DESIGN OF A SOLAR-POWERED DRIP
IRRIGATIOIN SYSTEM FOR GROWING
MANGOES IN BURA NANIGHI.
PRESENTER : TERER DUNCAN KIPKIRUI
F21/3964/2009
SUPERVISORS : DR. DUNCAN O MBUGE
Eng ORODI ODHIAMBO
INTRODUCTION
• Dry areas are often faced with critical soil moisture deficit
hence carrying out productive agriculture is increasingly
difficult.
• Percentage of land under irrigation in Kenya.
• Need for food security and increasing the amount of land
under agriculture in.
• The benefits associated with this project include improved
food productivity.
PROBLEM STATEMENT AND ANALYSIS
• Agricultural production in semiarid areas is largely constrained
by low rainfall, poor or low nutrient soils, high temperatures,
high solar radiation, and low precipitation.
• The ever-increasing population is also creating a strain on the
existing food sources and thus putting food security of the
area in jeopardy
• The area experience severe annual food deficits, due to the
use of traditional techniques of farming that produce crops
that hardly meet the subsistence requirements
OVERALL OBJECTIVE
To design a solar powered drip irrigation system for
growing mangoes
Specific
 To design a drip-irrigation system layout for a 30 hectare
piece of land
 To design and determine the system specifications which
comprises of the pump, the solar trackers and the amount of
flow required
SITE ANALYSIS
Site analysis contd
• Rainfall is highly variable and occurs in the March–May and
the November–December seasons.
• The area is mainly covered with open bush and rather dense
shrub vegetation.
Month
Jan
Feb
Mar
April May
June
July
Aug
Sept
Oct
Nov
Dec
Year
Mean
28.6
29.5
30.1
29.5
28.5
26.8
26.3
26.4
27.1
28.4
28.8
28.4
28.2
16.1
5.1
53.2
101.
21.7
12.1
6.8
4.1
7.7
22.6
101.6
64.6
417.3
Temp (mm)
Mean
7
Rainfall, r
(mm)
Mean,Eo
205
201
227
210
214
211
209
225
235
214
192
173
2543
Et (mm)
137
134
151
140
143
141
139
150
157
161
128
115
1696
r-Et
-121
-129
-98
-38
-121
-129
-132
-146
-149
-138
-26
-50
-1277
(mm)
INVENTORY
G.I PIPES
Pump
PVC pipes
PV array
pump controller
wiring
discharge tubing or piping
valves
emitters
drip lines
solar panels
mounting racks
LITERATURE REVIEW
Design parameters
• Area to be irrigated should be known .soil type identified,
type of crop to be planted, crop spacing and number of crops
per unit area should be put into consideration.
• Peak water requirement of crop per day should be known.
• Selection of emitter type, number of emitters per plant and
amount of water discharge per hour through each emitter
should be calculated.
• Layout of the system considering -topography, field shape and
location of the water source.
• Design of main and lateral drip lines. This depends upon
friction head losses.
• Selection of filters and other equipment that will be used in
the system.
Literature review contd
Cultivation of mangoes
• Climatic requirements
– Temperature ( 5- 45)
– Humidity and rainfall (average 105 mm)
Solar Water Pumping Principles
• Solar pumping system, the capacity to pump water is a function of
three main variables: pressure, flow, and power to the pump.
A solar-powered pumping system has the following minimum
components:
a) PV array
b) array mounting bracket and rack
c) pump controller
d) electrical ground for controller
e) wiring
f) discharge tubing or piping
Literature review contd
Solar power comes from photovoltaic (PV) cells that convert the
sun’s energy into usable DC electricity. A module consists of PV
cells and an array consists of several modules.
Drip irrigation system components
1. Control station (head control unit
2. Main and submain pipelines
3. Offtake hydrants
4. Hydrants
5. Manifold (feeder) pipelines
6. Dripper laterals
7. Emitters
PRODUCT DESIGN
METHODOLOGY
• Desk Study
– included the study of area map and the general information
about the area.
• Field Method
– Land divided into four quadrants.
Water quality test
pH
Turbidity, N.T.U
Dissolved solids, mg/l
Suspended solids, , mg/l
RESULTS AND ANALYSIS
• Bulk density
QUADRANT
(CM)
Weight of
Weight of
Weight of Mass
can & lid +
can & lid
can
+ Dry
(g)
wet
A
B
C
D
of
+lid oven
dried soil
Bulk
Density
(g/cm3)
weight (g)
weight (g)
(g)
0-25
271.44
255.17
107.11
148.06
1.508127
25-50
180.26
170.70
100.49
70.21
0.715153
0-25
213.12
202.54
110.89
91.65
0.933539
25-50
182.04
173.19
108.03
65.16
0.663714
0-25
233.42
222.55
106.58
115.97
1.181260
25-50
223.69
209.05
110.49
98.56
1.003923
0-25
209.63
195.32
108.41
86.91
0.88525
25-50
21.56
195.09
99.84
95.29
0.970616
Results and analysis contd
Moisture Content
QUADRANT
(cm)
Mass
Weight
of can
of can of can + e
(g)
+
wet Dry
weight
(g)
A
B
C
D
Weight
weight
Moistur
Mass of
Dry soil
content
( g)
Moistur
e
(%)
(g)
(g)
0-25
23.79
106.22
98.42
7.8
74
10.54
25-50
32.16
81.99
77.73
4.26
45.57
9.35
0-25
24.91
102.54
96.57
5.97
71.66
8.33
25-50
22.58
106.57
99.77
6.8
77.19
8.81
0-25
23.32
99.42
92.53
6.89
69.21
9.96
25-50
16.44
95.62
88.94
6.68
72.5
9.21
0-25
25.17
144.37
134.00
10.37
108.83
9.53
25-50
25.03
110.01
102.27
7.74
77.24
10.02
Results and analysis contd
• The net scheme irrigation obtained from CROPWATT 8.0 is
4.959mm/day
• And the gross scheme irrigation is 5.742mm/day
• Therefore Net Irrigation Requirement per crop
= (4.959/1000) x 5 x 2 x 0.3
= 0.014877m3 or 14.877 l/crop/day
• Area of wetted soil = Sp x Sr x Pw
Where Sp = distance between the plant within a row
Sr = distance between plant rows or row spacing
(m)
• Area of wetted soil = 5 x 2 x 0.6
= 6 m2
Results and analysis contd
• Available soil moisture per crop= 140mm/m
= (140/1000) x 0.6 =
= 0.084m3 or 84 l/crop
• Readily available moisture for drip system to be
replenished by irrigation
= 84 l/crop x 0.2
= 16.8 l/crop
Results and analysis contd
Results and analysis contd
• Supply line and main line
• Δ H = 15.27 (Q1.852) L
D4.871
• Sub mains and laterals
• Δ H = 5.35 (Q1.852) L
D4.871
Results and analysis contd
•
•
•
•
•
•
•
•
•
Suction lift
Supply line
Main line
Sub main
Laterals
Sub Total
Fitting 10%
Difference in elevation
Total
4.5 m
1.14 m
2.58 m
2.9814 m
4.776 m
15.9774
1.59774
6.5 m
24.07514
Power requirement = Q × H
360 × e
= 19.36476 × 24.07514
360 × 0.40
= 3.237 Kw
DESIGN DRAWING
CONCLUSION AND RECOMENDATION
• The broad objectives of carrying out a survey of the area to
determine its topographical characteristics was achieved
which guided in the irrigation system layout.
• The irrigation system layout should be checked regularly to
avoid clogging of pipes and emitters and the necessary repairs
and maintenance should be carried out.
REFERENCE
• ASAE 1990 ASAE EP 405.1.Design and installation of micro-irrigation
systems.
• FAO 1985 Water quality for agriculture.Fao Irrigation and Drainage
Paper No 29,Rev.1.preparedby:Ayers,R.S&westcot DW Rome,Italy.
• Food and Agriculture Organization of the United Nations (2008) The
State of Food Insecurity in the World 2008: High food prices and
food security—threats and opportunities.
• Griesbach J. 1981. What you should know about mango growing.
Kenya Farmer. Nairobi, Kenya: Agricultural Society of Kenya.
• Griesbach J. 1985. New mango types currently grown in
Kenya.Kenya Farmer. Nairobi, Kenya: Agricultural Society of Kenya.
• http://www.ehow.com/list_7505003_hydrology-soiltypes.html#ixzz2kqjmm44f
• http://www.thecommunityengineer.com/forum.html.
• THANK YOU