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What is Soil Fertility?

What is Soil Fertility?

When we discuss soil fertility, we are referring to a soil’s ability to support life or allow plant life to grow and thrive. Healthy soil is composed of a combination of the mineral rocks, sand, silt and clay. It is also composed of decaying and decayed organic matter or humus. Humus is integral to soil health due to its ability to provide soil with structure, allow it to hold water and support microbial life. 

What are the benefits of minerals for plants?

To put it simply, plants need minerals to survive and grow. Minerals are necessary for everything from the creation of proteins to photosynthesis. In a natural ecosystem, rock minerals in the soil become soluble and are taken up by a growing plant. When a plant returns to the earth to be decomposed at the end of its life cycle, minerals are returned to the soil. So, in a thriving ecosystem, there is a constant cycle, a harmonious balance, of nutrients being taken up and returned to the soil.

Problems arise, however, when there is a disruption in this balanced system and soil starts to erode and lose nutrients and minerals. Natural factors such as wind and water can contribute to soil erosion either by blowing or washing soil away. Monocrops or monocultures can also deplete a soil of minerals. If a crop requires an abundance of a certain mineral to thrive, over time, without crop rotation, the soil will become deficient in the necessary mineral.

Leaving soil bare also has devastating consequences for soil fertility and planetary health. Without vegetative coverage, bare soil soon becomes barren soil. Left uncovered, not only will soil easily erode, but it will also lose large amounts of carbon to the atmosphere. During photosynthesis plants take carbon from the atmosphere and utilize it for growth; any carbon that is not utilized for above-ground growth is directed towards plant root systems and also stored in the soil. So, vegetation and cropped-fields are natural carbon storage facilities. If a field is left barren, however, large amounts of carbon in the soil will oxidize and be released into the atmosphere.

Why is this oxidized carbon a problem? Well, when sunlight passes through the atmosphere and warms the surface of the earth, most of the heat is supposed to radiate back into space. When there is too much carbon in the atmosphere, it prevents the heat from radiating back into space and, thus, causes the heat to remain trapped in our atmosphere. This trapped heat and gradual warming of the planet has devastating climatic consequences; imagine how you would feel and behave if your body temperature were to rise a few degrees? Too much carbon and other “greenhouse” gases in the atmosphere can induce a catastrophic earthly fever.

But again, there is a remedy for this dangerous process! By focusing on soil health, we can sequester carbon to the safety of rich and fertile soil; with proper soil management, we can rehabilitate the soil to hold carbon and heal the planet.

What can be done about nutrient depletion in soil?

Some very simple solutions to foster rich and fertile soil include:

  1. Focus on humus; compost and contribute as much organic matter to the soil as possible.
  2. Add rock dust or mineral powder to the soil. A humus-rich soil with a balanced mineral profile will not only be more resilient to the stresses that contribute to erosion, but will also provide an environment that is optimal for plant health and growth.

And remember, the minerals that a plant assimilates from the soil are the same minerals we, as human beings, require to live and thrive. Supplement the soil for super foods and superior health!

References:

Davies, B., Eagle, D., and Finney, B. (2001). Resource management: soil. Farming Press: United Kingdom.

Gardiner, D.T., and Miller, R.W. (2004). Soils in our environment, 10th Ed. Pearson Education, Inc., New Jersey.

National Aeronautics and Space Administration. Global climate change: vital signs of the planet.

Nardi, J.B. (2003). The world beneath our feet. Oxford University Press, New York.