Abstract:
Northern Gondar is one of the areas where bread wheat is cultivated widely in the Amhara
region. However, wheat productivity in the area is low (2.75 t ha
-1
) as compared to the world
average (3.63 ton ha
-1
). Low soil fertility, especially nitrogen (N) deficiency, is one of the
major constraints limiting wheat production in the area. Thus, this experiment was conducted
at Dabat and Debark districts in Northern Gondar at farmer’s field during the main rainy
season of 2017. The objective of the study was to investigate the effect of nitrogen rate and
time of application on growth, yield, grain protein content, and N use efficiency of bread
wheat. A factorial combinations of four nitrogen rates(46, 92, 138 and 184 kg N ha
) and
three nitrogen application times (full dose at sowing, ½ at sowing+½ at mid-tillering and 1/3
at sowing+1/3 at mid-tillering+1/3 at heading) were tested in RCBD with three replications.
Combined analysis of variance revealed that all the parameters evaluated were affected by
the main effect of N fertilizer rate. The highest growth, yield, yield components and quality
parameters of bread wheat were obtained by application of 184 kg N ha
-1
. Among application
times two equal split application of nitrogen resulted in the highest plant height, above
ground biomass and grain yield while three equal split application of nitrogen gave the
highest spike length and quality parameters. Days to heading and physiological maturity
were prolonged in response to increasing the rate of nitrogen. The maximum NUE traits were
obtained at lowest nitrogen rate. Split application of nitrogen ½ at sowing and ½ at midtillering
resulted in the highest NUE except physiological efficiency in which full dose
application gave the highest efficiency. In conclusion, based on the result obtained in partial
budget analysis application of 184 kg N ha
-1
in two equal split gave the highest grain yield
and optimum quality of bread wheat with highest net benefit and attractive MRR as compared
to all other treatments.
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