Title: CHAPTER IV IRRIGATION SYSTEM
1CHAPTER IVIRRIGATION SYSTEM
2The art of irrigation is very ancient and has
been essential for the development and blossoming
of some civilizations.
3- INTRODUCTION
- The art of irrigation is very ancient and has
been essential for the development and blossom of
some civilizations. - II Kings 3l6-l7 of the Holy Bible alludes to the
irrigation, in 2000 B.C. In the same year, queen
of Assyria detoured the Nile River to irrigate
the Egyptian desert. - Irrigation is also mentioned in the old documents
of Syria, Persia, India, China, Java and Italy.
4- INTRODUCTION
- The importance of the irrigation in our times has
been defined accurately by N.D Gulati - In many countries the irrigation is an old art,
as much as the civilization, but for the humanity
it is a science, the one to survive.
5- OBJECTIVES
- To provide the necessary moisture for the crop
development. - To ensure sufficient supply of water during
droughts of short duration and unpredictable
climate.
6OBJECTIVES
- To dissolve soil salts.
- It is a way to apply agrochemicals.
- To improve the ambient conditions for the
vegetative growth. - To activate certain chemical agents.
- To generate operational benefits.
7The hydrologic cycle.
8IRRIGATION METHODS
- Flood
- Furrow
- Infiltration
- Subsurface
- Sprinkler Overhead.
- Drip/Micro
- Hydroponics
9Selecting the Irrigation Method
- Crop Type
- Soil
- Water supply
- Climatologic conditions
- Availability and reliability of energy
- Available technology
- Economical and social considerations
10CAPACITIES AND LIMITTATIONS 1. Crop, soil
and topography. 2. Quantity and quality of
water. 3. Crop yields.
11CONSIDERATIONS OF MANUAL LABOR AND
ENERGY 1. Surface irrigation. 2. Sprinkler
irrigation. 3. Drip irrigation.
12Conditions for the selection of an irrigation
method
13Comparison of irrigation methods
14- SURFACE IRRIGATION
- The water runs on the soil surface providing
necessary moisture to the plants for its
development.
15SURFACE IRRIGATION
- The basic components are
- Water source
- Supply Lines
- Control mechanism
- Dams or dikes of control
- Furrows of irrigation
- Drainage system
- Reuse of irrigation water
16Surface Irrigation
Gated pipe irrigation system
17STRIP BORDER IRRIGATION
- The water is applied to a leveled area surrounded
by ridges. - Each irrigated area is completely at level
without slopes in any direction. - It is not necessary that the edges are not
rectangular or straight nor that the ridges are
permanent. - This technique is called leveled flood or
irrigation by strip borders. -
18FLOOD IRRIGATION
- It is a traditional system and is more commonly
used in agriculture. One adapts to extensive
planting methods. It is prone to diseases that
are developed due to excess of soil moisture. - It uses surface (rivers, lakes, pools, etc.)
water resource or a deep well. - This method requires that the fields are prepared
with gentle slopes so that the water runs slowly
by gravity and arrives at the lowest part of the
farm, where it is collected by open channels for
elimination or is recycled for use. -
19STRIP IRRIGATION WITH DIKES
- The flood irrigation is most popular.
- It is used mainly in narrow row crops like rice.
- It can be defined as the application of water
between parallel strips. - The strip between adjacent dikes does not have
slope in the transverse direction, but these have
slopes in the direction of the irrigation. -
-
20Figure 2(a) Periodic flood Irrigation
21Figure 2(b) Permanent flood Irrigation
22Figure 2(b) Simple flood Irrigation
23Figure 2(c) Multiple flood Irrigation
24Figure 2(d) Flood irrigation for crop in
terraces
25Figure 3(a) Simple ditches
26Figure 3(b) Double ditches
27FURROW IRRIGATION OR IRRIGATION BY
INFILTRATION
- The furrows are channels with slopes that are
formed from the soil. - It is designed so that the water runs throughout
the desired field. - The water under pressure arrives at the highest
elevation of the field. It is distributed by
channels or tubes, towards the fields where it
will enter the furrows to flood the area. -
-
28FURROW IRRIGATION OR IRRIGATION BY
INFILTRATION
- From the supply lines, the water enters the
furrows by means of floodgates, siphons or by
opening a furrow. - Water is applied when the channel is opened. One
may use flood gates to control the application of
water to a particular field.
29Figure 4(a) Simple furrows
30Figure 4(b) Multiple furrows
31Figure 4(c) Snail type furrows
32Figure 5(a) Circular sink furrows
33Figure 5(b) Square sink furrows
34Figure 6 Irrigation by surface infiltration
35 FURROWS ALONG THE CONTOUR LINES 1. It
consists of small channels with continuous slope
and almost uniform by which the hilly areas are
irrigated. The furrows follow the contours lines
of the land. 2.This system can be used in uneven
lands, hilly areas, row crops and except for
sandy soils..
36LEVELED FURROWS
- The leveled furrows with no slopes are formed by
a furrow opener and are used to irrigate crops
seeded on the furrows or on the sides of furrows.
- This method requires a fast supply of water.
- The leveled furrows adapt better to soils with a
moderate to slow index absorption and an index of
retention capacity from medium to high. With the
furrow irrigation, the best results are obtained
in gentle and uniform slopes.
37FURROWS ON SLOPES
- These furrows consist of small channels with an
uniform continuous slope in the direction of the
irrigation. - This method can be used for the row crops,
including vegetables. - The furrows with slopes can be used in all soils
except sandy soils, with high degree of
infiltration capacity and with a very little
lateral distribution. - This method must be used with extreme care in
soils with high concentration of soluble salts. -
38CORRUGATED FURROWS
- The system consists of a partial wrinkling of the
soil surface. - The irrigation water does not cover all the land,
but is distributed in small channels or
undulations at regular spaces. - The water applied in the undulations infiltrates
into the soil and extends laterally to irrigate
the intermediate spaces between the furrows. - The irrigation by undulations or corrugations
adapts better to the drought areas and flat lands
with slopes of l to 8.
39SPRINKLER IRRIGATION 1.The water is applied on
the soil surface in form of a rainfall. 2.The
spray pattern is obtained when the water at
pressure is expelled through small orifices.
3.The operating pressure is developed by an
appropriate pumping unit.
40TYPES OF SPRINKLER IRRIGATION SYSTEMS
- Manual operated and portable system.
- Lateral system on wheel (movable).
- Traveling sprinkler system with progressive
movements. - Central pivot system.
- Linear movement system.
- Low energy pressure system.
- Solid-set system.
41MANUALLY OPERATED AND PORTABLE SYSTEMS
- Include lateral pipe with sprinklers installed at
regular intervals. - The risers are connected to the lateral tube. The
length of the tube is selected to correspond with
the desired spacing of the sprinklers.
42MANUALLY OPERATED AND PORTABLE SYSTEMS
- The lateral pipe with sprinklers is placed on a
ground surface. It is used until the application
has been terminated. - Then, the lateral tube is dismantled and is
positioned in the next section. - This system has a low initial cost, but requires
high manual labor. It can be used in almost all
the crops. However it is difficult to move the
lateral pipes, when the crop is mature.
43LATERAL SYSTEM ON WHEELS (MOVABLE)
- This system is a variation of the manual system.
- The lateral pipe is mounted on wheels.
44LATERAL SYSTEM ON WHEELS (MOVABLE)
- The height of the wheels is chosen so that the
axis exceeds height of the crop for easy
movement. - A drive unit is commonly a motor driven with
gasoline and is located near the center of the
lateral pipe.
45- TRAVELING SPRINKLER SYSTEM WITH PROGRESSIVE
MOVEMENTS - This system uses a spray (tube) gun of high
pressure and high volume. - The spray gun is mounted on a tow.
- The water is supplied by means of a flexible hose
or from an open ditch.
46CENTER PIVOT SYSTEM
- It consists of a lateral pipe with simple
sprinkler supported by a series of towers. - The towers car is impelled in such way so that
the lateral pipe moves around the center about
the pivot point.
47LINEAR MOVEMENT SYSTEM
- The linear movement system is similar to the
central pivot. - The line of the pipe extends in perpendicular
direction to the lateral one. - The delivery of the water to the lateral is by a
flexible hose or from an open ditch.
48- LOW ENERGY PRESSURE SYSTEM (LEPA)
- LEPA systems are similar to the linear movement
systems of irrigation. - The orifice in the lateral pipe and pipes can
discharge at very low water pressure, exactly
according to the soil moisture.
49SOLID-SET SYSTEM
- Here, the sufficient lateral pipes are placed in
the field and are not moved during the season. - The system of solid set is portable, with network
of aluminum tubes for the irrigation. - Enough lateral lines are used to cover all the
area. - The system reduces to a minimum the need of
manual labor during the irrigation season.
50TYPES OF SPRINKLERS
- Rotating sprinkler, impact type These are more
commonly used for wide variation of pressure,
discharge, spacing and rate of application for
different crops.
51TYPES OF SPRINKLERS
- Sprinkler type These are rotating sprinklers
with a discharge up to 60 m3/h at a pressure head
of 60 meters. It can cover areas up to one
hectare simultaneously.
52TYPES OF SPRINKLERS
- Sprinklers with low flow rate These sprinklers
apply l20 to 350 liters per hour at a pressure
head of l5 to 25 meters. These are used mainly in
irrigation of fruit or chards.
53TYPES OF SPRINKLERS
- Mini sprinklers These can apply 30 to l20 liters
per hour at a pressure head of l5 to 25 meters.
These are used in vegetables and nurseries.
54SUBSURFACE IRRIGATION
- In many areas, soil conditions and topography are
favorable to the water below the ground surface. - The favorable conditions are
- The existence of impermeable subsoil at a depth gt
1.8 meters. - Silt or silt-sandy permeable layer.
- Uniform topography and moderate slopes.
55- SUBSURFACE IRRIGATION
- ADAPTABILITY
- It is appropriate for uniformly textured soils
with a good permeability so that the water is
mobilized quickly, in a horizontal and vertically
direction and to a recommendable depth under the
root zone.
56- SUBSURFACE IRRIGATION CHARACTERISTICS
- This method is used in soils with low capacity.
- When the surface irrigation cannot be used and
the cost of pressure irrigation system is
excessive.
57- SUBSURFACE IRRIGATION
- LIMITATIONS
- The water with high concentration of salts can
not be used. In some arid regions, the soils can
be salty. - The selection of crops is limited.
- The crops with deep root system (such as some
citric) are not generally suitable for subsurface
irrigation.
58- NATURAL SUBSURFACE IRRIGATION
- Geological and topographical conditions are
favorable. - It is adaptable for almost flat levels with deep
surface layer and high lateral permeability. - At a depth of 2 to 7 meters from the soil
surface, there is usually an impermeable rocky
substratum.
59- DRIP IRRIGATION
- The application of water is by means of drippers
of that are located at desired spacing on a
lateral line. - The emitted water moves due to a unsaturated
soil.
60SUBSURFACE DRIP IRRIGATION (SDI)
- In this system, laterals with drippers are buried
at about 45 cm depth. - The purpose is to avoid the costs of
transportation, installation and dismantling of
the system at the end of a crop. - When it is located permanently, it does not harm
the crop and solve the problem of installation
and annual or periodic movement of the laterals. - A carefully installed system, it can last for
about 10 years.
61XYLEM IRRIGATION
- Xylem irrigation is the direct application of the
water with necessary chemical agents into xylem
of the trunk of a tree using a series of
injectors depending on the age of the tree. - Xylem irrigation is also called ultra micro,
high frequency, tension, tree injection, or
irrigation of chemotherapy. - There is no difference in the concept that these
names represent. - The basic idea originated when several chemical
products were injected within the vascular system
of the plant.
62HYDROPONICS SYSTEM
- The growth of plants without soil is known as
hydroponics. - During l925-l935, an extensive work was done to
modify the nutrient culture in the nurseries. In
l930, W.F Gericke at University of California,
defined hydroponics as a science to cultivate
plants without the soil use, but using inert
materials such as Sand, sawdust, among others. - A nutrient solution with all the essential
elements is added for a good development of the
plants.
63SUMMARY
- The additional food need for the world population
impose the fast development of the irrigated land
throughout the world.
64SUMMARY
- Although, it is of vital importance for the arid
regions, it is also necessary in the humid
regions. In many regions of the world it is
possible to irrigate with the water that is
available.
65SUMMARY
- Less than half of the applied water is beneficial
to the crop. That irrigation water is lost
generally to the soil by erosion, deep
percolation, alkali accumulation, and leaching.
66Figure 12 General components of a
hydroponics system
67new irrigation systems are being developed
to obtain the high efficiency of water
application