IRRIGATION SCHEDUL WITH DIFFERENT NITROGEN SOURCES AND LEVELS FOR MAIZE PRODUCTIVITY AND SOME WATER RELATIONS

Two field experiments were conducted in two successive summer seasons during 2016 and 2017 at Sids Agricultural Research Station, Beni-Suef Governorate, Egypt. This research was carried out to study irrigation schedule impact using pan evaporation method (Class A pan and irrigation at 0.7, 1.0 and 1.3 pan evaporation coefficient, APE) with different nitrogen sources (ammonia gas, ammonium nitrate and urea) and levels (214 and 286 kg N ha-1) on maize yield attributes as well as some water relations, namely, seasonal applied water (AP), seasonal consumptive use (CU), water utilization efficiency (WUtE) and water use efficiency (WUE). Results showed that increasing pan evaporation coefficient from 0.7 up to 1.3 increased maize yield and improved its attributes, N, P and K uptake by grains and/or stover, seasonal applied water and seasonal consumptive use. The differences between the effect of 1.0 and 1.3 of APE on maize grain and stover yields were not significant. Irrigation at 1.0 APE gave the highest WUtE and WUE followed by irrigation at 1.3 APE. Whereas the lowest one produced under 0.7 of APE Added nitrogen as anhydrous ammonia increased all studied yield and its attributes, N, P and K uptake, seasonal consumptive use, water utilization efficiency and water use efficiency followed by ammonium nitrate, while urea fertilizer exhibited the lowest ones. Increasing nitrogen levels from 214 to 286 Kg ha-1 improved maize yield and its attributes, N, P and K uptake as well as the studied water relations. The best treatment for maize productivity and water relation is to irrigate at 1.0 of APE with nitrogen addition as ammonia gas at the rate of 286 Kg ha-1 while saving about 960 m3 per hectare with no significant decrease in yield. This study confirms that maize irrigation at different pan evaporation coefficient (0.7, 1.0 and 1.3) with different nitrogen fertilization sources and levels affect maize productivity traits and some water relations.