Irrigation Management

1. UNIVERSITY OF AGRICULTURAL SCIENCES
GKVK BANGALORE 560065
PRACTICAL CROP PRODUCTION-II(IRRIGATED)
AGR 212 (0+1)
TOPIC:IRRIGATION MANAGEMENT
SUBMITTED TO;
Dr. PUSHPA K
DEPT OF AGRONOMY
COA ,GKVK,BANGALORE

2. GROUP MEMBERS
AMB0001 AASHIK KHANAL AMB0006 AFROZNAJNEEN KAROBARI
AMB0002 ABHIJNA V AMB007 AHDAL NIYAS
AMB0003 ABHISHEK T NAIK AMB0008 AISHWARYA
AMB0004 ADARSH AMB0009 AISHWARYA S
AMB0005 ADARSH R MUDNAL

3. WHAT IS IRRIGATION?
It is the artificial application of water to the soil through various
system of tubes , pumps and sprays.
Irrigation is usually used in areas where rainfall is irregular or dry
times or drought is expected.
Irrigation water can come from ground water , surface water ,through
springs or wells , through rivers , lakes or reservoirs.

4. WHY IRRIGATION IS REQUIRED?
To complete the normal life cycle of plant.
To improve the crop growth and quality.
For the absorption of nutrients by plants from soil.
For seed bed preparation.
Protective role during periods of famine droughts.
For effective germination.

5. NECESSITY OF IRRIGATION
Insufficient rainfall.
Uneven distribution of rainfall.
Improvement of perennial crops.
Development of agriculture in desert area.

6. IRRIGATI0N MANAGEMENT
Management of water based on the soil and crop
environment to obtain better yield by efficient use of water
without any damage to the environment.
An endeavour to make irrigation as
a useful, profitable, productive
practice by adopting the right
method,at right time by estimating
appropriate quantity of water.

7. IMPORTANCE OF IRRIGATION MANAGEMENT
To the development of nation through proper management of water
resources for the purpose of crop production and other activities
such as industrialization, power generation , etc.
To store and regulate the water resources for future use or non-
season use.
To apply sufficient quantity to field crops.
To allocate the water with proper proportion based on area and crop
under cultivation.
To convey water without much loss through percolation and
seepage.
To meet the future requirement of agriculture and other sections.

8. AREA UNDER IRRIGATION
The world’s total area equipped for irrigation was estimated at 341,723
thousand hectares.
China has the highest area under irrigation ie.,69 mha.
India stands second with 64.7 mha.

9. IRRIGATION IN INDIA
Irrigated area accounts for
48.8% of the 140 mha of
agricultural land in India.
UP has the largest area
under irrigation-17.6 mha.

10. SOURCES OF IRRIGATION
Main sources of irrigation includes canals,tanks and wells.
Main source of irrigation in India is tube-wells which provide 46% of
water for irrigation.
Canals are second most important source of irrigation in India after
wells and tube-wells.

11. IRRIGATION SCHEDULING
It is defined as a comprehensive plan indicating time of irrigation, duration
of irrigation, frequency of irrigation, number of irrigation and quantity of
irrigation for a given method of irrigation for a given crop.
Irrigation scheduling is also defined as the frequency at which water is to be
applied based on needs of the crop and nature of the soil.

12. FACTORS TO BE CONSIDERED IN IRRIGATION SCHEDULING
Type of crop, its duration, nature and its water requirement.
Area under consideration.
Soil type, its texture, Bulk density and WHC.
Gradient, method of irrigation adopted, application and distribution efficiency.
Method of conveyance of water, conveyance efficiency.
The discharge available, period of availability of water.
Moisture depletion level allowed between irrigations.

13. METHOD OF IRRIGATION SCHEDULING
1.FEEL AND APPEARANCE METHOD
 It is the simplest method where farmers estimate the approximate soil
moisture content through feel soil with fingers and its appearance
2.PLANT/CROP INDICES
 Plant shows different characteristic symptoms for different moisture
situation accordingly the irrigation is scheduled

14. 3.INDICATOR PLANTS
 When the soil moisture goes below the requirement , plants like
sunflower and tomato show wilting symptoms first due to their
sensitivity and the irrigation is scheduled accordingly.
4.PIT INDICATOR/PROFILE MODIFICATION TECHNIQUE
 Pit of 1m x1m x 1m is dug out in a crop field and the dug out soil
is mixed with additional 5% sand filled to the pit.Crops are
planted in the pit .
 At low moisture conditions plants in the pit shows wilting
symptoms first due to low water holding capacity of sand.

15. 5.WILTING SYMPTOM APPROACH
 Farmers plan to irrigate the crop on seeing visible wilting symptom.
6.CRITICAL STAGE APPROACH
 Stage at which water stress causes severe yield reduction is known as
critical stage of water requirement .
 moisture stress during critical stage will reduce the yield.
7.SOIL MOISTURE DEPLETION APPROACH
 When the available water in the root zone is depleted to a particular
level, it has to replenished by irrigation.

16. 8.IW/CPE RATIO APPROACH
IW-Irrigation water
CPE-Cumulative pan evaporation
 It is the ratio of irrigation water to the water that is lost by
evaporation.
 Main principle behind this approach is that an irrigation is supposed
to compensate the loss of water from soil profile due to evaporation.

17. CROP WATER REQUIREMENT
Estimation of crop water requirement is one of the basic needs for crop planning and for
planning any irrigation project.
The quantity of water required by a crop in a given period of time for its normal growth
under field condition .
CWR=E.T/C.U+APPLICATION LOSSES+SPECIAL NEEDS
IR = CWR –(ER+S)
IR=IRRIGATION REQUIREMENT
CWR=CROP WATER REQUIREMENT
ER= EFFECTIVE RAINFALL
S= GROUND WATER CONTRIBUTION
E.T- EVAPOTRANSPIRATION
C.U- CONSUMPTIVE USE (TOTAL WATER REQUIRED FOR ALL PLANT PROCESS)

18. IRRIGATION EFFICIENCY
It is the ratio of amount of water used to meet the ET requirement of
the crop plus that necessary to maintain a favourable salt balance in
the crop root zone to the total volume of water diverted, stored or
pumped for irrigation.

19. TYPES OF IRRIGATION EFFICIENCY
1.Conveyance efficiency
Ec=(Wf /Wd) ×100
Ec=Conveyance efficiency
Wf=Water conveyed to the plot
Wd =water delivered at source

20. 2. Application efficiency
Ea=(Ws/Wf) ×100
Ea=application efficiency
Ws=Water stored in the root zone
Wf=Water let into the field

21. 3. Storage efficiency
Es=(Ws/Wn)×100
Es=storage efficiency
Ws=Water stored in the root zone after irrigation
Wn= Water need in the root zone prior to irrigation

22. 4. Water distribution efficiency
Ed=(1-(y/d)) ×100
Y=Average numerical deviation from d
d=Average depth of water stored in the field

23. 5. Water use efficiency (WUE)
It is defined as the amount of water used to produce unit quantity of biomass or yield.
It is of 2 types
1. Crop water use efficiency
2. Field water use efficiency

24. 1. Crop water use efficiency(CWUE)
CWUE = Y
ET
Y = yield (kg)
ET = Evapotranspiration (cm or mm)
The unit to measure the CWUE is kg/cm or kg/mm.

25. 2.Field water use efficiency (FWUE)
FWUE = Y
WR
Y = yield (kg)
WR = Water requirement (cm or ha-cm)
 It is expressed as kg/ha-cm.

26. METHODS OF IRRIGATION

27. 1.Surface irrigation
Here water is allowed to flow all along the surface of the soil horizontally
through gradient / slope and vertically by gravity flow to the crop root 𝘻𝘰𝘯𝘦.
Surface irrigation is the most popular and convenient method.
 It is normally used 𝘸𝘩𝘦𝘯
a) mild and regular 𝘴𝘭𝘰𝘱𝘦𝘴
b) soil type with medium to low infiltration rate
c) a sufficient supply of surface or groundwater

28. Advantages
a) Convenient and suitable for most of the crops & soils
b) Easy and doesn’t require any pump
Disadvantages
a) Involves land shaping –fertility losses & high cost due to soil cutting
b) Conveyance loss (Seepage, percolation, evaporation) is very high
c) Improper / non-uniform distribution of water
d) May result in saltation, water logging, salinity
e) Irrigation efficiency is very low

29. a) Free flooding
 Primitive method of allowing the water freely on the surface with natural
gradient without any land shaping.

30. b) Border irrigation
 The land is divided into number of long parallel strips called borders.
 These borders are separated by low ridges.
 The border strip has a uniform gentle slope in the direction of Irrigation.

31. Types of border strips
1. Straight border strips
When the borders are laid straightly along the general slope of field they are
called straight borders or down the slope borders.
2. Contour border strips
When the land is having more slope and fields are undulating and levelling
is not feasible, borders may be laid across the slope and are called as
contour border strip.

32. C) check basin irrigation
 It is the most common method of irrigation in India and in many other countries.
 Here the field is divided into smaller unit areas so that each has a nearly level surface.
 Bunds or ridges are constructed around the areas forming basins within which the irrigation
water can be Controlled.

33. Types of check basin method of Irrigation
1. Rectangular check basin – Suitable for relatively levelled lands for closely spaced
crops.
2. Contour check basin – Suitable for sloppy lands and basins are formed across the
slope.
3. Ring check basin – Suitable for widely spaced orchard crops, where wetting is needed
around the trunk of the tree.
- Basins are circular/ring in shape.

34. d) Ridges and Furrow method
 This method is used in the irrigation of widely spaced row crops like maize, sugarcane,
potato, tomato, tobacco, banana etc.
 ‘V’ shaped furrows are opened between crop rows.

35. Types of ridges and furrow method of Irrigation
1. Deep ridges and furrows
2. Corrugated ridges and furrows/ Corrugation
3. Serpentine method
4. Surge irrigation

36. 1. Deep ridge and furrow
Deeper furrows of 15-30 cm spaced 90 cm apart are made in straight line or along the
contour (when slope is >1%).
It is suitable for crops with deep root system with high water requirement

37. 2.Corrugation:
It consists of small furrows in ‘V’ shaped of about 6 to 10 cm deep spaced 40 to 75 cm apart
which helps in irrigating the water along the slope.
It is commonly used for irrigating non cultivated, close growing crops like small grains & for
pasture growing on steep slopes with low water requirement.

38. 3.Serpentine method of irrigation
It is ridge and furrow system with inter connection of furrows in serpentine way.
The entry of water in one furrow ensures that several furrow are irrigated automatically.
This is a useful method when gradual slope of 0.2 – 0.5% is created in one direction
perpendicular to the direction of furrow.

39. 4.Surge irrigation:
It is also called as On and Off type of Irrigation.
Surge irrigation is the application of water into the furrows intermittently in a
series of relatively short ON and OFF times.
The irrigation efficiency is in between 85 and 90%.

40. 2. Sub surface irrigation
In subsurface irrigation water is applied beneath the ground by creating and maintaining an
artificial water table at some depth, usually 30-75 cm below the ground surface.

41. Advantages
1. Less water requirement – low evaporation and deep percolation losses
Disadvantages
1. There is danger of development of waterlogging
2. Possibility of choking of the pipes lay underground.
3. High cost.

42. 3.SPRINKLER IRRIGATION
The sprinkler or overhead irrigation system consists of conveying water to the field by
aluminium or polyvinyl chloride (PVC) pipes and allowed to sprinkle over the field under
pressure through a system of nozzles.
This system is designed to distribute the required depth of water uniformly which is not possible
in surface irrigation.
Components of Sprinkler Irrigation
1. Motor pumping Unit
2. Mainline pipe Unit
3. Lateral pipe unit
4. Sprinkler Unit

43. Advantages
1. Economical use of water
2. Lower water loss
3. Effective water 𝘮𝘢𝘯𝘢𝘨𝘦𝘮𝘦𝘯𝘵
4.protect crops against frost and high temperature
5.Free aeration of root zone
6.Drainage problems eliminated
Disadvantages
1. High initial cost
2. Efficiency is seriously affected by windy weather
3. Higher evaporation losses in spraying water
4. A stable water supply is needed for the most economical use of the equipment
5. Higher power requirement
6. Excessive use of saline water on foliage is inadvisable

44. 4. DRIP IRRIGATION
 Drip or trickle irrigation is one of the latest methods of irrigation.
 It is suitable in water scarcity and salt affected soils.
 In drip irrigation method, water is applied frequently and at low volume ,so that it
approaches the consumptive use of the plants and minimizes losses such as deep
percolation, runoff and soil water evaporation.
 The system applies water slowly to keep the soil moisture within the desired range for
plant growth.

45. Advantages
1. Water saving losses due to deep percolation, surface runoff and transmission are
avoided.
Evaporation losses occurring in sprinkler irrigation do not occur in drip irrigation.
2. Uniform water distribution
3. No land leveling required
4. No soil erosion
5. Better weed control
6. Nutrient preservation
Disadvantages
1.High initial cost
2.Drippers are susceptible to blockage

46. Factors affecting a method of irrigation
Topography
Climate
Means of irrigation
 Type of crop
Soil factors
Economic factor
Water conservation
Weather factors