الفهرس 
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Abstract
Field experiments were carried out during agricultural season of 2018-2019 at Wadi EL-Natroun Station (30° 13’ E longitude and 30° 25’ N latitude), Water Management Research Institute, El-Behera Governorate, Egypt to study the effect of using the drainage of aquaculture as nontraditional source of water compared to well water under surface and subsurface drip irrigation systems on the yield of sesame and onion crops. Field experiments were carried out under conditions of two drip irrigation systems (surface and subsurface), two water resources (well water and aquaculture drainage), four operating pressures (1.0, 1.2, 1.4 and 1.6 bar), two filter types (screen and sand filters) and combination of them, two different crops (sesame and onion) and three nitrogen fertilizer rates (20, 60 and 100% N). The performance evaluation of drip irrigation systems was conducted in terms of hydraulic characteristics (emitter discharge rate, application efficiency, emitters clogging and emission uniformity), amount of applied water, water use efficiency, nitrogen use efficiency, yield and its components added to economic analysis (production cost, total return, net return and water productivity). The obtained experimental results reveal that 1- Utilizing aquaculture drainage enhances water and fertilizer-use efficiency, added to crop yield compared to well water. 2- Drip irrigation system under pressure of 1.4 bar provides the suitable condition for operating. 3-Screen-sand combined filters can be used for aquaculture drainage filtration, while screen filter can be used for well water to obtain minimum emitter clogging. 4-Surface irrigation system gives greater results of application efficiency, emitter clogging, added to net return and water productivity compared to subsurface irrigation system. 5-Using aquaculture drainage with Nitrogen fertilizer rate of 60 % achieved the optimum conditions for sesame and onion crops with 40% fertilizer saving compared to traditional methods. So, it is recommended to reuse aquaculture drainage as alternative resource for irrigation to improve the crop yield.