explain different types of soil layers (give definition for each)
Answers
Answer:
Explanation:
Soil consists of the following horizons:
1. Horizon A or Topsoil
It is also called the humus layer, which is rich in organic material. This layer consists of decomposed material and organic matter. This is the reason, the topsoil has a dark brown color. The hummus makes the topsoil soft, porous to hold enough air and water. In this layer, the seeds germinate and roots of the plants grow. Many living organisms like earthworms, millipedes, and centipedes, bacteria, and fungi are found in this layer of soil.
2. Horizon B or Subsoil
Just below the topsoil lies another layer called subsoil or horizon-B. It is comparatively harder and compact than topsoil. It is lighter in color than the topsoil because there is less humus in this layer. This layer is less organic but is rich in minerals brought down from the topsoil. It contains metal salts, especially iron oxide in a large proportion. Farmers often mix horizon-A and horizon-B when ploughing their fields.
3. Bedrock or Horizon C
Bedrock is also known as parent rock and lies just below the subsoil. It contains no organic matter and made up of stones and rocks, so it is very hard. This layer represents a transition zone between the earth’s bedrock and horizon A and B.
Answer:
Top soil:
Explanation:
Topsoil is the upper, outermost layer of soil, usually the top 5–10 inches (13–25 cm). It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs. Topsoil is composed of mineral particles, organic matter, water, and air.
Subsoil:
Subsoil, Layer (stratum) of earth immediately below the surface soil, consisting predominantly of minerals and leached materials such as iron and aluminum compounds. ... Below the subsoil is a layer of partially disintegrated rock.
Weathered rock: The rocks formed after weathering process are know as weathered rocks. Weathering of rocks describes the process of weakening and breaking down of rocks and minerals. This can happen via both nonliving and living factors, such as temperature changes, plants and animals, acids, salts and water, whether solid or liquid. Weathering of rocks takes place over a period of time.
Parent rock:Parent rock, also referred to as substratum, refers to the original rock from which something else was formed. It is mainly used in the context of soil formation where the parent rock normally has a large influence on the nature of the resulting soil.
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