Components of Topsoil
Topsoil is the outermost layer of the earth's surface. Geologists generally consider the top three feet of the earth's surface to be topsoil. They also know that it takes about 100 years for the earth to produce one inch of topsoil and that our topsoil is disappearing at an alarming rate. Topsoil is composed of four components; the percentage of each varies by region. Does this Spark an idea?
Air
The beneficial bacteria in soil require air in order to live. These bacteria add nitrogen to the soil and aid in the decay of organic matter. Air also adds spaces, or pockets, to the soil that act as small reservoirs for water.
Water
According to the Maine Geological Survey, ground water is the single largest source of fresh water on the planet. Water helps dissolve the minerals in soil, breaking them down so that they are small enough for the roots of plants to absorb them.
Mineral Grains
Minerals are composed of the underlying bedrock. They are the main component of soil and, as they dissolve, provide chemical nutrients for plants. Mineral grains can come from granite, quartz, slate, and other rocks. Mineral grains are what earthworms feast on, further aiding in their decomposition.
Organic Matter
Organic matter is simply the remains of something that was once living. Rich in carbon, organic matter, when it breaks down, produces humus. Humus not only provides nutrients to the soil but acts as a binder, holding soil particles together.
Tags: Components Topsoil, earth surface, Mineral grains
