Soil
Brown is the new gold guys! Brown is the new gold!
If you've been thinking of soil as being :
Plain, homogenous, brown stuff. Which you probably have, as who is taught at school or in daily life that it is anything but? Who has ever been given reason to think that it is anything but brown muck? Who cares?!
Well I would like you to think about your soil completely differently. I want you to look at soil and see this and start caring:
(OK this is a pretty terrible animation, please look past my dyer computer skills! (Free submissions of anything better gratefully received!)) This new vision of our soil is vibrant, bio-diverse - It is filled with many thousands of different life forms, and it is full of action!
Soil is only partly inorganic nutrients, the rest is made up of bacteria, fungi, numerous types of nemotodes, worm and so much more. And the more life you get into your soil, the more the plants will be able to get food from it and protect themselves from pests and diseases. Life in your soil also uses and hold onto huge amounts of carbon. So making your soil as rich and fruitful as possible is not only good for your plants (and you), but also good for the planet. (Google "carbon sequestration" for more).
Structure of soil - the non-organic bits.
The non-organic bits are the components of soil that are not and have never been alive. They are the rocks, sand, silt and clay. These bits hold the minerals and nutrients in their raw form such as potassium, calcium and phosphorus. (A form that plants can't breakdown and use themselves.) The big difference between these components is the particle size. Clay particles are tiny and hold the most nutrients. Silt particles are bigger and sand even bigger.
As clay particles are smaller, they have a greater surface area for bacteria to cling to, - the bacteria then break down and digest the nutrients and minerals, making them available for other organisms and ultimately the plants. Although sand is less nutrient-rich than clay due to its size and make-up, it has an important benefit to the structure of your soil; the large air-spaces created, mean better aeration and water drainage, making it easier for plant roots to grow through the soil and more favorable aerobic conditions for beneficial soil biology.
Structure of soil - the organic, living bits.
Most of the structure of your soil is (or will be when we've helped show you how to develop and maintain it) living, or having been alive. Here is a list of what we want and need to encourage and help to thrive in our lovely soil and some of the jobs they do, starting from the smallest. We saw them all (in a manner of speaking) in the soil animation up there.
Bacteria - break down organic matter and raw nutrients from the inorganic substrate, digesting them to make them bio-available (digestible to other organisms).
Protozoa - process/digest bacteria and release nutrients in plant available forms.
Fungi - Aids decomposition of organic matter, breaks down and stores raw nutrients from inorganic substrate, builds soil structure.
Nematodes - Eat fungi and bacteria (and other nematodes!) and processes nutrients to make them available for other organisms.
Springtails, centipedes, millipedes, mites, insects - AKA "arthropods" and worms - all join in the fun of making the soil a beautiful and hospitable place for everyone to live, by eating and poo-ing and making air spaces and generally spreading bacteria and nutrients all over the place.
So you can see everything here has a very important job in the soil.
After a lot of thinking about how to describe soil, I keep coming back to the idea of getting you to think of a city. Now imagine all the animals of the world coming together to live in that city, some being predators of others, some being helpful, if not implicit in the survival of others. The droppings randomly left on the floor are invitations to a delightful lunch for some creatures and creating the start of a new food chain. (I went through so many scenarios and examples of animals dining on or being helpful to one another to push this point of how so many different life-forms could live together creating a wonderful, rich environment, but I'll spare you the hours of reading and let you do that in your own mind at your leisure. The more numerous and diverse the animals the better!)
Without thinking of the ramifications of humans actually living within a menagerie of wild animals from all continents in one city, think of being able to provide food and suitable living conditions for everyone in that city. This is what we need to do for our menagerie of soil dwelling organisms. And thanks to nature doing its thing successfully for 600 million years, it's easier than you think.