Question

what is soil?
1) formation of soil briefly define?
2) soil profile?
3) Composition of soil?
4) Types of soils?
5) Soil erosion.
6) Causes of soil erosion?
7) Effects of soil erosion?
8) prevention of soil Erosion
All points describe briefly and by points wise.

Answer 1

the loose unconsolidated particles of rocks found on the earth surface is called soil.
1)soil is formed by the disintegration and decomposition of parent rock
2)the vertical section of the soil that depicts all the layers of the soil is called soil profile.
3)soil is composed of organic , inorganic components,air,water,minerals.
4)types-
alluvial soil
black soil,
red soil
laterite soil
mountain soil,
desert soil
5)the removal of the top soil which deplete the fertility of the soil is called soil erosion.
6)soil erosion is caused due to-
a)faulty method of farming like shifting agriculture,
b)overgrazing of animals.
c)agents of erosion such as wind,running water and ice
d)sand dunes.
e)human activity like minning,quarrying,etc.
7)soil erosion decreases the fertility of the soil which in turn decreases the production as well as quality of production.

Answer 2

What is Soil ?
Soil is the upper weathered mineral and humus containing past of earth's crust which support plant life and contains several living organisms and their remains. 


Formation of soil :
The formation of soil depends on the parent rock material, the climate and topography of the area, the organisms found in the soil and the time over which the soil has been developing. Over long period of time, thousands and millions of years the rock near the surface of the Earth are broken down by different physical, chemical and some biological processes. The end product of this breaking down is the fine particles of soil.

Factor or processes for soil formation :
 
 (i). The sun : The sun heats up rocks during the day such that they expand. At night, the rocks cool down and contract. The unequal expansion and contraction in various parts of the rock results in the formation of cracks and ultimately rocks split up into smaller pieces.

(ii). Water : Water helps in the formation of soil in two ways :    Firstly, water could get into the cracks in the rocks formed because of uneven heating by the Sun. If this water freezes, it will widen the cracks.  
 Secondly, fast flowing water carries big and small particles of rock downstream, leads to breakdown of rock particles into smaller, finer particles through their abrassive effect.


(iii). Wind : Strong winds also erode rocks down. They also carry sand from one region to the other like the water does.

(iv). Living organisms : Living organisms also influence the formation of soil. While lichens grow on surface of rocks, they release some substance that cause the rock surface to powder down and form a thin layer of soil. Likewise, small plants like moss and roots of big trees also split the rocks.


Composition of soil :
Composition of soil means what makes up the soil.
 
 Soil is a mixture of :-
  --- Air
  --- Water
  --- Rock particles/ minerals
  --- humus


Types of Soil :
There are many types of soil. Some are given as follow :
 1. Sand
 2. Silt
 3. Clay
 4. Loam
 5. Gravel
 6. Peaty
 7. Chalky


Soil Erosion :
The process of carrying away the upper fertile layer of soil by air and wind is known as Soil Erosion.

Causes of Soil Erosion:
Soil Erosion is caused by following processes.
  --- Water flowing downhill
  --- Wind
  --- Deforestation
  --- Overcropping
  --- Overgrazing 
  --- Soil exhaustion 


Effect of Soil Erosion :
Effect of soil erosion are as follow :
 --- The loss of soil
 --- Breakdown of the soil structure
 --- A decline in organic matter
 --- Sedimentation Downstream
 --- Risk of flooding.


Prevention of Soil Erosion:
Prevention of Soil Erosion are as follow.

1. To grow maximum crops
2. To prevent excessive grazing
3. To prevent felling down the tree as well as planting new tree.
4. To keep the fertility of the soil.