Water-Use Efficiency and Ammonium-N Source Applied of Wheat under Irrigated and Desiccated Conditions

Abstract

Pot experiment laid out to study the effects of watering, nitrogen fertilization, and their interactions on the growth, dry matter production and water use efficiency of two cultivars(Egyptian Sakha94 cultivated in 2009/2010 season and Turkish Adana99 cultivated in 2010/2011 season) of wheat. The experiment laid out in randomized complete design. Cultivars were grown in pots at the greenhouse of the Faculty of Life and Environmental Science, Shimane University during 2009/2010 and 2010/2011 growing seasons. Two watering levels started after booting stage (well-watered and desiccated) and five nitrogen fertilization levels0.0, 0.24, 0.48, 0.72 and 0.96g pot-1 (0.0, 75, 150, 225, 300kg N h-1) respectively, were designed. Our objective was to determine the effect of nitrogen (N) from ammonium sulfate split-applied at different rates before anthesis on water use efficiency under well-watered and desiccated conditions in the recent Egyptian cultivarSakha94 and Turkish Adana99 used in pots. The results showed that the leaf area, shoot dry matter production at anthesis, total dry matter production, number of spikelet’s spike-1, number of spikelet’s pot-1, number of spikes pot-1, spad value after sowing to anthesis time, consumptive use and water use efficiency of wheat increased with increasing level of nitrogen under well-watered conditions for both cultivars, but the stomatal conductance and transpiration rate decreased under desiccated conditions. No significantly difference among N levels under desiccated conditions. It was considered that under our experimental condition applied 0.96 g N pot-1 (300 kg N ha-1) led to significantly increase in WUE in both cultivars under irrigated and desiccated conditions. However, WUE was significantly higher in desiccated conditions than irrigated conditions in in Sakha94 than Adana99. May the primary cause of increased WUE, decreasing leaf chlorophyll concentration, photosynthesis rate and stomatal conductance (gs).