2. Why do the following occur?

(1) To the west of Sahyadris, laterite soils are formed from basalt rock.

Ans:

i) It rains heavily to the west of Sahyadri’s (Konkan region).

ii) The climate to the west of Sahyadri is humid.

iii) Heavy rainfall and humidity leads to leaching of basalt rock on a large scale giving rise to laterite soils. Thus, to the west of Sahyadri’s, laterite soils are formed from basalt rock.

(2) Humus content in the soil increases.

Ans:

i) The regular use of organic manure, vermicompost or compost help in maintaining the PH balance of the soil.

ii) Microorganisms decompose the dead remain of the plants, animals and other organic materials, this product is called humus, thus by regular use of organic manures, humus content in the soil increases.

(3) Soil formation process is faster in the equatorial climate.

Ans:

i) Weathering of the rock is the first step in the process of soil formation.

ii) High temperature and high rainfall are the main features of the equatorial region. The temperature in the equatorial region is 27⁰ to 30⁰ c and the annual rainfall is 2500mm to 3000mm.

iii) Thus, due to high temperature and high rainfall soil formation is faster in the equatorial climate.

(4) The salinity of the soil increases.

Ans:

i) Irrigation facilities are utilized for producing a greater amount of crops.

ii) Excessive irrigation draws the salts from the soil upward and makes the soil saline and then unproductive.

iii) Thus, due to excessive irrigation the salinity of the soil increases.

(5) Rice is the staple diet of the people from Konkan.

Ans:

i) Hot and humid climate, high rainfall and alluvial soil from Konkan are favourable for the cultivation of rice. Therefore, rice is grown on a large scale.

ii) The local agricultural produce determines the staple diet of the people. Therefore, rice is the staple diet of the people from Konkan.

(6) Soil erosion

Ans:

i) A top layer of soil gets removed by water or wind.

ii) The soil gets eroded due to running water, climate ,steep slopes and velocity of the winds.

iii) Due to these reasons, soil erosion takes place.

(7) Soil degradation. 

Ans:

i) To obtain a higher agricultural yield, chemical fertilizers, insecticides etc. are used.

ii) The excessive spraying of chemicals and chemical fertilizers leads to soil degradation.

iii) Excessive irrigation draws the salts from the soil upward and makes the soil saline.

iv) Excessive use of chemicals is a threat to the microorganisms in the soil and lowers the humus content.

v) The soil quality reduces due to these reasons. Hence it is called the degradation of the soil.

3. Give information on:

(1) Measures of soil conservation.

Ans:

i) Tree plantation – Planting trees can also control the velocity of the wind. This prevents erosion of soil by winds.

ii) Continuous contour trenches – Continuous contour trenches are constructed along the slopes. Construction of such trenches at different heights checks the velocity of water running along the slopes and hence reduces soil erosion.

iii) Water development programme – The government of Maharashtra has implemented this programme under which construction of embankments along slopes are undertaken. Works such as construction of farm bunds, arresting waters of small streams, connecting the streams etc. are carried out on a large scale.

(2) Organic manures

Ans:

i) The vegetal litters, root of plants, remains of animals etc. get decomposed due to water.

ii) Micro-organisms and certain other organisms help decompose the dead remains of organic materials.

iii) This increases the proportion of humus in the soil and the soil becomes fertile.

d) Thus, for conserving soil, the use of organic manures is highly essential.

(3) Place where you will get the information about the suitability of a soil for a particular crop.

Ans:

i) The information about the suitability of a crop can be obtained from soil testing laboratories.

ii) The type of soil, the fertility, the proportion of humus in soil etc. are tested in laboratories at state level and information about it is given to farmers.

(4) Importance of soils for plant growth.

Ans:

i) An important component of the living world on the earth is ‘Plants’ and for production and growth, soil is essential as it provides support to plants.

ii) Vegetation is abundant in the region that have fertile soil e.g. Equatorial region.

iii) In the area where the soil are not fertile, vegetation is scanty e.g. Deserts. 

iv) Where there is shortage of soil, vegetation is not seen. e.g. Polar region.

Q. 4. Complete the following table with reference to soil.