Two field experiments were conducted during the two growing seasons of study 2004/2005 and 2005/2006 at Sakha Agricultural Research Station Farm to study the effect of different border widths, water discharge and nitrogen fertilizer on irrigation efficiencies.
The split split plot design with four replicates was used. The main plots randomly assigned to three border width (7, 11 and 15 m), the sub plots to three irrigation discharge (2.5, 3 and 3.5 L. sec-1m-1) and the sub sub plots to three nitrogen fertilizer levels; 80, 100 and 120% N from recommended dose (75 kg N fed-1).
The results revealed that the highest values of field and crop water use efficacy by wheat grain yield were obtained from 11 m border width, 3.5 L. sec-1m-1 water discharge and 120% N from recommended dose. While the highest field water use efficiency by straw yield were achieved from 7 m border width, 3 L. sec-1m-1 water discharge and 120% N from recommended dose. Moreover, the highest crop water use efficiency by wheat straw yield were obtained from 11m border width, 3 L. sec-1m-1 water discharge and 120% N from recommended dose.
The highest values of irrigation application efficiency were obtained from 15 m border width, 3.5 L. sec-1m-1 water discharge and 120% N from recommended dose.
The value of 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 water discharge with increasing border width. The opportunity time between advance and recession time of irrigation water to the border end, increased with increasing border width, decreased with increasing irrigation discharge and vice versa.
It could be recommended that the combination of 11 m border width, 3.5 L. sec-1m-1 water discharge and 120% N from recommended dose achieved the best irrigation performances followed by 15 m border width, 3.5 L. sec-1m-1 water discharge and 120% N from recommended dose at North Nile Delta.