It is an artificial means of watering the crops or an art of supplying water to the crops.

Need for Irrigation : Distribution of water resources are highly varied. While some areas are dry some are wet and humid in such circumstances, we have to arrange water for crops through artificial means for fulfilling their needs. 

Thus, irrigation becomes necessary on account of following reasons.

• Nature of rainfall Due to irregular, uncertain and limited rainfall scarcity of water is caused so, need for irrigation arises. 
• Nature of soil There is greater need of irrigation in sandy soil. 
• Probability of Drought At places of droughts irrigation is essential. 
• Need of Irrigation in dry areas In dry areas, where rainfall is less than 40 to 50 cm per year, the need arises for irrigation. 
• More need of water for special crops like rice, jute, sugar cane etc. 
• More need of water to improve new and high yielding varieties of seeds for higher productivity. 
• Water is essential to develop pastures for cattle and dairy development. 
• Population of India is Multiplying fast, and it needs additional food production. This can be possible only through irrigation.