It is a overhead irrigation, which spray the water through nozzles under pressure over the soil and crop. In sprinkler method of irrigation, water is spread into the air and allowed to fall on the ground surface somewhat resembling rainfall. The spray is developed by flow of water under pressed through small orifices of nozzles. The pressure is usually obtained by pumping. With careful selection of nozzle sizes, the operating pressure and sprinkler spacing the amount of irrigation water required to refill the crop root zone can be applied nearly uniformly at the rate to suit the infiltration rate of the soil, there by obtaining efficient irrigation.
ADAPTABILITY OF SPRINKLER IRRIGATION
Sprinkler irrigation can be used for almost all crops (except rice and jute) and on mot soils however, it is not usually suitable in very fine textured soils ( heavy clay soils), where infiltration rates are less than 4 mm per hour. The method is particularly suitable to sandy soils that have high infiltration rates.
ADVANTAGES AND LIMITATION OF SPRINKLER IRRIGATION
- Suited to complete range of topographies and field dimensions.
- High irrigation efficiency due to uniform distribution of water.
- Accurate and easy measurement of water applied.
- Land leveling is not essential.
- Soluble fertilizer, herbicides and fungicides can be applied in the irrigation water economically and with little extra equipment.
- More land is available for cropping.
- No interfere with the movement of farm machinery.
- Can be used to protect to crop against high temp that reduce the quantity and quantity of heaters.
- Easy to operate, operator may be trained quickly.
- Sprinklers are also used to irrigation high valued plantation crops like, coffee, cardamom and orchards.
- It requires high initial investment.
- Power requirement is usually high since sprinklers operate with more than 0.5 kg/cm2 water pressure.
- Fine textured soils that have low infiltration rate can not be irrigated efficiently in host windy area.
- Loss of water due to evaporation from the area during irrigation.
- The water must be clean and free of sand, debris and large amounts of dissolve salts.
- Wind distorts sprinkler pattern and cause uneven distribution of water.
- Ripening of soft fruit must be protected from the spray.