Abstract:
Low soil fertility problems, particularly nitrogen depletion is one of the main
problems observed for lower barley production in the highlands of Ethiopia. The field
experiment was conducted at Beyeda district in the 2020/21 cropping season to
quantify the insitu soil N status under different land use types and then to determine
the optimum N application rates for malt barley production without affecting its grain
quality. The LUTs identified for evaluation were natural forest, cultivated land and
grazing lands, from which the N application rate determination experiment was
conducted on the cultivated land. The treatments consisted of five levels of N rates (0,
23, 46, 69 & 92 kg N ha
-1
) laid out in RCBD with three replications. The analysis
results of the collected nine composite soil samples revealed that the lower (0.08%)
total nitrogen content was observed in cultivated land unlike forest lands with higher
(0.31%) and grazing lands with medium (0.18%) total nitrogen values, soil reaction
ranged from slightly acidic (grazing land) to neutral (forest and cultivated lands),
with low, medium and high organic carbon values (cultivated land, grazing land, and
forest lands, respectively), AvP was medium in cultivated land and low under grazing
and forest lands. Concerning physical properties sand particle sizes was significantly
(p<0.001) higher in forest lands than in cultivated lands. The clay particle size
determinations results showed a reverse trend such that it was significantly higher in
cultivated than in forest lands. When expressed in terms of textural classes; loam,
clay loam and clay textural classes characterize soils in forest, grazing and cultivated
lands, respectively. Grain yield and yield parameters were significantly (p<0.01)
influenced by N rates. The highest grain yield (4.50 t ha
-1
) was obtained from the
application of 92kg N ha
-1
; but 69kg N ha
-1
was economically reasonable and
acceptable in terms of quality parameters. As such, most grain quality parameters
were not significantly (p>0.05) affected except grain protein. The highest grain
protein (12.3%) was recorded at a rate of 92 kg N ha
-1
. Therefore, for quality malt
barley production in Beyeda district for soils similar with the experimental site in soil
N status, application of 69kg N ha
-1
is recommended.
