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This is the first in a series of articles on soil.

What is soil?

Soil is alive!

...with as much life and diversity in it as above it.

Did you know:

a single spade of rich garden soil contains more species of organisms thatn can be found above ground in the entire Amazon rain forest.
plants growing in a 2-acre wheat field can have more than 30,000 miles of roots, greater than the circumference of the Earth.
"Every time you take a step in a mature Oregon forest, your foot is being supported on teh backs of 16,000 invertebrates held up by an average total of 120,000 legs." -- Dr. Andrew Moldenke, Oregon State University (Even in agricultural soils, more than a thousand arthropod legs support your every step!)
One cup of soil may hold as many bacteria as there are people on Earth.
The weight of all the bacteria in one acre of soil can equal the weight of a cow or two.
Earthworms move from 1-100 tons of soil per acre per year.

People see soil in different lights. Earth scientists see soil as mineral or organic material that is formed on the Earth's surface by dynamic, complex processes. To engineers, soil is a material to build on, and they monitor soil moisture and the ability of soil to become compacted and hold weight. Farmers think of soil as the top 15-30 cm of the Earth's surface in which to grow crops. And, when soil, like a weed growing in the middle of a farmer's corn field, is somewhere that it shouldn't be, others think of it as "dirt" which one gets "dirty" from.

Soil is actually an amalgamation of sand, silt, and clay particles, combined with water, air, and many different microorganisms. Soil:

Produces our food and fiber Nearly all of our food and fiber is grown in the soil itself, but soil also provides the nutrients necessary for foods grown in aquatic environments.
	Cleans our water All freshwater travels over or through soil on its way to rivers, lakes and aquifers. Soil soaks up large amounts of rainwater and prevents flooding. This water is then used by plants or channeled to water bodies. Natural soil processes serve to purify and cleanse contaminated water as it soaks through the soil's upper layers.
Regulates our climate Greenhouse gases (carbon dioxide, methane, and nitrous oxides) keep the Earth warm enough to sustain life. They trap some of the sunlight, preventing it from reflecting into space. In excess, however, these gases may increase global temperature (global warming) and affect our weather and climate. Soil reduces greenhouse gases by taking carbon dioxide out of the atmosphere and storing it as soil carbon. Soil microorganisms also change methane and nitrous oxide into less harmful by-products.
	Purifies our waste Soil can recycle nutrients contained in wastes such as sewage sludge, yard waste, food- and fiber-processing sludge, composted garbage, and oil. Some soils can filter and purify wastewater and some are ideal for containing nonhazardous municipal wastes.
Supports our buildings Buildings need stable soil for support. Soil also protects our archeological treasures associated with human habitation.

So you can see that soil is a very important commodity! Without it, our economy would suffer, and we would lose many of the environmental amenities that we have become accustomed to such as clean air and water, diverse wildlife, and beautiful landscapes. Governments cannot buy enough land to provide these amenities to us through parks, forests and similar areas. We, therefore, must rely on the results of individual landowners land use and management decisions to provide us with them.

How is soil formed?

Soil formation and the properties the soil takes on are the result of five factors:

Parent material	This could be bedrock, organic material, an old soil surface, or a deposit from water, wind, glaciers, volcanoes, or material moving down a slope.
Climate	Water, temperature changes, the effects of the atmosphere, and other environmental forces break down the parent material and affect how fast or slow the process goes.
Organisms	Micro-organisms decompose rock and release chemicals for use. They also decompose dead plants and animals into organic matter which enriches the soil. Worms, insects and burrowing animals blend the soil by their activities.
Topography	Soils located at the bottom of a hill will naturally get more water than soils located on a slope. Soils on a slope will also be drier than ones that do not.
Time	It takes thousands of years to form an inch of soil, however, it takes just a few years (or even days or hours when erosion is severe) to destroy it.

These factors interact differently from one place to another and as a result, many types of soils are created.

Soil formation is on-going and, as mentioned above, slow. Because the natural processes, energy exchanges, and biological communities can all be changed drastically by interruptions, it is obvious that soils are fragil and exhaustible. For example, removing plant cover by burning or plowing makes a soil more vulnerable to erosion. These changes will also affect the biological communities in the soil.

Do you know what the symbol below represents?

Visit Pat's Page again in August for the answer!