Drip irrigation is a method of watering the plants frequently with the rate of consumption of water by plant, thereby minimizing loss of water due to deep percolation, seepage, runoff and evaporation.
In this method, irrigation is generally (on a small scale) accomplished by supplying water using the small diameter of head soft pipes with devices called drippers or emitters along with the pipe layout. They are spaced according to the spacing of the plant as the pipe is flexible.
The method applies water slowly to keep soil moisturized in root zones within the desire rate of plant use. The application of water can be directly beneath the root zones or above the surface of the soil.
Drip irrigation is also known as trickle irrigation as it lets water runoff in form of drips from the nozzle. It is the latest field of irrigation techniques and well adopted for places where there is a scarcity of water and salt problems in the soil leading to the problem of leaching.
Layout systems of Drip irrigation
In large scale Drip irrigation, the layout involves head, main, sub mains, laterals and drop nozzles. The head consists of the water lifted with a pump to create atmospheric pressure of 2.5 atmospheres in the pipe. This pressure is sufficient to ensure the proper flow of water for the irrigation system. The water sometimes if necessary, are even passed through fertilizer tanks so that directly fertilized irrigated water is supplied to soil.
Moreover, to prevent the suspended particles from going into the drip nozzle and clog them, the fertilized water is preferred to pass over the filter. The main and sub mains are the small-sized pipe arrangements of the system. They are generally flexible PVC pipes are of diameter required accordingly design discharge.
The lateral is very small-sized pipes(usually of diameter 1.25cm) specially designed black PVC pipe directly branched out from mains or sub mains. Laterals length can range up to 50 m long so that one lateral line is laid for each row of crops. The end of the laterals is sealed.
The drip nozzles are called emitters or valves are attached to the laterals at regular intervals of 0.5m to 1m. The lateral is punched in order to make a hole and fit the emitter. The water seeps or oozes out through the emitter at a rate of 2-10 litres per hour.
Sometimes instead of the use of Drip emitters, there is the use of the drip tapes which consists of the flexible pipe along with the permeable members at one end. And such tapes are arranged as lateral on row around crops and water are supplied to it with help of valves.
Advantages of drip irrigation
Each system has its own field and scope of advantages along with some drawbacks. However some advantages of drip irrigation accordingly their suitability and favourable conditions are described below.
- Plants like grapes, sugarcanes, papayas, vegetables are suitable for this irrigation
- This system is very useful for small nurseries, Orchards or gardens.
The new concept of farming in terrace and roof has been recently being adopted popularly. And for such farming, it is difficult to irritate water with normal irrigation techniques like surface or subsurface irrigation techniques.
Moreover, the vase can’t hold much water and seeps and evaporates at a much higher rate than in fields. Thus, drip irrigation techniques are the most suitable and advantageous method of irrigating water in such type of farming.
- Smaller sources of water which are inadequate for other type of irrigation can be used for this type of irrigation with siphon action
- Very advantageous where there is scarcity of water. This method helps in optimization of water as it prevents maximum loss through evaporation and infiltration or deep percolation as compared to other systems of irrigation. Water application efficiency for such irrigation system is greater than 90%
- Widely spaced crops like orchards and vegetables are most favorable for this type of irrigation
- Water along with fertilizers can be directly supplied to root zones of the crop. Thus reduce yhe work and effort needed to done to spread fertilizers.
- Very useful for the sandy loam soil which cannot hold water for long time or say which easily infiltrate water.
Disadvantages of drip irrigation
- Maintenance of laterals and drippers along with flexible pipe is difficult
- Silt free clean water is required to prevent clogging
- Initial cost is too high and require very skill manpower and Trainings
- As the water doesn’t get sufficiently percolate or infiltrate upto depth in soil! The root growth can be hindered to some extent. Thus prefer more for fibrous root plants(like sugarcane) than tap root plants.
I hope this article on “Advantages of drip irrigation” remains helpful for you.
Happy Learning – Civil Concept
Civil Engineer – Rajan Shrestha