Abstract:
A field experiment was conducted at Dabat, northwestern Ethiopia to determine the optimum
and economically feasible nitrogen and phosphorus fertilizer rates for potato production under
rainfed condition. To evaluate the optimum and economically feasible Nitrogen and
Phosphorus fertilizer rates for potato production under rain-fed condition in Dabat District.The
productivity of potato crop in the study area is low due to soil fertility problem. Four rates of
nitrogen (0, 55, 110 and 165 Kg ha
-1
) and four rates of phosphorus (0, 20, 40 and 60 Kg ha
-1
)
were combined in 4 x 4 factorial arrangement and laid down in randomized complete block
design with three replications. Improved potato variety known as “Belete” was used as a test
crop. The results of the study revealed that both the main and interaction effects of nitrogen
and phosphorus on most of the studied yield and yield component parameters of the crop were
significant. The overall the result of this study showed that different nitrogen and phosphorus
rates and their interactions have significant impacts on growth and tuber yield of potato. The
combined effect of different levels of nitrogen and phosphorus revealed that the rate of
nitrogen at a rate of 110 and 55 kg ha
-1
combined with phosphorus at a rate of 40 kg ha
-1
gave
significantly the highest total tuber yield (45.38 and 44.97 t ha
-1
) and marketable yield (39.1
and 39.02 t ha
-1
), respectively. Yield of tubers per hectare was significantly and positively
correlated with plant height, average tuber weight and total number of tuber. Economic
analysis revealed that application of 55 kg N ha
-1
with 40 kg P ha
-1
gave maximum net return
(187,603.6 Birr ha
-1
) with marginal rate of return (3,934%). On the basis of the results of the
present study farmers around Woken Kebele, Dabat district and similar areas can be benefited
by tentatively applying 55 kg ha
-1
of nitrogen in combination with 40 kg ha
-1
phosphorus.
