Awaad M.S., M. A. El shazly, M. B. Taha and I. M. Abdalla( 2020). Effect of different nitrogen rates and sources with irrigation of wheat and maize cropsMenoufia J. Soil Sci., Vol. 5 October (2020): 173 – 185
Abstract: Two field experiments were carried out during winter season (2016/2017) and summer season (2017) an clay soil to evaluate the effects of N management practices with irrigation on wheat and maize crop, nitrogen fertilizers were added before or after irrigation as a three sources of N (urea, ammonium nitrate and ammonium sulfate) on vegetative growth, production of yields, NPK content in grains of both wheat and maize as well as nitrogen recovery. The treatments included four doses from recommended dose ( 0, 60, 80 and 100 %). The N was splitted into three doses (50% at sowing + 25% at maximum tillering + 25% at spike initiation) for wheat crop. wterever, the N was applied at four splits dose ( at third leaf stage, ninth leaf stage, tasseling and milking stage) for maize crop. Results of indicated that, application of nitrogen at high er doses after irrigation led to increasing vegetation growth of both wheat and maize plants. Also, the same treatment produced the highest values of straw, grain yields, biological yield and harvest index of both wheat and maize compared to the other treatments. Macronutrients (N,P and K) uptake, and this addition of nitrogen fertilizers at high dose produced the highest values of macronutrients uptake by both grains of wheat and maize compared to the other treatments. Generally, nitrogen application after irrigation resulted in the highest values of nitrogen recovery compared with the nitrogen application before irrigation. Hence, it could be concluded that the best results were obtained when nitrogen applied after irrigation with both wheat and maize crops.
Keywords: (Irrigation, Nitrogen fertilizers, Nitrogen Recovery , Wheat , Maize .)
