what is soil profile ?explain.
The soil profile is the layers of soil found when we go deeper into the ground. There are three main layers of soil – top soil, subsoil and parent rock.
Topsoil ( A – horizon): Top soil is the upper most layer of the soil which is made up of humus and small particles of rocks. It is dark in colour due to the presence of humus. Plants grow in this soil as humus makes this layer porous and fertile.
Sub soil (B – horizon): It is the layer situated below the topsoil. This layer does not have much humus and thus lighter in colour. Bits of rocks and some nutrients are the main constituents of this layer. Rain water collects in this layer.
Parent rock (C – horizon): Parent rock is the layer below the subsoil which consists of pieces of rocks with cracks and crevices. Below parent rock is the layer of solid rock called bedrock. Water table is formed over it.
A soil horizon is a layer parallel to the soil surface, whose physical characteristics differ from the layers above and beneath. Each soil type has at least one, usually three or four horizons. Horizons are defined in most cases by obvious physical features, chiefly colour and texture. These may be described both in absolute terms (particle size distribution for texture, for instance) and in terms relative to the surrounding material, i.e. ‘coarser’ or ‘sandier’ than the horizons above and below.
Soil Profile refers to the layers of soil; horizon A, B, and C. If you're wondering what horizon A is, here's your answer: horizon A refers to the upper layer of soil, nearest the surface. It is commonly known as topsoil. In the woods or other areas that have not been plowed or tilled, this layer would probably include organic litter, such as fallen leaves and twigs . The litter helps prevent erosion, holds moisture, and decays to form a very rich soil known as humus. Horizon A provides plants with nutrients they need for a great life.
The layer below horizon A, of course, has to be horizon B. Litter is not present in horizon B and therefore there is much less humus. Horizon B does contain some elements from horizon A because of the process of leaching. Leaching resembles what happens in a coffee pot as the water drips through the coffee grounds. Leaching may also bring some minerals from horizon B down to horizon C.
If horizon B is below horizon A, then horizon C must be below horizon B. Horizon C consists mostly of weatherized big rocks. This solid rock, as you discovered in Soil Formation, gave rise to the horizons above it.
Soil profiles look different in different areas of the world. They are affected by climate and other things.
Soil profile refers to the different layers of soil found on earth. A vertical section through the soil gives the soil profile.
- A-horizon – It is the top most soil, which is dark in colour and rich in humus. It is soft, porous, and has the ability to retain water.
- B-horizon – It is the middle next layer of the soil profile.
- C-horizon – It is the third layer made up of small lumps of rocks with cracks.
- Bedrock – It is the lowermost hard layer and difficult to dig with spade.
Hope this helps!
A cross section of the soil through which its different layers are visible is known as soil profile.
The following are the layers of soil from top to bottom:
i) Humus-It consists of undecomposed organic matter.
ii) Top soil- It consists of decomposed organic matter.
iii) Layer consisting of mixture of minerals and decomposed organic matter.
iv) Subsoil- It consists of mineral layers based upon the parent material.
v) Bedrock- It consists of the parent material which is broken down by weathering.