PPT on Drip Irrigation presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
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Language: en
Added: Jun 13, 2024
Slides: 62 pages
Slide Content
Drip Irrigation Technology
in Crop Production
Chamila Perera
Assistant Director of Agriculture (Research) -Soil and Water Management
Field Crops Research and Development Institute -Sri Lanka
Content
▪Importance of drip irrigation
▪Different types of drip irrigation
▪Components of drip irrigation systems
▪Maintenance of drip systems
▪Drip irrigation based crop
management packages
▪Further developments
▪Technology dissemination
Irrigationhasthepotentialtoprovidehigheryieldsthanrainfedagriculture.
Source:FAOpublicationsonwatermanagement
Impact of irrigation on crop productivity
Drip irrigation :
Supplying water to the soil very close to
the plants at very low flow rates through
emitters.
FAO Training Manual -05
Benefits of drip irrigation
▪Reduced water losses
▪Increased water use efficiency
▪Fertigation possibility
▪High efficiency (labour/ energy)
▪Land grading & leveling not required
▪Possibility of measuring water usage
▪User friendly operation
Components of a typical drip irrigation system
▪Water source
▪Water pump
▪Head controlling unit -
Filter/ Fertigation unit/ Air relief valve/ Pressure gauge/ Controlling
valves
▪Field irrigation system
Polyethylene tubes with Inline emitters
▪Fixed emitter spacing
▪Higher durability compared to the drip tapes
Polyethylene tubes with
Online emitting devices
▪Customized emitter spacing
▪Replaceable
Technology Development
Inline drippers Inline NPC drippers Inline PC drippers
Online drippersOnline NPC drippersOnline PC drippers
Online PC
Self Flushing
drippers
▪Suitable for potted plants
Stake drippers
Other localized irrigation types
Bubblers
▪Discharge -Approx. 25 -40 LPH
▪Suitable for orchard crops
Spray -jets
Not only the water, but also the uniform fertilizer distribution
in the root zone is very important in the fertigation
Practices.
Selecting the appropriate emitter type
ABC
0.2 bar0.6 bar1.0 bar
Source:
Drip
Research
Technology
Solutions
(DRTS)
PC:Pressure
compensated
Non-PC:Non pressure
compensated
PCND:Pressure
compensated non
drained
Water distribution in different soil types
under drip irrigation
Ideal
distribution pattern
Designing an appropriate layout for a drip system
-Clay soils
Planting bed
Designing an appropriate layout for a drip system
-Excessively well drained soils
Planting bed
Accessories for
the drip irrigation systems
Disk filters
▪More efficient in filtration
▪Suitable for small scale drip irrigation
Filters
Screen filters
▪A commonly used filter type
▪Suitable for small scale sprinkler irrigation systems
Sand media filters
Hydro cyclone flirters
▪Suitable for large scale irrigation systems
Fertilizer tanks Fertigation equipments
▪Higher durability
▪Suitable for large scale irrigation systems
Venturi injectors
▪Suitable for small scale
irrigation systems
Ball valves
Valve
s
▪Release trapped air in the system▪Control water flow
Air release valvesControl valves
Other fittings
Maintenance of the
drip irrigation systems
Water source :
Agro-well
▪Water quality
▪Runoff blocking
▪Cement lining
▪Covering with nets
▪Cleaning
Water class
Electrical
conductivity
(dS/ m)
Salt
concentration
(mg/ l)
Type of water
Non-saline < 0.7 < 500 Drinking and irrigation water
Slightly saline0.7 -2 500 -1500 Irrigation water
Moderately saline2 -10 1500 -7000
Primary drainage water and
groundwater
Highly saline 10 -25 7000 -15 000
Secondary drainage water
and groundwater
Very highly saline25 -45 15 000 -35 000Very saline groundwater
Brine > 45 > 45 000 Seawater
Source: FAO Irrigation and drainage paper -48
Water quality
▪Filter cleaning
▪Emitter cleaning
-Physically
-Chemically
-Acids -For salts (Phosphoric acid)
-Chlorination -For algae
▪Flushing the pipes
▪Storage in off season
▪Security - Rodents/ Dogs
Other maintenance
Component
Head requirement
Bar Feet
Minimum inlet pressure 0.50 16.5
Average depth of the water table commonly observed in the
shallow wells in Sri Lanka (15 -20 feet)
0.60 20.0
Average vertical elevation differences from the surface level of
the shallow well and the field level
0.30 10.0
For the disk filter and the venturi system in the drip system0.30 10.0
Average head losses in the pipe system (around 50 m long) 0.15 5.0
Total dynamic head requirement of the pump at operation 1.85 61.5
Pump capacity requirement for smooth functioning of
the drip systems -Operating head & Discharge rate
The required discharge rate at the operation head is depended on the number of emitters
operated at a given time.
Ex. If 3000 of 2 LPH emitters are operated then, the required discharge is 6000 LPH.
Then, a pump with a discharge rate of 6000 LPH @ 1.85 bar pressure is most suitable for this
requirement.
Drip irrigation based
crop management packages
-
Experiences in Sri Lanka
Realizable potential yields of crops
Farmer average yields of crops
Agronomic
best
management
packages
While
conserving
natural
resources -
soil
water
Challenge
Increased crop productivity of crops
Fertigation
Split
application
of fertilizer
Micro
nutrients
Components of micro irrigation system based
agronomic management packages
MulchingRaised beds
Micro irrigation -Drip systems
High yielding
varieties
Organic
matter
Agronomic
management
package for chilli
under drip irrigation
▪Yields - Around 45 t/ ha of green chilli from hybrids
▪Water productivity -50 % increase compared to surface irrig.
▪Labour saving -Irrigation and Weeding
▪Energy saving in irrigation
Package
▪Drip irrigation
▪Cattle manure -15 t/ ha
▪Straw mulching - 5 t/ ha
▪Split application of
fertilizer through
fertigation
Smartness in agriculture
Drip based
management
package
Water smart √
Energy smart √
Carbon smart √
Nitrogen/ Nutrient smart √
Weather smart √
Knowledge smart √
Smart Agriculture technologies/ practices
Case study -
Drip irrigation based chilli cultivation package
Area: Anuradhapura
Component LKR
Total cost 665,500.00
Total income 2,677,690.00
Profit 2,012,190.00
Profit with the
depreciated cost for the
drip system*
2,282,190.00
* The drip system will be used for 10 seasons
and thus the cost of the drip system per
season is LKR 30,000.00
Costs -Benefits
USD 1 = LKR 300
Yield (t/ ha) -11 months
(35 -40 picks)
Max. Min. Average
65 30 45
Agriculture Sector Modernization Project
-ASMP
Smallholder Agribusiness Partnership
Programme -SAPP
Average yield :
50 -60 t/ ha
Agronomic
management
packages for onion
under drip irrigation
▪Yields - Around 40 t/ ha
▪Water productivity -50 % increase compared to surface irrig.
▪Labour saving -Irrigation and Weeding
▪Energy saving in irrigation
Package
▪Drip irrigation
▪Cattle manure -15 t/ ha
▪Straw mulching - 5 t/ ha
▪Split application of
fertilizer through
fertigation
Farmer adoption -
▪Interprovincial Agriculture Extension Service
▪Provincial Department of Agriculture -Central
Province
▪Mahaweli Authority of Sri Lanka
▪Agriculture Sector Modernization Project
Yala 2021 -Yala
2023
•Majority of farmers obtained -> 30 t/ ha yields
•Some have achieved -40 t/ ha
•Average profits -> LKR 300 000/ 0.25 ac.
•Some have obtained -> LKR 500 000/ 0.25 ac.
Programme Unit area (ac.) Number
Demonstrations 0.25 28
ASMP 0.25 50
Sayubhagya 0.25 259
Sayubhagya 0.5 38
Total 375
USD 1 = LKR 300
Big onion true seed production under drip irrigation
Private sector involvement
Keels Pvt. Ltd./ Cargills Pvt. Ltd.
20 different types of crops
Further developments
Water pump
Controlling unit
Soil moisture sensors
Irrigation system -Crop
Automated irrigated systems
Solar power for irrigation -Sustainable green energy
in agriculture
Factors to be considered -
▪Capacity -Head/ Discharge
▪Durability
▪Efficiency -
•Operating under low light intensity
(DC/ Brushless)
Usage of the micro irrigation in the region
FAO Waters Reports - 37
Irrigation in Southern and East Asia in Figures -2011
Technology dissemination strategies
▪Field demonstrations
▪Visits on successful farm fields
▪Video/ Audio programmes (TV/ Radio/ You
Tube)
▪Social media (FB/ WhatsApp groups)
▪Leaflets/ Booklets
▪Street drama
▪Individual meetings with farmers
▪Hands on training