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 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

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

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.

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

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

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

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 1.508127 25-50 180.26 170.70 100.49 70.21 0.715153 B 213.12 202.54 110.89 91.65 0.933539 182.04 173.19 108.03 65.16 0.663714 C 233.42 222.55 106.58 115.97 1.181260 223.69 209.05 110.49 98.56 1.003923 D 209.63 195.32 108.41 86.91 0.88525 21.56 195.09 99.84 95.29 0.970616

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

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

Results and analysis contd Suction lift 4.5 m Supply line 1.14 m Main line 2.58 m Sub main 2.9814 m Laterals 4.776 m Sub Total 15.9774 Fitting 10% 1.59774 Difference in elevation 6.5 m Total 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-soil-types.html#ixzz2kqjmm44f http://www.thecommunityengineer.com/forum.html.

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