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1. FURROW IRRIGATION

2. Furrow Irrigation
Furrows are small channels, which carry water down
the land slope between the crop rows.
Water infiltrates into the soil as it moves along the
slope.
This method is suitable for all row crops and for
crops that cannot stand water for long periods, like 12
to 24 hours, as is generally encountered in the border
or basin methods of irrigation.

3. Furrow Irrigation
 Water is applied to the furrows by letting in water from the
supply channel, either by pipe siphons or by making temporary
breaches in the supply channel embankment.
 The length of time the water is to flow in the furrows depends on
the amount of water required to replenish the root zone
the infiltration rate of the soil
the rate of lateral spread of water in the soil.
 Furrow irrigation is suitable to most soils except sandy soils that
have very high infiltration water and provide poor lateral
distribution water between furrows

7.  Row crops such as potatoes, cotton, sugarcane,
vegetable etc. can be irrigated by furrow method.
 Water is allowed to flow in furrow opened in crop
rows. It is suitable for sloppy lands where the furrows
are made along contours.
 In sandy and clay loams, the length is shorter than in
clay and clay loams.
 Water does not come in contact with the plant stems.
There is a great economy in use of water.

8. Advantages:
 High water efficiency
 Can be used in any row crop
 Relatively easy in stall
 Not expensive to maintain
 Adapted to most soils.

9. Disadvantages:
1. Requirement of skilled labour is more
2. A hazard to operation of machinery
3. Drainage must be provided.

10. Kinds of Furrow Irrigation
● Level furrows
● Graded straight furrows
● Graded contour furrows
● Corrugations

11. Level Furrows
● Small irrigation channels
● Irrigation water must be applied quickly
● Using furrows as large as the stream can contain
● Require extensive land preparation
● Best suited for soils with moderate to slow intake rate

12. Advantages
● Adjustability of water quantity applied
● Doesn’t require change in land layout
● Efficient application
● No irrigation water needs to be lost from runoff
● Use of rainfall can be maximized

13. Disadvantages
● Difficult to apply in areas of high wind
● Water ponds damage some crops(potato)
● Drainage of rainfall can be extensive
● Furrow needs to be large enough to carry rainfall
excess
● Topography needs to be carefully and regularly
maintained

14. Graded Straight
● Small irrigation channels
● Relatively flat lands
● Usually constructed in straight lines
● Initial irrigation stream needs to be more than intake
rate in order for stream to advance
● Suitable for crops planted in rows

15. Advantages
● Can be used with both large and small
irrigation streams
● Furrows can act as channels to carry and
dispose excess surface water
● High application efficiency

16. Disadvantages
● High labor requirements (unless automated)
● Uniform application is difficult for soils with high
intake rates
● Land needs to be relatively flat and have very little
slope
● Field must be carefully leveled
● Surface runoff collecting facilities need to be provided

17. Graded Contour
● Small graded irrigation channels
● With uneven or warped surfaces
● Furrows are designed to fit the general curves of the
land
● Water application is the same as with graded straight
furrows
● Can be used on most soils except sandy soils and
others that crack easily

18. Advantages
● Best for safely irrigating steep land
● Can also be used with both large and small irrigation
systems
● High application efficiency
● Most of the same advantages as graded straight
furrows

19. Disadvantages
● Takes a lot of time to layout field
● Grassed waterways and structures are usually needed to carry
tailwater down the slope
● Large capacity furrows need to built and maintained through the
whole season
● Rodent control is necessary to avoid breakage and flow of water
from high to low streams

20. Corrugations
● Small, closely spaced channels
● Irrigate close-growing crops
● Conform to the slope of land because of the small
capacity of water channels
● Land slopes must be uniform to increase efficiency

21. Advantages
● Low costs for land preparation
● Best suited for areas of low rainfall
● Especially good for irrigating soils that tend to
bake or crust

22. Disadvantages
● Not essential to slopes of less than 1% or to
high rainfall areas due to erosion hazard
● Small flows of water

23. Land Preparation
● Uniform topography
● Divide fields into
design areas
● No sharp turns
● Rectangular
● Equal in length

24. Furrow Shape
● Heights of ridges vary between 15-40 cm
● Cross section
must be large
● Modified by the
water as it
moves along

25. Furrow Length
● Longer=more efficient
● Limitations on length:
o Intake rate of the soil
o Grade of the furrows
o Rainfall intensity
o Depth of application
o Field dimensions
o Location of soil boundaries
● Shouldn’t exceed 1,320 feet

26. Max Slopes for Various Soil Types
Soil Type
● Sand
● Sandy loam
● Fine sandy loam
● Clay
● Loam
*A min slope of ~0.05% required to ensure surface drainage
Maximum slopes*
● 0.25
● 0.40
● 0.50
● 2.50
● 6.25

27. Subsurface irrigation methods
 As suggested by the name, the application of water to fields in
this type of irrigation system is below the ground surface so that
it is supplied directly to the root zone of the plants.
 The main advantages of these types of irrigation is reduction of
evaporation losses and less hindrance to cultivation works which
takes place on the surface.
 There may be two ways by which irrigation water may be applied
below ground and these are termed as:
• Natural sub-surface irrigation method
• Artificial sub-surface irrigation method

28. Natural Sub-surface irrigation method
 Under favorable conditions of topography and soil conditions,
the water table may be close enough to the root zone of the
field of crops which gets its moisture due to the upward
capillary movement of water from the water table.
 The natural presence of the water table may not be able to
supply the requisite water throughout the crop growing season.
However, it may be done artificially by constructing deep
channels in the field which may be filled with water at all times
to ensure the presence of water table at a desired elevation
below the root zone depth.

29. Natural Sub-surface irrigation method
 Though this method of irrigation is excellent from both water
distribution and labour saving points of view.
 it is favorable mostly for the following
• The soil in the root zone should be quite permeable
• There should be an impermeable substratum below the water
table to prevent deep percolation of water.
• There must be abundant supply of quality water that is one
which is salt free, otherwise there are chances of upward
movement of these salts along with the moisture likely to
lead the conditions of salt incrustation on the surface.

30. Artificial subsurface irrigation method
 The concept of maintaining a suitable water table just below
the root zone is obtained by providing perforated pipes laid in a
network pattern below the soil surface at a desired depth.
 This method of irrigation will function only if the soil in the
root zone has high horizontal permeability to permit free lateral
movement of water and low vertical permeability to prevent
deep percolation of water.
 For uniform distribution of water percolating into the soil, the
pipes are required to be very closely spaced, say at about 0.5m.

31. Artificial subsurface irrigation method
 Further, in order to avoid interference with cultivation the pipes
have to be buried not less than about 0.4m below the ground
surface.
 This method of irrigation is not very popular because of the
high expenses involved, unsuitable distribution of subsurface
moisture in may cases, and possibility of clogging of the
perforation of the pipes.

32. Sprinkler Irrigation System
 Sprinkler irrigation is a method of applying water which is
similar to natural rainfall but spread uniformly over the land
surface just when needed and at a rate less than the infiltration
rate of the soil so as to avoid surface runoff from irrigation.
 This is achieved by distributing water through a system of
pipes usually by pumping which is then sprayed into the air
through sprinklers so that it breaks up into small water drops
which fall to the ground.

33. Sprinkler Irrigation System
 The system of irrigation is suitable for undulating lands, with
poor water availability, sandy or shallow soils, or where
uniform application of water is desired.
 No land leveling is required as with the surface irrigation
methods.
 Sprinklers are, however, not suitable for soils which easily
form a crust.
 The water that is pumped through the pump pipe sprinkler
system must be free of suspended sediments. As otherwise
there would be chances of blockage of the sprinkler nozzles.

34. Sprinkler Irrigation System
 In sprinkler irrigation, water is conveyed under pressure
through pipes to the area to be irrigated where it is passed out
through or sprinklers the system comprises four main parts
i. Power generator
ii. Pump
iii. Pipeline and
iv. Sprinkler

35. Sprinkler Irrigation System
 The power generator may be electrical or mechanical. A
centrifugal pump may be used for suction lift up to 37 to 50 cm.
 A piston type pump is preferable where water is very deep. The
pipe consists of two sections, the main line and the laterals.
 The main line may be permanently buried underground or may
be laid above ground, if it is to be used on a number of fields.
 The main pipes are usually made of steel or iron.

36. Sprinkler Irrigation System
 The laterals are lightweight aluminum pipes and are usually
portable.
 The sprinkler nozzles may be single or double, revolving or
stationery and mounted or riser pipes attached to riser.
 Each sprinkler head applies water to circular area whose
diameter depends up on the size of water, which varies from ¼ to
¾ inch per hour is determined by selecting the proper
combination of nozzles.

37. Sprinkler Irrigation System
Adaptations:
1) A dependable supply of water
2) Uneven topography
3) Shallow soils.
4) Close growing crops.

38. Sprinkler Irrigation System
Advantages:
1) It ensures uniform distribution of water
2) It is adaptable to most kinds of soil.
3) It offers no hindrance to the use of farm implements
4) Fertilizers material may be evenly applied through sprinklers.
This is done by drawing liquid fertilizer solution slowly in to the
pipes on the suction side of the pump so that the time of
application varies from 10 to 30 minutes.

39. Sprinkler Irrigation System
Advantages:
5) Water losses are reduced to a minimum extent
6) More land can be irrigated
7) Costly land leveling operations are not necessary and
8) The amount of water can be controlled to meet the needs of
young seedling or mature crops.

40. Sprinkler Irrigation System
 Disadvantage:
1) The initial cost is rather very high.
2) Any cost of power to provide pressure must be added to the
irrigation charges.
3) Wind interferes with the distribution pattern, reducing spread
or increasing application rate near lateral pipe.
4) There is often trouble from clogged nozzle or the failure of
sprinklers to revolve.

41. Sprinkler Irrigation System
 Disadvantage:
5) The cost of operations and maintaince is very high. Labour
requirement for moving a pipe and related work approximately
nearly one hour per irrigation.
6) It requires a dependable constant supply of water free slit and
suspended matter and
7) It is suitable for high value crops