NABARD ( Agriculture & Rural Development) – Irrigation, types of irrigation, sources of irrigation

Irrigation is the artificial application of water to the soil to supplement the rainfall and groundwater contribution to assist the crop production.

Sustainable development and efficient management of water is an increasingly complex challenge in India. Increasing population, growing urbanization, and rapid industrialization combined with the need for raising agricultural production generates competing claims for water. There is a growing perception of a sense of an impending water crisis in the country.

                                                    Objectives /Importance of Irrigation

The importance of irrigation in the world is well stated by N.D. Gulhati of India:
“Irrigation in many countries including India is an age-old art – as old as civilization – but for the whole world it is a modern science – science of survival”.

The broad objectives of irrigation are as follows:
a) To increase crop production on sustainable basis where water is a limitation
•To increase national income/national cash-flow
•To increase labour employment
•To increase standard of living

b) Modification of soil & climatic environment
• For leaching of salts
• For reclamation of sodic soils
• For frost protection

c) To mitigate i.e., lessen the risk of catastrophes caused by drought
• To overcome food shortages
• To protect high value crops/trees

d) To increase population of arid and sparsely populated areas
• For national defence
• For population re-distribution

e) National security i.e., self-sufficiency in food grain production
1) To supply the moisture essential for plant growth.
2) For better utilization of production factors. (Nutrients)
3) To provide crop insurance against short spells of drought.
4) To dilute/washout soluble salts
5) To soften tillage pans
6) Intensive cropping is made possible
7) Timely seedbed preparation and timely sowing.
8) To create favourable microclimate for crop growth.
9) Higher yields as well as stability in production

                                                                Method of irrigation

Depending on soil type slope source of irrigation water, nature of crop methods differs.

1. Surface methods of irrigation
a) Flooding
b) Boarder strip
c) Corrugations
d) Check basin
e) Ridge and furrow
f) Ring or basin

2. Sub- surface methods

3. Sprinkler – system.

4. Drip/trickle irrigation.

5. Quantity of irrigation water depends on rooting depth and water holding capacity of soil.

                                              Types of Irrigation Systems

There are many different types of irrigation systems, depending on how the water is distributed throughout the field. Some common types of irrigation systems include:

Surface irrigation
Water is distributed over and across land by gravity, no mechanical pump involved.

Localized irrigation
Water is distributed under low pressure, through a piped network and applied to each plant.

Drip irrigation
A type of localized irrigation in which drops of water are delivered at or near the root of plants. In this type of irrigation, evaporation and runoff are minimized.

Sprinkler irrigation
Water is distributed by overhead high-pressure sprinklers or guns from a central location in the field or from sprinklers on moving platforms.

Center pivot irrigation
Water is distributed by a system of sprinklers that move on wheeled towers in a circular pattern. This system is common in flat areas of the United States.

Lateral move irrigation
Water is distributed through a series of pipes, each with a wheel and a set of sprinklers, which are rotated either by hand or with a purpose-built mechanism. The sprinklers move a certain distance across the field and then need to have the water hose reconnected for the next distance. This system tends to be less expensive but requires more labor than others.

Sub-irrigation
Water is distributed across land by raising the water table, through a system of pumping stations, canals, gates, and ditches. This type of irrigation is most effective in areas with high water tables.

Manual irrigation
Water is distributed across land through manual labor and watering cans. This system is very labor intensive

sources of irrigation

The main sources of irrigation in India are:

1. Canals
2. Wells (and tubewells)
3. Tanks