly believe that soils are one of the most valuable resources we have on this planet, and that once you take a little bit of time to learn about them you will see first hand how they have an impact on your life everyday. I am so passionate about sharing this information with you so that you can feel more equipped to interact with others on the topic and fully understand the value of what lies below your feet.
Let's start off by understanding how soils are classified.
The USDA NRCS (Natural Resource Conservation Service) created twelve soil orders to categorized soils from around the world.
It is easy to think that soils are more of a horizontal observation rather than vertical, but I assure you that once you start digging and examining the depth of soils you will have a whole new world open up to you!
Soil orders are created by observing the climate, organisms present, relief, parent material, and time it has taken to form (also known as CLORPT is a lovely acronym that we use in the field).
These soils are evaluated by digging a soil pit to examine the horizontal layers and all of their distinctive features.
Below is a very simple soil profile for you to start your journey into soil classification.
Every soil profile will have horizontal soil horizons. These may include any of the master horizons O, A, B, C, R and even and E depending upon its location. There can also be a combination of these (AB, BC ) or multiples of one horizon (B1, B2).
O- Organic materials: layer where living things accumulate and
start to decay
A- Topsoil or the area where you can find high concentrations of
fully decomposed organic matter, aka humus.
B- Often known as the Subsoil or zone of accumulation. This is where the highest concentration of clays can be found.
C- This is the parent material and is greatly responsible for the unique characteristics and development of that specific soil.
Soil profiles may also have an E horizon or leaching zone where all of the nutrients have been translocated away. It is a very pale or even white layer that is indicative of specific soil orders (such as Spodosols found at the Oregon Coast). R (rock) horizons are the foundation to all soils. They are the purely geological component of the soil profile.
These horizons can be differentiated by observing specific features (clay, organic materials, mineral component, color, and texture etc.). In another post I will be explaining how to texture soil, and some of the other factors used for soil classification.
Why is this important?
Once soils have been placed into an order we can see the similarities between soils around the globe. This can explain specific soils and their functions regardless of location. You may live on one side of the planet and choose to move across the world to a similar bioregion and discover that your soils fall within the same categories, which means your plants from back home may also thrive in your new habitat!
Let us know if there is anything else you are curious about exploring! We would love to know what you think and if you have explored your soil.