DRIP IRRIGATION
Drip irrigation is by far the most efficient use of our water resources – as long as it’s designed, installed and maintained correctly.
Drip irrigation is a type of micro-irrigation system that has the potential to save water and nutrients by allowing water to drip slowly to the roots of plants, either from above the soil surface or buried below the surface. The goal is to place water directly into the root zone and minimize evaporation.
The demand of water is increasing day by day because of global warming and world population
increase. Available water resources is diminishing. The major consumer of fresh water resources is
agriculture sector. Because of that, increase of the water use efficiency in agriculture has become an
urgency. Drip irrigation method is the most efficient one within the methods which using water in
effective way.
To get expected benefit from drip irrigation depends on projects designed and managed
carefuly by the trained specialists and carefully running the drip irrigation. The system should be
carried out and processed as suggested in the project. The first investing expenses of the drip irrigation
is high and carrying out of drip irrigation requires too much data and skill. Therefore farmers should
be informed about management of drip irrigation systems and they should be made conscious of the
system. So the use of the system will be more effective and productive.
Drip irrigation is sometimes called trickle irrigation and involves dripping water onto the soil at very low rates (2-20 litres/hour) from a system of small diameter plastic pipes fitted with outlets called emitters or drippers. Water is applied close to plants so that only part of the soil in which the roots grow is wetted , unlike surface and sprinkler irrigation, which involves wetting the whole soil profile. With drip irrigation water, applications are more frequent (usually every 1-3 days) than with other methods and this provides a very favourable high moisture level in the soil in which plants can flourish.
Suitable crops
Drip irrigation is most suitable for row crops (vegetables, soft fruit), tree and vine crops where one or more emitters can be provided for each plant. Generally only high value crops are considered because of the high capital costs of installing a drip system.
Suitable slopes
Drip irrigation is adaptable to any farmable slope. Normally the crop would be planted along contour lines and the water supply pipes (laterals) would be laid along the contour also. This is done to minimize changes in emitter discharge as a result of land elevation changes.
Suitable soils
Drip irrigation is suitable for most soils. On clay soils water must be applied slowly to avoid surface water ponding and runoff. On sandy soils higher emitter discharge rates will be needed to ensure adequate lateral wetting of the soil.
Suitable irrigation water
One of the main problems with drip irrigation is blockage of the emitters. All emitters have very small waterways ranging from 0.2-2.0 mm in diameter and these can become blocked if the water is not clean. Thus it is essential for irrigation water to be free of sediments. If this is not so then filtration of the irrigation water will be needed.
Blockage may also occur if the water contains algae, fertilizer deposits and dissolved chemicals which precipitate such as calcium and iron. Filtration may remove some of the materials but the problem may be complex to solve and requires an experienced engineer or consultation with the equipment dealer.
Drip irrigation is particularly suitable for water of poor quality (saline water). Dripping water to individual plants also means that the method can be very efficient in water use. For this reason it is most suitable when water is scarce.
Drip System Layout
Pump unit
Control head
Main and submain lines
Laterals
Emitters or drippers.
Kaynak: http://www.fao.org/3/s8684e/s8684e07.htm
