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ECO-FRIENDLY TECHNOLOGIES
AGRICULTURAL TECHNOLOGIES
IRRIGATION WATER CONSERVATION
As
irrigation accounts for 92% of water consumption, therefore proper attention
is required to conserve this water. To meet this requirement we have
following two methods:
-
Sprinkler System
-
Drip
Irrigation
-
On
Field Practices
Sprinkler System:
Ground
water recharge may in increased by soil conservation measures and artificial
recharge procedures. The amount of water infiltrated into the soil varies
with the condition of soil surface and the moisture content of the soil at
the time of rainfall. The total amount of water infiltered depends on the
infiltration opportunity time, which depends mainly on the slope of the land
and the field structures like contour bunds, terraces and other structures,
which tend to hold the runoff water over long periods on the land surface.
Adaptability
of Sprinkler System:
-
Sprinkler irrigation can be used for almost all crops (except rice and
jute) and on most soils. It is however, not usually suitable in very
fine textured soils (heavy clay soils) where the infilteration rates
are less than about 4mm per hour.
-
The
flexibility of the sprinkler equipment and its efficient control of
water application make this method adaptable to most topographic
conditions without extensive land preparation.
-
The
amount of water can be controlled to meet crop needs, and light
application can be made efficiently on seedling and young plants.
-
Soluble
fertilizers, herbicides and fungicides can be applied in irrigation
water economically with little extra equipment.
-
Sprinkler irrigation is becoming increasingly popular in India in
regions of water scarcity where available water is insufficient to
irrigate the command area by surface irrigation.
-
Sprinkler are also being increasingly used for irrigating high valued
plantation crops like tea, coffee, cardamom and orchards.
Drip Irrigation
-
Drip or
trickle irrigation is one of the latest methods of irrigation which is
becoming increasingly popular in areas with water scarcity and salt
problems. It is a method of watering plants frequently and with a volume of
water approaching the consumptive use of plants, thereby minimizing such
conventional losses as deep percolation, runoff and soil water evaporation.
In this method irrigation is accomplished by using small diameter plastic
lateral lines with devices called "emitters" or "drippers" at selected
spacing to deliver water to the soil surface near the base of the plants.
The system applies water slowly to keep the soil moisture within the desired
range for plant growth.
-
In
comparison to surface irrigation methods, drip irrigation can achieve 90
percent or more application efficiency.
Adaptability of Drip Irrigation System
-
Crops
like grapes, sugarcane, papayas, banana, guava and most other types of
fruit trees and vegetables have been found to respond well to drip
irrigation.
-
There is
considerable saving in water by adopting this method since the water
could be applied almost precisely to the root zone and there is no
need to wet the entire area between tree crops.
-
Amount
of water supplied can be varied depending on the stage of growth of
the plant.
-
The
method reduces salt concentration in the root zone when irrigated with
poor quality ground water.
-
Like the
sprinkler method, drip irrigation permits the application of
fertilizers through the system.
-
Moreover, the drip method of irrigation operates on much lower line
pressure, thus providing a saving in energy requirement.
On field Practices
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Agronomic practices like off-season tillage (prior to pre-monsoon
showers) conserve soil moisture. Moisture penetration to a depth of 90
cm is achieved if the land is ploughed to a depth of 30 cm. Other
practices like early sowing of seeds, moderate use of fertilisers,
weeding, pest and disease control and timely harvesting increase the
yield inspite of limited moisture in the soil.
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Mulching the soil with organic residue conserves soil moistures.
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Terrace cultivation of hilly slopes prevents water run off.
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Contour ploughing and planting of grasses and trees check run-off
water and increase the soil's capacity to retain moisture.
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Green manuring (incorporation of fresh green leaves into the soil)
and crop-rotation (cultivating different crops in rotation depending
upon the soil and climate, e.g. cereals followed by legumes) conserve
soil moisture.
Eco-Friendly Agricultural Technologies
Page Revised on Oct. 2009
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