ABSTRACT
This dissertation is a study to evaluate and compare the
hydraulic performance of plastic and iron mini sprinkler system using 8mm and
14mm diameter nozzle sizes.
The study was carried out at a farm land of the national
water resources institute, Mando, Kaduna.
In this study, meteorological data such as rainfall,
evaporation, relative humidity, wind speed/ direction, maximum and minimum
temperature were first taken into consideration, soil, sample test were
investigated for their physical and chemical properties.
Water is a key factor in increasing agricultural production.
However, the global Climate Change and its attendant effects on scarce water
resources have further reduced the amount of water available for agriculture.
The need to encourage small scale farmers on the use of modern method such as
sprinklers other than the traditional mass irrigation methods which waste
water. At least, the stemming problems of neighbor irrigators sharing same
water source will be arrested.
The work is based on the evaluation of the hydraulic
performance of the plastic and iron sprinkler system towards the determination
of the discharges of the sprinkles, Pressure radius of throw of the mini
sprinklers, application rate, distribution pattern of the sprinklers on the
soil, and the uniformity coefficient of the sprinkler system.
The experimental set up for determination of the hydraulic
performance consist of a horse power (1hp) pump connected to a 200L reservoir
tank filled to the brim with water. A pressured hose connected to the
reservoir, takes water through the inlets to the pump. A pipe connected to the
out let of the pump, take the water to the main line passing through a filter
to entrap solid particles. The mainline, distribute the water to the sub main
line, and the sub main line, takes water to the lateral line, hosting the
sprinklers. The water gets to the riser pipe, and the sprinklers rotate and
spread water.
All measurements for the parameters were set up for 9
different operating pressure with an increment of 0.5kg/cm2, the
results were collected and evaluated for their hydraulic efficiencies.
Maximum and minimum pressures were obtained as
8.9,11.1L/Min and 40.0 -52.6 L/Min for plastic and iron. The radius of throw
were obtained as 2.0, 2.4cm and 8.2,14.5cm respectively. For
plastic and iron made sprinkler system. The sprinkler application rate
(precipitation rate) were obtained at min and max to be213.5mm/hr,814.2mm/hr
for 8mm iron and 692.3mm/hr,1172.3mm/hr for 8mm plastic. The distribution
pattern of the system on the soil is uniform, with the system uniformity
coefficient found to be 96.7%,97.2% 14mm plastic and iron. 96.99%,97.9%8mm
plastic and iron respectively.
CHAPTER ONE
INTRODUCTION
1.1 Background of
the Study
In many part of the world, rainfall is not uniformly
distributed over time and space. In addition, the amount of rain is not
adequate to meet the water requirement of crops and to supplement this
deficiency, artificial application of water is required.
Irrigation is the application of water to soil to assist in
the production of crops. It is practiced in many parts of the world with the
aims of providing water for crop growth when natural precipitation is in short
supply and /or distribution is erratic. Irrigation is usually supplied to
supplement the water available from rainfall, soil moisture, and capillary rise
of groundwater.
Irrigation water is brought to dry land through artificial
means, such as pipes, hoses, or ditches. The land that is being irrigated
usually contains crops,grass, or vegetation that would not usually receive
enough water from rainfall or other natural sources. Sometime,the reason to
irrigate a portion of land is that it happens to be a dry season, with less
than average amounts of rainfall. Or, it might be necessary to do so because
theland never would receive enough water on its own to be fertile. The water
that is used for irrigation might be taken from nearby lakes, reservoirs,
rivers or wells. The source of irrigation water can be surface water, ground
water or non-conventional water (such as desalinated water and treated
wastewater)Sawa and Frenken, 2002.
The amount of water that is to be used for irrigation depends
on the type of crop that is being farmed as well as the amount of rainfall in
the region. The US for instance uses about
one third of the water utilized every year (US Geological
Survey, 2014).Moreso, the correct amount of water to apply at each irrigation
depends on the water holding capacity of the soil and root depth, infiltration
rate, and the rate at which water goes into the soil which varies from one
irrigation to the next and from season to season.
Water must be available in sufficient quantity from a locally
accessible source. A clean supply of water free of sediment is required to
avoid blockage in sprinkler nozzles and crop spoilage (FAO, 1988).
There are many methods that can be used for irrigating
farmland, and each one needs an experienced farmer to know exactly how much
water to use and when to use it. Some of the methods includes furrow, Basin,
Border, Drip and Sprinkler. However, sprinkler irrigation is a method of
applying irrigation water which is distributed through a system of pipes
usually by pumping. It is then sprayed into air through sprinklers so that it
breaks up into small water drops which falls to the ground. The pump supply
system, sprinklers and operating conditions must be designed to enable uniform
application of water.
Sprinkler Irrigation is suited for most row, field and tree
crops and water can be sprayed over or under the crop canopy. However, large sprinklers
are not recommended for irrigation of delicate crops such as lettuce because
the large water drops produced by the sprinkler may damage the crop.
Sprinkler Irrigation is adapted to any farmable slope,
whether uniform or undulating. The lateral pipes supplying water to the
sprinkler should always be laid out along the land contour whenever possible.
This will minimize the pressure changes at the sprinklers and provide a uniform
irrigation.
Sprinklers are suited with high infiltration rates. Although
they are adaptable to most soil types. The average application rate of the
sprinkler (mm/hour) is set to lower than basic infiltration rate of the soil so
that surface pounding and run off can be avoided. Sprinklers are not suitable
for soil that easily form a crust or in case of risk of salinization. Moreover,
they can easily clog with the presence of sediments or debris. If sprinkler
irrigation is the only method available, then light fine sprays should be used.
Sprinkler producing large water droplets should be avoided (FAO, 1991).
A good clean supply of water, free of suspended sediments is
required to avoid problems of sprinkler nozzle blockage and spoiling the crop
by coating it with sediments. A sprinkler requires water flow and water
pressure to operate. When a sprinkler design fails, it is almost always due to
a lack of water pressure at the sprinkler.
The water pressure of a sprinkler irrigation system is the
energy that makes the water to flow. And as the water flow from the water
source through an assembled system of pipes, only a small amount of water
pressure is used up. So after the water gets through all the pipes and valves
and reaches the sprinkler, there still must be enough pressure left to make the
sprinkler head rotates correctly. So by using the correct sizes of pipes /
hoses, etc. one can control how much pressure is lost in the irrigation system.
1.2 Statement of
the Research Problem
Water is a key factor in increasing agricultural production.
However, the global Climate Change and its attendant effects on scarce water
resources have further reduced the amount of water available for agriculture.
More so, irrigation of plant is usually time consuming
activity most especially for furrow, basin and border to be done in a
reasonable amount of time, it requires a large amount of human resources and
efforts.
All the steps were executed by humans with close monitoring
by farmers to control water from overflowing its banks. Traditionally, mass
irrigation remains one method used by small scale farmers to water their
plants. This method only represents massive losses since the amount of water
given is always in excess of the plants need. The excess water is evacuated by
the holes of the pots in green house or it percolate through the soil in field.
Perhaps, the contemporary perception of a small scale farmer towards irrigation
water is free, renewable sources that can be used in abundance. However, this
is not realistic as statistics have shown that the volume of accessible water
surface is on the decrease. According to the UN Water‟s 2011 policy brief, it
was forecast that by 2025, 1.8 billion people will experience absolute water
scarcity, and two third of the world will be living under water-stressed conditions.
(UN Water‟s 2011 brief)
It is therefore reasonable to assume that it will become very
expensive resources everywhere. It has become imperative to begin plan to
economies water use for optimum productivity. This is possible only through
improved water management and adopting advanced techniques of irrigation. One
such method of modern irrigation is sprinkler irrigation system which can
become more popular among farmer in the country if encouraged.
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Item Type: Project Material | Size: 89 pages | Chapters: 1-5
Format: MS Word | Delivery: Within 30Mins.
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