Efficient nitrogen fertilizer management is being critical for the improved production of wheat and can be achieved through source and timing of N application.
In order to identify the effects of different N fertilizer sources and timing of application on growth, yield and its components of wheat, a field experiment was carried out at the Research Farm of El-Karada – Kafrelshiekh during 2012-2013 and 2013-2014 seasons. The experiment was conducted in saline sodic soil. The used variety was Sakha 93 wheat Varity as salt tolerant verity. The experiment was designed as a split-plot with four replications. The N sources; ammonium nitrate (AN), ammonium sulpahte (AS), Urea (U) and calcium nitrate (CN) were assigned in the main plots. The sub-plots consisted of three timing of N applications, T1= full N dose at sowing, T2= 1/2 N at sowing + 1/2 N at 30 days from sowing, T3= 1/3 N at sowing + 1/3 N at 30 days from sowing + 1/3 N at 60 days from sowing.
Results indicated that:-
The differences traits of growth, yield components, grain yield and harvest index (HI) in the both sources and timing of N application were significant. Ammonium nitrate increased flag leaf area and chlorophyll content but urea increased dry matter production. Ammonium sulphate increased yield components, grain yield and HI as compared to the other N sources.
Split N application especially at sowing, 30 days after sowing and 60 days after sowing had increased all parameters compared to full dose in 2012 and 2013 seasons.
The interaction between sources and timing of N application was significant for flag leaf area, dry matter production, spike length, panicle weight, No. of grains/spike, biological yield, grain yield and HI.
It was concluded that split application of ammonium sulphate or ammonium nitrate performed better than full dose application and the other N sources for improved wheat productivity and thus, is recommended for general practice in saline sodic soil conditions. Furthermore, the ammonium sulpahte application is better than other N- sources under current conditions as chemical amendment since it sulfur bearing fertilizer.