Effect of nitrogen rates on Grain yield, yield attributes and nitrogen use efficiency of some distichon barley varieties in sandy soil

Field experiments were conducted at Agriculture faculty farm, Sebha University during the 2006/2007 and 2007/2008 winter seasons to study the response of some distichon barley varieties to nitrogen rate in sandy soil. The experiment was laid out in randomization complete blocks design (RCBD) using split-plot arrangement with three replications. The three distichon barley varieties (Wadiotpa1, Wadiotpa2 and ACSAD 1820) were assigned to the main plots. The sub-plots were allocated to the N rates (125,150,175,200 and 225 kg N/ha). The results indicated significant differences between barley varieties in all studied traits in both seasons. Wadiotpa2 variety surpassed the other two varieties in all traits except 1000- kernel weight which reacted to Wadiotpa1 variety. Grain yield kg/ha and its attributes were increased significantly in the two growing seasons by increasing N rates up to 225 kg N/ha. While, nitrogen use efficiency( NUE) decreased with increasing N rates. Significant interaction between varieties and N rates was detected for all studied traits in both seasons. The maximum grain yield per hectare (3420.20 and 3500.20 kg/ha in first and second seasons, respectively) were obtained from Wadiotpa2 variety fertilized by 225 kg N/ha. While, the highest NUE values (19.12 and 20.00 kg grain /kg nitrogen applied in 2006/2007 and 2007/2008 seasons, respectively) were reported from application of 125kg N/ ha to Wadiotpa2 variety.