Mumbai University > Civil Engineering > Sem 7 > Irrigation Engineering

Marks: 7M

Year: Dec 2015

1. Drip irrigation is also known as trickle irrigation, water is applied in the form of drops directly near the base of the plant.
2. Water is conveyed through a system of flexible pipe lines, operating at low pressure, and is applied to the plants through drip nozzles.
3. This technique is also known as ‘feeding bottle’ techniques where by the soil is maintained in the most congential form by keeping the soil-water-air proportions in the optimum range.
4. Drip irrigation limits the water supplied for consumptive use of the plant by maintaining minimum soil moisture, equal to the field capacity, thereby maximising the saving.
5. The system permits the fine control on the application of moisture and nutrients at stated frequencies

Favourable conditions to use drip irrigation:

1. Crops:- Drip irrigation is most Favorable for row crops (vegetables, soft fruit), tree and vine crops where one or more emitters can be provided for each plant.
2. 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.
3. Soils:- Drip irrigation is Favorable 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.
4. 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 clean and free of sediments.

Favourable conditions to use sprinkler irrigation:

1. Crop:- Sprinkler irrigation is suited for most row, field and tree crops and water can be sprayed over or under the crop canopy.
2. Slopes:- Sprinkler irrigation is adaptable to any farmable slope, whether uniform or undulating. The lateral pipes supplying water to the sprinklers should always be laid out along the land contour whenever possible.
3. Soils:- Sprinklers are best suited to sandy soils with high infiltration rates although they are adaptable to most soils.
4. Irrigation water:-. A good clean supply of water, free of suspended sediments, is required to avoid problems of sprinkler nozzle blockage and spoiling the crop by coating it with sediment.