Micro irrigation methods in response to crop production

1. Productivity of Field Crops Under Micro-Irrigation

2. Content
 Micro-irrigation: rationale
 Micro-irrigation : forms
 Drip irrigation
 Sprinkler irrigation
 Research findings
 Conclusions
 Future line of work

3. Global water resource scenario
 Less than 0.08% of Earth’s water is available to humans
 Only 2.5% of world water is fresh; 69% of that is locked in icecaps and
glaciers, 30% as ground water, 1% as soil moisture fresh water lakes
 Of the remaining, 20% is in remote areas, and much of the rest arrives at
wrong time and places
 One-third of global population faces water shortage
 Over the next two decades the demand will increase by 40%
Ministry of Water Resources, Government of India (2013)

4. Water resource scenario in India
Resources Quantity (km3 yr-1)
Average annual precipitation 4000
Average precipitation during monsoon 3000
Natural run-off (considering both surface and
ground water as single unit)
1953
Estimated utilizable surface water resources 690
Total replenishable ground water resources 432
Net utilizable groundwater resources 325
Groundwater potential available for domestic,
industrial and other uses 71 (approx)
Ministry of Water Resources, Government of India (2013)

5. FAO,2013
Sectoral water use in India

6. 5177
2209
1820
1545
1341
1140
0
1000
2000
3000
4000
5000
6000
1951
1961
1971
1981
1991
2001
2011
2021
2031
2041
2051
2061
Reducing per capita water availability
Per capita water availability in m3 /year
Water stress 1700 m3/capita/year
Water scarcity 1000 m3/capita/year
At present, the per capita water availability is about 1545 cubic
meter, which is slightly lower than the water stress level of 1700
cubic meter(2011 Census).
Per capita water availability in India

7. IT’S TIME TO GIVE A SERIOUS
THOUGHT for WATER?

8. Irrigating Land
Or
Crops ???

9. Irrigation is the artificial application of water to soil for the purpose of supplying the
moisture essential for normal plant growth and development.
Conventional method of irrigation (Flood irrigation) is the application
of water to the cropland without any preparation of land and without any levees to guide or
restrict the flow of water on the field.
 Only about 20 per cent of water is actually used by plants and the rest is being lost as
run off, seepage and evaporation
 Levelling of land increases cost of cultivation
 This method is unsuitable for crops that are sensitive to water logging
 Crop growth is not uniform as the water distribution by this method is very uneven
 There is a possibility of soil erosion
Drawbacks of Flood Irrigation

10. micro irrigation
Frequent application of small quantities of water directly
above and below the soil surface {root zone} usually as
discrete drops, continuous drops, tiny streams, or micro
spray; through emitters or applicators placed along a water
delivery line

11. 3.09
4.94
7.73
10.25
0
2
4
6
8
10
12
2005 2010 2015 2018
M
ha
All India Area Covered Under
Micro Irrigation; 2005-2018
4.78,
47%
5.47,
53%
All India Area Covered Under
Micro Irrigation by Segments;
2018
(Mha)
Drip Irrigation Sprinkler Irrigation
Department of Agriculture, Cooperation & Farmers
Welfare (2018)

12. 2.29
11.51
10.9
5.81
6.37
0.3
2.93
4.12
0.22
1.64
16.08
4.34 4.55
7.05 6.44
5.65
2.28 0.91
2.75
0.58
0
2
4
6
8
10
12
14
16
18
20
Lakh
ha
Drip Irrigation Sprinkler Irrigation
Major States Area Covered Under Micro Irrigation by Segments; 2018
Department of Agriculture, Cooperation & Farmers Welfare (2018)

13. Potential for drip and sprinkler irrigation in India
Crops Area (M ha)
Drip Sprinkler Total
Cereals - 27.6 27.6
Oilseeds 3.8 1.1 4.9
Pulses - 7.6 7.6
Vegetable 3.6 2.4 6.0
Cotton 7.0 1.8 8.8
Fruits 3.9 - 3.9
Total 27.0 42.5 69.5
GOI (2004)

14. Types of drip irrigation systems-
 Surface drip irrigation
 Subsurface drip irrigation
Drip irrigation is the process of slow application of water
in the form of continuous, discrete drops, tiny stream or
miniature sprays through mechanical devices called
emitters near the root zone of plants.
Drip Irrigation

15. Components of Drip Irrigation System

16. Surface drip
Lateral lines are laid on the surface
Most popular method for wide spaced crops
Ease of installing, inspecting, changing and
cleaning emitters
Interfere with cultural operations
•Laterals buried below soil surface
•Freedom from installing and removing
•Little interference with cultural operation
•Longer economic life
Subsurface drip

17. Advantages of drip irrigation
 Increased beneficial use of available
water
 Enhanced plant growth and yield
 Reduced salinity hazard
 Improved fertilizer and chemical
application
 Limited weed growth
 Reduced operational labour
 Decreased energy requirements
 Improved cultural practices
Limitation of drip irrigation
 High initial cost
 Susceptible to clogging
 Salt accumulation near plants
 May require better management
and technical knowledge
 Restricted root development and
water distribution

18. Sprinkler Irrigation
Also known as overhead irrigation
Types of sprinkler irrigation-
Permanent
Semi permanent
Portable
Semi portable
It is the application and distribution of water over the field
in the form of spray created by expelling water under
pressure from a nozzle. It is simulated series of rainfall.

19. Components of Sprinkler Irrigation System
 Pump unit
 Tubings- main/submains and laterals
 Couplers
 Sprinkler head
 Valves, bends, plugs, and risers

20. Advantage of sprinkler irrigation
 Can be used in sandy, slopy
and shallow soils
 Elimination of channel, bund
and conveyance losses
 Higher water use efficiency
 Maintains favourable
microclimate in crop field
Limitations of sprinkler irrigation
 High initial cost
 High maintenance requirements
 Cannot be operated in high wind
areas
 Salt injury in sensitive crops
 Not ideal for crops sensitive to
fungal diseases

21. Micro sprinklers
• These are highly useful for high discharge requirements in case
of orchards and also where the crop canopy as well as the root
zone spread is more
• They are normally, designed to spray water to cover an area of
1 to 6 meters with a flow rate varying from 20 lph to 120 lph

22. Rain gun
 Most suitable for a variety of climates like tropical, temperate and humid climates as in
India
 Light in weight and easy to install
 Uniform distribution profile with adjustable jet
 Long life span and low maintenance
 Better pattern coverage & good performance in windy conditions

23. • Irrigation Efficiency: 88%
• Operating Pressure: 15 psi
• Outlet Spacing: <5ft
Low Elevation Spray Application (LESA)
Mid Elevation Spray Application (MESA)
• Irrigation Efficiency: 78-88%
• Operating Pressure: 25 psi
• Outlet Spacing: 10ft

24. Low Energy Precision Application (LEPA)
• Irrigation Efficiency: 95 %
• Operating Pressure: 15 psi
• Outlet Spacing: 60-80 Inches

25. Nutrient
Fertilizer Use Efficiency
(%)
Soil
application
Fertigation
Nitrogen 30-50 95
Phosphorous 20 45
Potassium 50 80
Senthil (2009)
Fertilizer Use Efficiencies Under Various Application Methods

26. water and fertilizer operating cost saving
Ability to apply saline water
Operate on steep slopes
Easy to automate
Adaptable for chemigation
Reduced weed growth
Advantage of micro irrigation

27. Conclusions
 Micro-irrigation is a potential water and nutrients-saving option. Its
adoption may lead upto 50% saving in irrigation water in cereals (mainly,
rice, wheat, maize), occupying almost 70% of the arable land in India.
 This technique would not only reduce the wastage of water, but also
enhance the crop productivity and resource-use efficiency on a long-term
basis, in spite of the initial high cost.
 Integrating micro-irrigation techniques with other on-farms water-saving
options like mulches result in better soil and water conservation, higher
crop productivity and resource-use efficiency.

28. Future line of work
 Awareness and wider publicity among the farmers for
improving water productivity at their farms
 Development of low cost micro irrigation systems for wider
adoption
 Interactions optimization between nutrients and irrigation
and impact assessment in different cereals crops through
large number of on-station and on-farm experiments