Question

Please answer the question​

Answer 1

Match items in Column A with items in Column B :

Column A :

(1) A - Horizon

(2) B - Horizon

(3) C - Horizon

(4) R - Horizon

(5) Alluvial Soil

Column B :

(a) Khadar

(b) Lumps of rocks

(c) Humus

(d) Subsoil

(e) Parent rock

(1) - (c)

(2) - (d)

(3) - (b)

(4) - (e)

(5) - (a)

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• (1) - (c)

The uppermost layer or Horizon A is generally dark in colour and is rich in humus and minerals. This layer is generally soft, porous and can retain more water.

• (2) - (d)

The Subsoil has a lesser amount of humus but more of minerals. This soil is present in B - Horizon.

• (3) - (b)

The third layer is the C- Horizon which is made up of small lumps of rocks. with cracks and crevices.

• (4) - (e)

The fourth layer which is bedrock or Horizon R contains parent rocks. It is hard and difficult to dig with a spade.

• (5) - (a)

Alluvial soil also known as Khadar contains sand, slit and clays. This soil is suitable for Sugarcane, wheat and rice.

Answer 2

Matching:-

1.A-Horizon - (c) Humus

2.B-Horizon - (d)subsoil

3.C-Horizon - (b) Lumps of rocks

4.R-Horizon - (e) Parent rock

5.Alluvial soil - (a)Khadar

Key points:-

✦Soil horizon:-  A distinct layer of soil which is parallel to the surface and possess different physical, chemical and biological characteristics than that of the layers above and beneath.

✦Types of soil horizons:

• O-Horizon
• A - Horizon
• E - Horizon
• B - Horizon
• C - Horizon
• R - Horizon

✦A - horizon :-

• Referred as "topsoil"
• Top layer of the  soil horizons
• Contains humus.

✦Humus: The dark, organic material present on top of the soil which is made up of dead and decaying matter, dried leaves,microbes and other nutrients,etc.

✦B - Horizon:-

• Referred as subsoil
• Transition  zone between the ‘horizon A’ and ‘horizon C’.
• Contains matter derived from below as well  as from above.
• The mineral matter is noticeably  weathered.

✦C-Horizon:-

• The layer of soil just below the sub-soil.
• Lacks in humus
• Made up of small lumps of rocks with cracks.

✦R - Horizon:-

• Not soil , located under C-horizon
• Bedrock;A mass of rock such as granite, quartzite, etc,that forms the parent material for some soils.

✦Alluvial soil:-

• They vary from sandy  loam to clay.
• Rich in potash  but poor in phosphorous.
• Khadar is the new type of alluvium soil which is  deposited by floods annually, which enriches  the soil by depositing fine silts.

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