Abstract:
Potato (Solanum tuberosum L.) is one of the most important tuber crops which is being
produced in Ethiopia. However, the production and productivity of the crop is far below the
world average due to poor crop variety, soil fertility and water management practices.
Therefore, a field experiment was conducted in Southwestern Ethiopia ‘Seka district, under
irrigation during the 2018/2019 off-season. Treatments consisted of four levels of NPSB (0,
61, 122 and 183 kg ha-1) and four levels of cattle manure (0, 10, 15 and 20kg ha-1) laid out
in Randomized Complete Block Design (RCBD) in a 4x4 factorial with three replications.
Data were collected on growth and yield parameters. The combined application of NPSB
blended fertilizer and cattle manure significantly (P<0.005) influenced days to 50%
flowering, days to 75% physiological maturity, plant height, total tuber yield (t ha-1),
marketable tuber yield (t ha-1), total tuber number per hill, marketable tuber number per hill
and specific gravity. However, main stem number and dry matter content were not affected by
the combined application of NPSB blended fertilizer and cattle manure. Unmarketable tuber
number and yield was also not affected by the main effects of NPSB blended fertilizer and
cattle manure and as well as their interaction. The highest total tuber yield (40.08 t ha-1) was
obtained by applying 183 kg ha-1 NPSB bended fertilizers+20 t ha-1 cattle manure. The
combined application of 183 kg NPSB ha-1 bended fertilizers+20tha-1 cattle manure gave the
maximum net return of Birr 193365.5ha-1 with an acceptable marginal rate of return (1726
%). The total nitrogen, available phosphorus and organic carbon content of the experimental
soil were also increased due to the interaction of mineral NPSB blended fertilizers and cattle
manure at their highest rates. The combined application of 122 kg ha-1NPSB blended
fertilizers and 10 t ha-1 CM is found economically feasible for farmer which un able to buy
much input. In conclusion, the results revealed that combined application of 183 kg ha-1NPSB
fertilizers and cattle manure at 20 t ha-1 significantly increased total tuber yield (40.08tha-1)
of potato and restore of N, P and organic carbon of soil. And can be recommended for potato
growers around Seka district.
