what is irrigation describe its methods

Irrigation:

Irrigation is the artificial application of water to plants for crop production.

Method of irrigation :

1. Surface irrigation.
2. Sub-surface irrigation.
3. Aerial irrigation /overhead.

Surface Irrigation:  It is a common method of irrigation. India 90% of the total irrigation of India is applied by surface irrigation.

1. Flood method:  It is an ancient and popular method It does not irrigate fields equally. It is a nonscientific method and has the lowest irrigation efficiency (25-35%). Ex. Irrigation of Paddy field
2. Stripe method (Border method): The field is divided into strips. These strips are built on a 0.5% slope. The length of the strip in sandy loam soil is 60-90 meters and 150-200 meters. The width of the stripe is 3-6 meters depending upon the type of Irrigation of Wheat, Barley, Gram, and Mustard.
3. Check Basin Method (Bed method): The field is plain and the source of irrigation is small, check basin method is used. The field is divided into small rectangles and attached to an irrigation channel. Ex.-Irrigation of Vegetables
4. Furrow Method: It is useful for crops sown on ridges. Irrigation water is applied in furrows. Ex. Potato, Onion, Sugar Beet, Sugarcane, Banana.

The water flows directly to the root zone of the crops, so the irrigation efficiency of the furrow method is more than the previous three methods. It is again divided into two parts based on slope.

a) Flat furrow Method: -This method is used in an area that has 0.3% or more slope. The length of the furrow should be 20-40 meters in light soil and 200-300 meters in clay soils. The depth of furrow is 30-60 cm in various crops. It is also called the Deep furrow method

b) Contour Furrow Method:– It is used when the slope of the land is 2-5%. Furrows are built across the slope. It is used in hilly areas

5. Ring or Basin Method: The ring method is commonly used for horticultural crops. Basins are constructed around the fruit trees and connected with the irrigation channel. Irrigation water loss can be minimized by this method, so it has good irrigation efficiency. E.g. Irrigation of Horticultural crops and Fruits.

Importance of irrigation for plants:-

1. Various plant parts consist of 80-90% water.

2. Protoplasm consists of 90% water and cell division does not take place without water.

3. Germination does not take place in the absence of water.

4. Plant uptakes nutrients in liquid form, so moisture is essential in the soil.

5. Water regulates the temperature in plant crops and can be prevented from frost and heat waves by the application of irrigation.

6. To produce 1kg of dry matter, the plant requires 400-500 liters of water Paddy requires the maximum amount of water to produce per unit kg of dry matter. It is about 5000 liter of water/kg dry matter