الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Agriculture is one of the most important national economic sectors. It contributed to the gross domestic product by 11.5 % with Current prices by product at factor cost according to economic activities in year 2021/2022 Water is one of the most important inputs to the economic development for countries The less of the water resources and more of the water demands are the most severe problem in the world. this is the case in Egypt. Egypt is facing the less water resources challenges by applying policies to improve the performance of the water resources system.
Surface irrigation is the most widely irrigation methods in Egypt especially in old valley and Delta. Ahigh percentage of the irrigation water can lost through run off, deep percolation and evaporation one prime problems, also improves management and inadequate equipment. It caused deficiency of surface irrigation.
Controlled surface irrigation systems by using enclosed pipelines have successfully demonstrated in recent years, gated pipe or perforated pipe system has been considered one of the most important obligatory irrigation systems that saves irrigation water lost by deep percolation and run off and increased yield.
The perforated or gated pipe system having disadvantages.
- outflow from outlet having angle started from the first outlet near the pumping unit resource about 45o and greater until reached to about 90o at the end of the gated or perforated pipe system.
- do not claim to irrigate any crops at different furrow spacing.
- increases soil erosion beneath the outlets of both systems.
Therefore, the modified perforated pipe (trailing perforated pipes) system eliminates all the disadvantages of both perforated pipe system and gated pipe system.
Accordingly, a new idea has worked to consume water and solve previous problems through modified perforated pipe system (trailing perforated pipe) using long plastic hose attached with outlets along the perforated pipe system. Hence the suggested technique will play an important role in improving the perforated pipe system and improving surface irrigation system.
The main objective of the field experimental work was to study the effect of using modified perforated irrigation (trailing perforated pipe) system (T2) on the total water applied, water irrigation saving, water application efficiency, water distribution efficiency, water use efficiency and corn crop production. under prevailing condition in Egyptian old valley and also, its effects on advance and recession time comparing with traditional irrigation system (T1)
To achieve these objectives the following work carried out:
1. Theoretical prediction of the modified perforated (trailing perforated) pipe irrigation performance to estimate the expected suitable outlets diameter along the system.
2. Laboratory work conducted in the hydraulic laboratory test at the department of the field irrigation and drainage engineering of the Agricultural Engineering, Research Institute(AERI)- Agricultural Research Center(ARC) .to find out the relation between the outlet discharge coefficient(Cd) and the length of the plastic hose to choose the most suitable length of the plastic hose which attached with outlet along the modified perforated pipe (trailing perforated pipe ) system giving the highest water uniformity distribution .
- Designing and locally manufacturing of the modified perforated pipe (trailing perforated) system.
-Measuring the actual performance of the modified perforated piping system
-Verify the variation of the theoretical consideration of trailing perforated pipe irrigation performance and experimentally measured results of the actual trailing perforated pipe irrigation performance to the experimentally obtained data.
3. Field experimental work conducted during growing season 2021/2022 on corn crop (Corn yellow mono hybrid 2088) at private farm on Kafr Taha –Shepin Elqanater- Lower Egypt- El-Qalupia Governorate, old valley in Egypt. to studying the effect of the modified perforated irrigation system modified perforated pipe) (T2), under laser land leveling technique at 0.10% slope under different furrow lengths (75 (L75), 100 (L100) and 125m (L125)) comparing with traditional irrigation system (T1) under the same treatment of furrows lengths and manually traditional land leveling technique at slope 0.1%.
The results of the laboratory experimental work showed that:
The outlets’ diameters along the system ranged from 23.6 mm to the 24.3 mm. Therefore, the system was manufactured using UPVC pipe had 160 mm outside diameter. The outlets were located at approximately 0.75 m spacing (the same spacing between furrows) and modified the circular outlets to 25 mm in diameter attach with a saddle and plastic hose having length about 0.5-2.0 meter.
The measured resultant pressure head (Hcom) increased gradually until it reached pipe end, and its value was about 107.3 % of the original pressure head at system inlet.
The actual measured pressure head along the modified perforated pipe irrigation system represents the effect of the system length on the pressure head variation along the system was about (10%).
The measured outlet discharges increased gradually until it reached at system end and its values was about 109.0 % of the measured outlet discharge rate at the system inlet. the flow variation through the system was about 8.3%. Therefore, the water uniformity distributions along system were about 91.7 %.
The increasing length of hose attached with a circular outlet through a saddle can be recommended as pressure head increased.
There were always narrow range trends in the performance results and very close values between the experimentally measured and theoretically predicted results.
The results of the field experimental test showed that:
the average values of water advance time, water recession time and opportunity time increased in case of traditional irrigation methods compared with modified perforated pipe using the modified perforated pipe (trailing perforated pipe) system in three cases furrow lengths, saving irrigation water by 45.0 % per feddan in average.
The maximum value of water application efficiency was achieved for both traditional irrigation method and irrigation with modified perforated pipe in case of treatment L75.
the average values of the water distribution efficiency (WDE) for both traditional irrigation method and the modified perforated irrigation pipe decreased as furrows lengths increased.
The maximum value of water use efficiency was achieved in the case of treatment L75 for irrigation with modified perforated pipes irrigation system. Also, the results revealed that irrigation with modified perforated pipes irrigation system technique improved yield water use efficiency for corn yield under three treatments of furrows lengths comparable to traditional irrigation system.
As a general recommendation, using modified perforated pipes irrigation system (trailing perforated pipes) modified the circular outlets to 25 mm in diameter attach with a saddle and plastic hose having length about 0.5-2.0 meter long with laser land leveling technique at 0.10 slope and the furrows lengths of 75 m.