1. 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

2. 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.

3. 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

4. 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

5. SITE ANALYSIS

6. 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
Temp (mm)
28.6
29.5
30.1
28.5
26.8
26.3
26.4
27.1
28.4
28.8
28.2
Rainfall, r (mm)
16.1
5.1
53.2
101. 7
21.7
12.1
6.8
4.1
7.7
22.6
101.6
64.6
417.3
Mean,Eo (mm)
205
201
227
210
214
211
209
225
235
192
173
2543
Et (mm)
137
134
151
140
143
141
139
150
157
161
128
115
1696
r-Et
-121
-129
-98
-38
-132
-146
-149
-138
-26
-50
-1277

7. valves INVENTORY G.I PIPES Pump PVC pipes PV array pump controller
wiring
discharge tubing or piping
valves
emitters
drip lines
solar panels
mounting racks

8. Design parameters LITERATURE REVIEW
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.

9. 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:
PV array
array mounting bracket and rack
pump controller
electrical ground for controller
wiring
discharge tubing or piping

10. 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
Control station (head control unit
Main and submain pipelines
Offtake hydrants
Hydrants
Manifold (feeder) pipelines
Dripper laterals
Emitters

11. 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

12. Weight of can & lid + Dry weight (g)
RESULTS AND ANALYSIS
Bulk density
QUADRANT
(CM)
Weight of can & lid + wet weight (g)
Weight of can & lid + Dry weight (g)
Weight of can +lid (g)
Mass of oven dried soil (g)
Bulk Density
(g/cm3) A
0-25
271.44
255.17
107.11
148.06
25-50
180.26
170.70
100.49
70.21 B
213.12
202.54
110.89
91.65
182.04
173.19
108.03
65.16 C
233.42
222.55
106.58
115.97
223.69
209.05
110.49
98.56 D
209.63
195.32
108.41
86.91
21.56
195.09
99.84
95.29

13. Results and analysis contd
Moisture Content
QUADRANT
(cm)
Mass of can
(g)
Weight of can + wet weight (g)
Weight of can + Dry weight
Moistur e content
Mass of
Dry soil
( g)
Moistur e
(%) A
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 B
24.91
102.54
96.57
5.97
71.66
8.33
22.58
106.57
99.77
6.8
77.19
8.81 C
23.32
99.42
92.53
6.89
69.21
9.96
16.44
95.62
88.94
6.68
72.5
9.21 D
25.17
144.37
134.00
10.37
108.83
9.53
25.03
110.01
102.27
7.74
77.24
10.02

14. Results and analysis contd
The net scheme irrigation obtained from CROPWATT 8.0 is 4.959mm/day
And the gross scheme irrigation is mm/day
Therefore Net Irrigation Requirement per crop
= (4.959/1000) x 5 x 2 x 0.3
= m3 or 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

15. 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

16. Results and analysis contd

17. Results and analysis contd
Supply line and main line
Δ H = (Q1.852) L
D4.871
Sub mains and laterals
Δ H = 5.35 (Q1.852) L

18. Results and analysis contd
Suction lift 4.5 m
Supply line m
Main line m
Sub main m
Laterals m
Sub Total
Fitting 10%
Difference in elevation m
Total
Power requirement = Q × H
360 × e
= ×
360 × 0.40
= Kw

19. DESIGN DRAWING

20. 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.

21. REFERENCE
ASAE 1990 ASAE EP 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 What you should know about mango growing. Kenya Farmer. Nairobi, Kenya: Agricultural Society of Kenya.
Griesbach J New mango types currently grown in Kenya.Kenya Farmer. Nairobi, Kenya: Agricultural Society of Kenya.

22. THANK YOU