Question

Percolation is defined as
(a) Amount of water which can pass through the soil
(b) Amount of water which cannot pass through the soil
(c) Amount of pores present in the soil
(d) None of the above

Answer 1

Hint: The term percolation is also used in the field of pharmacology where it refers to the extraction of a soluble portion of the drug by passing it through a suitable liquid. In geology, however, it is related to soil and the pores present in it.

Complete Answer:
Percolation is defined as the amount of water that can pass through the soil. It is dependent on the number and size of the pores present in the soil by which the water can pass through. Thus different soil has different percolation rates due to variation in the pores present in them. This variation in the percolation determines the types of plants that can grow in that particular kind of soil. The type of plants growing i.e. the vegetation determines the kind of animals that will be able to survive in that place. So in a way, percolation determines the kind of ecosystem that will be formed.

Additional information: Let us look at the different types of soil and the percolation rate in them.
Sandy soil: This soil has a very high percolation rate which indicates that it will not be able to hold water and nutrients for a long time. Thus, it will become dry and hot very quickly.
Silty soil: This soil has an intermediate percolation rate thus it holds the water and minerals for long enough so that the plants can absorb it but not too long that plant rotting might occur.
Clay soil: This soil has an extremely slow percolation rate and thus holds water for a very long time which results in the suffocation of the plants and rotting.
So, the correct option is ‘(a) Amount of water which can pass through the soil’.

Note:
- Humus is decomposed organic matter that has a very high percolation rate.
- Plants which have a high tolerance to water scarcity are able to grow in sandy soil.
- Silty soil is the perfect kind of soil for most plants as it shows an intermediate percolation rate.