Abstract:
What is Drip Irrigation?
Drip irrigation, also known as trickle irrigation or micro irrigation
or localized irrigation, is an irrigation method that saves water and fertilizer
by allowing water to drip slowly to the roots of plants, either onto the soil
surface or directly onto the root zone, through a network of valves, pipes, tubing,
and emitters. It is done through narrow tubes that deliver water directly to the
base of the plant.
Why should I use drip irrigation?
Drip irrigation saves water because little is lost to runoff or evaporation.
This watering method also promotes healthy plant growth, controls
weed growth, and reduces pest problems.
Irrigation methods are commonly designated according to the manner
in which water is applied to the land to be irrigated.
Surface Irrigation Methods
The water is applied by spreading in it sheets or small streams on
the land to be irrigated.These methods are adopted for perennial irrigation system.
Sprinkler Irrigation Methods
The irrigation water is applied to the land in the form of spray, somewhat
t as in ordinary rain.It can be used for all the crops except rice
and jute and for almost all soils except very heavy soils with very low filtration
rates.
Sub-Surface Irrigation Methods
The water is applied below the ground surface so that it is supplied
directly to the root zone of the plants.The main advantages of these methods are
that the evaporation losses are considerably reduced and the hindrance caused
to cultivation by the presence of borders, pipes and field channels in the other
methods of irrigation is eliminated.
ADVANTAGES
Reduced water use
Because drip irrigation brings the water to the plant root zone and
does not wet the entire field, drip irrigation typically requires half to a quarter
of the volume of water required by comparable overhead-irrigation systems.
Joint management of irrigation and Fertilization Drip irrigation can
improve the efficiency of both water and fertilizer. Precise Application of nutrients is possible
using
drip irrigation. Hence, fertilizer costs and
soluble nutrient losses may be reduced with drip irrigation. Nutrient applications
may also be better timed to meet plant needs.
Reduced pest problems
Weed and diseaseproblems may be reduced because drip irrigation does
not wet the row middles or the foliage of the crops as does overhead irrigation.
Simplicity Polyvinyl chloride (pvc) and polyethylene parts are widely available
in several diameters and are easy to assemble. Many customized, easy-to-install
connectors, endcaps, and couplers are available in different diameters. Cutting
and gluing allows for timely repairs.
Low
pumping needs
Drip systems require low operating pressure (20-25 psi at field entrance,
10-12 psi at the drip tape) compared to overhead systems (50-80 psi). Many existing
small pumps and wells may be used to adequately irrigate small acreage using drip
systems.
Automation
Drip-irrigation application may be simply managed and programmed with
an AC- or battery-powered controller, thereby reducing labor cost.
Adaptation
Drip systems are adaptable to oddly shaped fields or those with uneven
topography or soil texture, thereby eliminating the underutilized
or non-cropped corners and maximizing the use of available land.
Production advantages
Combined with raised beds, polyethylene mulch, and transplants, drip
irrigation enhances earliness and crop uniformity. Using polyethylene mulch also
increases the
Cleanliness of harvested products and reduces the risk of contamination
with soil-born pathogens. Reflective mulches further help reduce the incidence
of viral diseases by affecting insect vectors, such as thrips, whiteflies or aphids.
DISADVANTAGES
Drip irrigation requires an economic Investment
Drip-irrigation systems typically cost $500 - $1,200 or more per acre
.Part of the cost is a capital investment useful for several years, and another
part is due to the annual cost of disposable parts. Growers new to drip irrigation
should start with a relatively simple system on a small acreage before moving
to a larger system.
Drip irrigation requires maintenance and high-quality water
Once emitters are clogged or the tape is damaged, the tape must be
replaced. Water dripping from an emitter and the subsequent wetting pattern are
hard to see, which makes it difficult to know if the system is working properly.
Proper management of drip irrigation requires a learning period.
Water-application pattern must match planting pattern
If emitter spacing (too far apart) does not match the planting pattern,
root development may be restricted and/or plants may die.
Safety
Drip tubing may be lifted by wind or may be displaced by animals
unless the drip tape is covered with mulch, fastened with wire anchor pins,or
lightly covered with soil.
Leak repair
Drip lines can be easily cut or damaged by other farming operations,
such as tilling, transplanting, or manual weeding with a hoe. Damage to drip tape
caused by insects, rodents or birds may create large leaks that also require repair.
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