الفهرس 
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Abstract
The present dissertation aimed to investigate the evaluation of surface irrigation under different treatments of water discharge and nitrogen fertilizer levels. A field experiment was conducted using variety Sakha 93 during the two growing seasons of 2004/2005 and 2005/2006 at Sakha Agriculture Research Station Farm to study the effect of different border width, irrigation discharge and nitrogen fertilizer levels on wheat crop yield and some water relations. The split split plot design with four replicates was used. The main plots randomly assigned to three border widths (7, 11 and 15 m, the sub plots to three irrigation discharge (2.5, 3 and 3.5 L.sec-1.m-1) and the sub sub plots to three nitrogen levels (80, 100 and 120% N from recommended dose). The results showed that the best treatments regarding wheat grains, straw and 1000 grains were achieved with 11 m border width, 3.0 and 3.5 L.sec-1m-1 irrigation discharge and 120% N from recommended dose followed by 15 m border width, 3.0 or 3.5 L.sec-1m-1 irrigation discharge and 120% from recommended dose as well as it resulted in long panicle length, plant height and leaf area. The highest the concentration of nitrogen and uptake by wheat grains and straw were achieved with 11 m border width, 3.0 or 3.5 L.sec-1m-1 and 120% N form recommended dose. The highest values of fertilizer use efficiency were achieved under the same treatment. The amount of applied water and the water consumptive use were increased with increasing border width, and decreased with increasing irrigation discharge and vice versa. The soil moisture extraction patterns for wheat crop was decreased with increasing irrigation discharge from 2.5 to 3.5 L.sec-1m-1 and different border width. The highest values of crop and field water use efficiency for wheat grains were achieved with 11 m border width, 3.5 L.sec-1m-1 irrigation discharge and 120% N from recommended dose. Water distribution efficiency was decreased as border width increased specially under water discharge 2.5 and 3 L.sec-1m-1. While, it tended to increase under 3.5 L.sec-1m-1. The opportunity time of irrigation water to the border end, increased with increasing border width, and it decreased with increasing irrigation discharge and vice versa. The water applied and depth infiltrated were decreased with increasing irrigation discharge under different border widths. In this respect, the infiltrated depth increased with increasing border width under the same discharge.