1 DESIGN OF A SOLAR-POWERED DRIP IRRIGATIOIN SYSTEM FOR GROWING MANGOES IN BURA NANIGHI. PRESENTER : TERER DUNCAN KIPKIRUIF21/3964/2009SUPERVISORS : DR. DUNCAN O MBUGEEng ORODI ODHIAMBO
2 INTRODUCTIONDry 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 jeopardyThe 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 SpecificTo design a drip-irrigation system layout for a 30 hectare piece of landTo design and determine the system specifications which comprises of the pump, the solar trackers and the amount of flow required
6 Site analysis contdRainfall 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.MonthJanFebMarAprilMayJuneJulyAugSeptOctNovDecYearMeanTemp (mm)28.629.530.128.526.826.326.427.128.428.828.2Rainfall, r (mm)188.8.131.521. 721.7184.108.40.206.722.6101.664.6417.3Mean,Eo (mm)2052012272102142112092252351921732543Et (mm)1371341511401431411391501571611281151696r-Et-121-129-98-38-132-146-149-138-26-50-1277
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 mangoesClimatic requirementsTemperature ( 5- 45)Humidity and rainfall (average 105 mm)Solar Water Pumping PrinciplesSolar 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 arrayarray mounting bracket and rackpump controllerelectrical ground for controllerwiringdischarge 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 componentsControl station (head control unitMain and submain pipelinesOfftake hydrantsHydrantsManifold (feeder) pipelinesDripper lateralsEmitters
11 PRODUCT DESIGN METHODOLOGY Desk Study included the study of area map and the general information about the area.Field MethodLand divided into four quadrants.Water quality testpHTurbidity, N.T.UDissolved solids, mg/lSuspended solids, , mg/l
12 Weight of can & lid + Dry weight (g) RESULTS AND ANALYSISBulk densityQUADRANT(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)A0-25271.44255.17107.11148.0625-50180.26170.70100.4970.21B213.12202.54110.8991.65182.04173.19108.0365.16C233.42222.55106.58115.97223.69209.05110.4998.56D209.63195.32108.4186.9121.56195.0999.8495.29
13 Results and analysis contd Moisture ContentQUADRANT(cm)Mass of can(g)Weight of can + wet weight (g)Weight of can + Dry weightMoistur e contentMass ofDry soil( g)Moistur e(%)A0-2523.79106.2298.427.87410.5425-5032.1681.9977.734.2645.579.35B24.91102.5496.575.9771.668.3322.58106.5799.776.877.198.81C23.3299.4292.536.8969.219.9616.4495.6288.946.6872.59.21D25.17144.37134.0010.37108.839.5325.03110.01102.277.7477.2410.02
14 Results and analysis contd The net scheme irrigation obtained from CROPWATT 8.0 is 4.959mm/dayAnd the gross scheme irrigation is mm/dayTherefore Net Irrigation Requirement per crop= (4.959/1000) x 5 x 2 x 0.3= m3 or l/crop/dayArea of wetted soil = Sp x Sr x PwWhere Sp = distance between the plant within a rowSr = 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/cropReadily available moisture for drip system to be replenished by irrigation= 84 l/crop x 0.2= 16.8 l/crop
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 REFERENCEASAE 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.