our irriation technician davison will take us through a series of irrigation studies. hope you are alert to learn.
What is Irrigation?
Irrigation is the artificial
application of water to terrain to support the agricultural industry, including
crop growth. Although there is a vast amount of water available on the planet,
only a small portion of it can be utilized for irrigation purposes. Irrigation
has been practiced since the Agricultural Revolution and has grown and
developed into complex systems. Today, agriculturalists must take into
consideration the costs and benefits of utilizing an irrigation system before
they make the decision to have one installed.Objectives of Irrigation
1. To add water to the plant
root zone for plant growth (this is usually the main objective);
2. To cool the soil and or air
around the plants, creating a more favorable micro-environment for plant
growth;
3. To reduce or eliminate the
detrimental effects of short-duration frost (using sprinklers);
4. To maintain the relative
humidity of the micro-climate around the plants;
5. To leach or dilute salts in
the soil;
6. To soften hard pans and soil
clods;
7. To delay bud formation
through evaporative cooling;
8. To dispose of effluent from
farms and ranches; and,
9. To apply fertilizers or soil amendments.
Advantages of Irrigation:
• Increase in crop yield
Irrigation has increased the
productivity of rain-fed land by as much as five times in tropical countries.
On an average, the yield from
irrigated land is about 2.5 t/ha; while that from unirrigated (rain-fed) land
about 0.5 t/ha.
• Protection from famine (in
drought prone areas)
• Elimination of mixed cropping
Mixed cropping means growing
two or more crops simultaneously in the same field.
Advantage: If the weather
conditions are not suitable for one crop, they may be suitable for the other
crops and thus the farmer will get at least some yield from the same field.
Disadvantages:
Requirements for
the field preparation, manure application, watering, etc. for different crops
are different. As it is impossible to cater to the needs of two or more crops
in the same field, the yield of the crops is low. At the time of harvesting,
the crops get intermixed, reducing the purity of each crop.
• Increase in revenue and
saving foreign exchange
• Canal plantation
Trees can be planted along the
canal on the banks and on the open land available between the canal and the
agricultural fields. The trees plantation increases the timber wealth and
associated products. This checks soil erosion and keeps the ecological balance.
• Facilities of communication
An inspection road on one of
the banks of the canal provides a good communication link for the villagers who
use it for walking, cycling, riding or even motoring. In some cases, the tops
of embankments of canals are also used as pathways.
• Inland navigation
ILL-Effects of Irrigation
• Water-logging
Over-irrigation may lead to
water logging and may reduce crop yield.
The soil pores become fully
saturated and the normal circulation of air in the root zones of the crops is
stopped and the growth of the crops is decreased.
When the water table reaches
the ground surface, the land becomes saline. The ground water brings salts with
it and these salts are deposited on the ground surface after the water
evaporates. The land ultimately becomes unfit for cultivation.
• Damp climate
Because of intensive
irrigation, the climate of the region becomes quite damp and cold. Under such a
climate, the body resistance to diseases is considerably decreased and outbreak
of various diseases may occur.
• Mosquitoes nuisance
Due to excessive application of
water and leakage from canals, the pits and depressions get filled up with
water. These stagnant pools of water act as breeding places for mosquitoes and
the region becomes malaria prone.
Remedy for Ill-Effects of Irrigation
• The ill-effects of irrigation
are mainly due to defective planning and unscientific use of water.
• These ill-effects can be
effectively reduced and sometimes altogether eliminated by exercising
economical and scientific use of water.
• All the aspects of an
irrigation project should be properly studied and implemented.
• If necessary, various command
area development work should be simultaneously undertaken.
•
Domestic water supply
• Generation of hydro-electric power
