2.6.1 Soil health in a nutshell

What is the essence of a healthy soil? It’s alive! And it’s alive with aerobic (oxygen-dependent) microorganisms in mutually dependent relationships with plants. So, although we included the mineral component, the organic matter component and the aerobic microorganism component in the composition of healthy soil, plants are a really important part of soil health too.

Soil health is not purely a localised phenomenon, it has impacts well beyond itself, on our bodies’ functioning well, on climate stability, on plants’ ability to fend off pests and diseases, and more.

Healthy soils present potential for so many benefits, and solutions to a multitude of problems.

The main take home points from this module include:

  1. Topsoil is (or at least should be) composed of mineral, organic matter and aerobic (oxygen-dependent) microorganisms.
  2. Plants’ ability to make food through photosynthesis makes them producers while almost all other living beings on our planet are consumers and fully dependent on plants as a food source (whether directly or indirectly through eating other consumers).
  3. Photosynthesis is the process whereby water and carbon dioxide are converted to sugars and oxygen with the help of sunlight
  4. Plants interact with soil microorganisms through a trade-like system, where plants provide sugars which they produce through photosynthesis, and microorganisms provide amongst other things, other nutrients to the plants. Soil microorganisms are the key to the locked cabinet of nutrients. They make nutrients in the soil accessible in a plant-available form. 
  5. Good soil structure is essential for ensuring spaces for air and water, while protecting the soil from erosion and compaction. Soil microorganisms are key players in the creation of soil structure. .
  6. In a healthy soil, plants and soil microorganisms contribute significantly to carbon sequestration, bringing carbon down from the atmosphere for storage in a stable form known as humus, in the soil. 

In this module we have explored where we want to get to and the potential of healthy soil. In the next module, we’ll explore some of the factors which have contributed to soil degradation.