Soil is the Life of Inzalo Community Project
We all know about the basic soil types such as clay, sand and loam, and that certain kinds of soil are better for particular types of plants. According to Lawson it's not as simple as that though. He goes on to say, "It's not the soil itself – it's the soil life that is the most important element."
Microbiology professor, Mary Stromberger agrees that soil does not act alone in plant health and is in fact only partly responsible for plant nutrition and, by association, all life on earth.
What are these mysterious underground forces which are so critical for maintaining a healthy world?
Components of soil
Soil is the 'skin' of the earth and is made up of minerals, water, air and organic matter. It is also home to many millions of animals, insects, bacteria and fungi. Typically, the number of micro-organisms in a cupful of soil outnumber the amount of people on earth!
These organisms, particularly earthworms, 'work' the soil, aerating it, and through processing organic matter, helps the soil become more absorbent and essentially more habitable. Worms also leave a 'slime' line behind as they travel through the soil. This 'slime' is home to a host of soil micro-organisms that continue to live, helping to further breakdown organic material into the base elements, which are then easily accessible to plants.
Importance of soil
Soil has several important functions which serve to sustain life on earth, namely:
- Providing a place for plants to grow
- Serving as a habitat for soil-dwelling organisms
- Emission and absorption of gases for a healthy atmosphere
- Purification and filtration of water
- Recycling of nutrients
Soil consists of 6 layers, called horizons, which offer varying levels of fertility from topsoil down to bedrock. Topsoil is the business end of the deal, able to support life successfully. It takes over 500 years to create just one inch of topsoil, which can easily be washed away by floods unless preventative measures such as swales and drainage are used to prevent erosion.
Over time, outside influences such as temperature, rain and living things act on the soil for better or worse. Without organic matter and organisms to repair any damage caused, soil can become unable to support life and is termed 'dead' or classified as 'dirt'.
Although soil is literally at the bottom of the food chain, all life on earth depends on healthy functioning soil. Maintaining optimum soil conditions takes time and resources. Find out more about the mysteries below the surface of our Inzalo Community Gardening Project.