Introducing: Drip Irrigation By Prof' Alon Tal, BGU

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Introducing Drip IrrigationBy Prof. Alon Tal,
BGU
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FAO - October 2005,
39 countries face serious food shortages (25
in Africa, 11 in Asia/Near East 2 in Latin
America 1 in Eur.) Worlds farmers face water
deficit 160 billion m3 /yr (amount used to
produce 10 of world's grain.)
Conclusion Irrigated agriculture needs to play
significant role in addressing food nutrition
gaps
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Water and Agriculture,

• In 2000, agriculture accounted for 67 of world's
  total water withdrawal -- 86 of consumption
  (UNESCO, 2000)
• In Africa and Asia, 85-90 of all the freshwater
  used is for agriculture
• Global demand for food, by 2025,
• expected to increase water demand
• agriculture 1.2 times,
• industry 1.5 times
• domestic consumption 1.8 times

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Irrigation practiced on gt 250 million ha
worldwide. This 17 of cultivated lands.
But irrigated lands produce 40 of agricul.
outputs! Ironically rate of expansion of
irrigated lands since late 1970s has declined
heavily.
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Top 10 countries utilize 67 of worlds
agricultural areas
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Conventional irrigation hypothesis soil
moisture remains equally available to crops
until plant roots deplete it to some residual
low value called the permanent wilting point
(Veihmeyer and Hendrickson, 1950).
Implications regimen of infrequent
irrigation designed to wet soil periodically to
maximal field capacity and then let crop roots
deplete soil moisture to wilting point of plants
before irrigating again.
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Micro-irrigation an irrigation method that
applies water slowly to roots of plants, by
depositing water either on the soil surface or
directly to the root zone, through a network of
valves, pipes, tubing, and emitters.
Application of smaller amounts of water w/
frequency
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Components of micro irrigation system
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• End of 1950s low cost plastics makes it
  possible.
• 1959 Simcha Blass introduces first system.
• Previous systems water released through tiny
  holes, blocked easily by tiny particles,
• Blass innovation water released through larger
  and longer passageways -- using friction to slow
  water flow rate inside plastic emitter.
• 1965 Netafim Corporation established at Kibbutz
  Hatzerim.
• Israels 50th anniversary voted best
  invention.

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On-line and In-line Drippers
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Micro Sprinklers/Sprayers
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Filters
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Control Equipment
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During past 30 years, diffusion of micro
irrigation systems increased from 1.1 in 1986 Mha
to more than 6 Mha in 2006.
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Micro Irrigation Coverage Americas (1.9 Mha)
Europe (1.8 Mha) Asia (1.8 Mha) Africa (0.4
Mha) Oceania (0.2 Mha).
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Micro Irrigation - Usage Primarily to increase
production of high value fruits, vegetables,
herbs and commercial flowers
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Drip Irrigation Benefits

• Evaporation reduced relative to sprinklers
• Irrigates steep landscapes.
• Eliminates drift during wastewater reuse.
• Allows for precise chemigation.
• Delivers to root zone.
• Automation optimization

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Drip Irrigation Benefits

• Water use per yield drops dramatically.
• Improved quality of production
• Less fertilizer and weed control costs
• Environmentally responsible
• reduced leaching run-off
• Labor saving

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Drip Irrigation Disadvantages

• Expensive
• Requires managerial skills
• Waste plastic tubing and "tapes" generally last
  3-8 seasons
• before being replaced
• Clogging of radia
• Plant performance
• Studies indicate many plants grow
• better when leaves are wetted

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Groundwater Salination Not Eliminated
Israel Water Authority, 2008
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Protected agriculture

• Increasingly used in greenhouses
• Especially in hyper-arid zones.
• (internationally 0.75 Mha growing)
• Evapotranspiration minimized.
• Cooling in summers /warming
• on winter nights required.
• Drip irrigation makes
• it feasible.

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Subsurface drip irrigation The Next Generation

• Conserves water while
• controlling weeds,
• minimizing runoff and evaporation,
• increasing longevity of laterals and emitters,
• easing use of heavy equipment in field, and
• preventing human contact w/ low-quality water.
• labor saving (avoids seasonal installation).

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Economics

• India payback period for sugarcane crop using
  micro irrigation 1.4 years.
• Affordable Micro Irrigation Technologies
  (AMITs) now used in developing countries.
• Available as packaged kits suitable for small
  fields (0.02 to 0.4 ha).
• Presently, AMITs used on 50,000 hectares by
  gt250,000 smallholders.