Thesis Abstract and Dissertation Abstracts

Egypt, as country of the arid region (modest precipitation of 100-200 mm year-1), will face a scarce of irrigation water, due to increase population and need more food, so maximizing of available one is a must, especially under localized irrigation system. Such as trickle irrigation system which the main disadvantages is pressure reduction at the end of lateral lines. Closed circuits are considered one of the modifications of trickle irrigation system, and will add advantages to traditional trickle irrigation because it can relieve low operating pressures problem at the end of the lateral lines.

The objectives of the present research were: Studying the effect of different trickle irrigation circuits (one manifold line (CM1DIS), two manifold lines (CM2DIS) and traditional trickle system (TDIS) as a control) ,and lateral line lengths (LLL1= 40 m, LLL2= 60 m and LLL3= 80 m) on : i) some hydraulic parameters, ii) corn (Zea Mays-L) crop productivity, water use efficiency (WUE), fertilizers use efficiency (FUE), and   iii) cost analysis of corn production.

PE tubes lateral lines: Ø16 mm; 30 cm distance, and built-in emitters 4 lh-1 at operating pressure 101.325 kPa. Laboratory tests were conducted at the Agric. Eng. Res. Inst., ARC, MALR, Egypt. Whereas field experiment was conducted at the Experimental Farm of Faculty of Agriculture, Southern Illinois University at Carbondale (SIUC).

Results could be summarized as following:

According to pressure head(m), uniformity coefficient (%) and emitters discharge (lh-1) of trickle irrigation circuits (DIC), it they could be ranked in the following descending order: CM2DIS > CM1DIS > TDIS, meanwhile lateral line lengths (LLL) could be ranked in following descending order: LLL1= (40 m) > LLL2= (60 m) > LLL3= (80 m). In respect to friction loss and coefficient of variation, DIC and LLL could be ranked opposite the previous orders. With respect to flow velocity (ms-1), velocity head (m) and lateral discharge (lh-1), DIC and LLL could be ranked in the following descending orders: CM2DIS>CM1DIS>TDIS and LLL3>LLL2>LLL1, respectively. According to the validation of predicted and measured energy head loss, the regression analysis between predicted and measured values were significantly at the 1 % level, under different DIC and LLL treatments. Concerning to vegetative growth parameters: one leaf area (cm2), plant height (cm), leaf length (cm) and number of leaves plant-1, DIC and LLL, used them could be arranged in the following descending orders: CM2DIS > CM1DIS > TDIS and CM2DIS > CM1DIS > TDIS under, respectively. According to grain and Stover water use efficiency and fertilizers use efficiency, DIC and LLL were used could be arranged in the following descending orders: CM2DIS > CM1DIS > TDIS and CM2DIS > CM1DIS > TDIS under, respectively. Cost analysis indicated that modified circuits DIC, CM2DIS and CM1DIS, meanwhile the shorter LLL, LLL1 and LLL2 achieved the highest values of revenue net profits, economic net income from irrigation water and physical net income from irrigation water.

Dissertation Images:
	Dr. Hani A. Mansour (click to enlarge)