Question

Define irrigation. What is the necessity of irrigation?

Answer 1

giving the water to the crop in a particular interval of a time is known as irrigation...

Necessity of irrigation are...
1. due to irrigation the crop are more healthier.
2. without irrigation crop doesn't grow.

Answer 2

HEY MATE HERE IS YOUR ANSWER ♥♥♥

Irrigation may be defined as the process of artificially supplying water to soil for raising crops.Water is necessary for plant growth and maturity. Irrigation, the artificial means of supplying water, becomes important for plant growth in the following cases.

If rainfall is less than the demand of plants, irrigation is necessary to fulfill the water requirement of plants.

The difference in water holding capacity of the soil plays important role in the Necessity of Irrigation supply. For example, sandy soil requires frequent irrigation than clay soil.

If rainfall is sufficient but spatial distribution is not as per requirement, irrigation becomes necessary.

If rainfall is sufficient, spatial distribution is also good but temporal distribution is not as per requirement, irrigation water is necessary for plants.

An advanced scientific development like High Yielding Varieties Seeds (HYV) demands irrigation. Actually, irrigation is the most important input for HYV. 

HOPE THIS HELPS YOU ♥♥♥