Geography [2 Mark Question Answer]

There are four main types of Soils found in India:
(i) Alluvial Soil,
(ii) Black Soil,
(iii) Red Soil,
(iv) Laterite Soil.

(i) Indiscriminate cutting down of forests.
(ii) Overgrazing by cattle.
(iii) Faulty methods of cultivation e.g. Jhooming.

Causes of Soil erosion are:
(i) The agents of gradation like wind and water
(ii) Nature of the Soil
(iii) Human factors

Two characteristics or features of the Black Soil which is most suitable for growing cotton and sugarcane in Maharashtra are:
(a) It is fine grained, rich in iron, lime and calcium.
(b) It retains moisture and becomes exceedingly sticky.

Alluvial soils are formed by the sediments brought by the rivers. The rivers deposit very fine silt called ‘alluvium’ in their plains during the course of their journey starting from its source in the mountains and ending till its mouth.
This soil is agriculturally very important because it is a mixture of sand, clay and silt (loamy) which makes it very fertile. It is rich in potash and lime. It is light and porous therefore easily tillable. It is suitable for growing large variety of Rabi and Kharif crops.

(i) Use of fertilizer.
(ii) Crop rotation: Rotation ofxrpps is a system in which farmers grow pulses or leguminous crops after the harvest of a soil exhausting crop. Through this method the soil retains its fertility or gets back the nitrogen.

A rich soil in plant food is the chief requirement of a successful agriculture. It is an essential as a support for plants.
Soil is a very important natural resource of India because agricultural production is basically dependent on the fertility of Soil. Food products like cereals, pulses, fruits and vegetables are obtained indirectly from the Soil.
Two methods:
(i) Contour ploughing. (ii) Afforestation.

Leaching Soil is the process by which soluble substances such as organic basic minerals and mineral salts are washed out of the upper layer of a Soil into a lower layer by percolating rain water, e.g., Laterite Soil.
Found in Karnataka which is south of Tropic of Cancer.

The rate of Soil erosion depends upon:
(i) Character of the slope of land. (ii) The density of vegetation.
(iii) Rainfall—Heavy or Light.

Soil erosioivby water can be of the following sub-types:
(i) Sheet erosion (ii) Rill erosion (iii) Gully erosion
(iv) Stream Bank erosion. (v) Sea-shore erosion. (vi) Slip erosion.

Disadvantages of Laterite Soils are:
(i) They contain high percentage of acidity.
(ii) It is generally coarse in texture and cannot retain moisture.

Red Soil is formed by weathering of crystalline and metamorphic rocks.
Reasons for low productivity:
(i) Deficient in nitrogen, humus. (ii) Porous, friable.

Regur or Black Soil is formed by weathering of volcanic (basalt) rock formed by the Deccan Lava.
Four important features of Regur Soil are:
(i) Fine grained            (ii) Moisture retentive
(iii) Sticky when wet   (iv) Cracks when dry.

Alluvial Soils are of two varieties: Bhangar and Khadar.
‘Bhangar’ is older alluvium. It is found usually higher up in the plains, and occurs at river terraces away from the river. It is found in massive beds, and is characterized by calcareous clays. It is light grey and less fertile. ‘Khadar’ is newer alluvium. It occurs in the lower levels near the river, and is mainly clay loamy. Its new layers are deposited year after year during the season of monsoon floods.

Difference between alluvial soils in the upper and lower courses of the rivers:

Upper course	Lower course
1. It is coarser i.e. particles bigger in size.	It is finer and finest in the lowest section.
2. It is dry, less compact.	It is more moist and more compact.