Horizons Of Soil Profile and Importance

Hello welcome to this blog. Topic: Soil Profile, horizons of soil profile and importance in agriculture From A to D

Table Of Contents

1. Definition of soil profile
2. Horizons of soil profile
3. Importance of soil profile
4. Revision Questions.

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SOIL PROFILE

Definition: Soil profile is defined as the vertical section of the soil, showing series of horizontal layers of different types of soil. This horizontal layers are called horizons.

A Soil profile is an area of the humid tropics such as the forest zones may have about four fairly distinct horizons. The first thing that is noticed in a soil profile is soil color. The horizons show different colors, e.g, the top soil may be dark, followed by Brown below. After the color the next feature which can be noticed is the texture or particle sizes which increase from the top to the bottom. This two characteristics enable the different horizons to be identified.

HORIZONS OF SOIL PROFILE

The four major horizons of soil profile are:

1. The A – Horizon: Also called the top soil, represents the surface layer of soil profile. This horizon contains more organic matter than other Horizons. The A – Horizon, the top soil, is the most weathered and leached of all the soil horizons. Most food crops, especially shallow rooted crops derive their nutrients from this top soil, e.g, vegetables, legumes, etc.

2. B – Horizon: The B – Horizon, also called the sub-soil, is the next horizon immediately after the top soil. It is rich in minerals which are carried or leached down by percolation water. The B – horizon is suitable for the cultivation of deep rooted crops like Cocoa, rubber, orange, oil palm, etc.

3. C – Horizon: The C – horizon also called parent materials, represent the types of material from which top soil and sub-soil are derived. It is the parents materials which are small fragments of rocks that are unweathered and found at the bottom of the soil profile.

4. D – Horizon: The D – Horizon is also called the bedrock. It represents the unweathered Rock materials. This Horizon is found at the bottom of the profile and they are usually of large soil particles.

Importance of Soil Profile

The suitability of a soil for agriculture is determined by looking at the soil profile.

The importance of soil profile includes:

1. Level of soil fertility: SOIL profile determines the level of soil fertility. A thick top soil represent high level of soil fertility.
2. To know the type of crop to grow: It helps the Farmer to know the type of crop to grow. For example, shallow rooted crops like cowpea, groundnut, etc are grown in the top soil, while deep rooted crops are grown where the sub-Soil thick.
3. Penetration of roots: A loosely packed sub-Soil allows for easy penetration of roots of crops.
4. Level of drainage and aeration: A loosely packed sub-Soil allows for easy drainage and aeration.
5. Easy percolation: A loosely packed sub-Soil also ensures easy percolation of water, thereby preventing the occurrence of Erosion.

Revision Questions

1. Define soil profile
2. List and explain types of horizons of soil profile
3. Write short notes on soil profile