How Is Topsoil Formed?

Importance of Topsoil

A world without topsoil is a world without plants and food production. Topsoil is a vital resource and crucial to survival for most living beings. In 1937, Roosevelt said, "The nation that destroys its soil destroys itself." Topsoil permits all types of living things to live and thrive. However, it does call for particular elements to be present in order to form. It forms naturally all over the earth, unless no disturbances or improper human actions occur.

Vital Ingredients

Specific ingredients are required for topsoil formation. If one of the elements is absent or altered, poor topsoil will be present and function ineffectively. Healthy topsoil will preserve enough moisture for the required living organism activity and root growth. Six ingredients are critical to the formation of topsoil. These are minerals, air, water, animals and plants living in the soil (and their by-products), animals and plants living on the soil (and their by-products) plus customary and irregular disturbances of the topsoil.

Formation of Topsoil

Weather and wear--extreme freezes and thaws, wet and dry periods plus additional natural occurrences--chip off small bits of minerals from different types of rocks. These particles are known as "parent material." The dimension and chemical makeup of the parent material establishes the characteristics of the topsoil, such as pH level and whether it is silt, clay or sandy soil. Soil is formed when it is living (that is, consisting of plants and animals). These tiny living organisms range from those much smaller than you can see with your eyes (bacteria, fungi and others) to large ones like insects, worms, moles and even gophers. Small quantities of topsoil can contain thousands of microorganisms that live and survive together. For soil to be living it must be covered, and this takes place naturally when plants' roots spread throughout the soil and hold it in place. Suitable disturbances, whether natural or manmade, form stronger plants. The strong plants will hold the topsoil in place allowing it to form properly. The process required to form topsoil can take various periods of time, depending on the conditions and elements present at the location. It does form quicker than the weathering process that creates the parent material, which can require thousands of years. Humans can easily disturb or destroy topsoil, but we can create and improve topsoil as well.

Keywords: topsoil formation, soil components, plants and animals

About this Author

Diane Dilov-Schultheis has been writing professionally since 2000. She is a food and travel writer who also specializes in gaming, satellites, RV repair, gardening, finances and electronics. She is a member of the Society of Professional Journalists and has been published online at the Travel Channel and Intel.