Abstract:
Potato (Solanum tuberosum L.) is one the most important food and cash generating crops in
the eastern parts of Ethiopia, particularly East Harerghe zone, where it is grown three times
per year. However, the average yield of potato is low, due to low soil fertility and poor ferti lizer management practice. Therefore, a field experiment was conducted in 2021 at Damota,
Haramaya district, with the objectives of assessing the influences of integrated use of Farm yard manure and NPS blended fertilizers on growth, yield and yield components and to
estimate cost-benefit of NPS and Farmyard manure for potato production. Factorial combina tions of four levels of NPS rate (0, 50, 100 and 150kgha-1
) and four levels of Farmyard
manure (0, 10, 20 and 30 t ha-1
) were laid out in a Randomized Complete Block Design with
three replications using improved potato variety Bubu as a test crop. Results of the research
revealed that both the main and interaction effects of mineral NPS fertilizer and Farmyard
manure significantly influenced all phenology, growth, yield and yield related parameters of
the crop except unmarketable number of tubers and unmarketable tuber yield. The plants that
supplied 30 t ha-1 FYM and 150 kg ha-1 NPS fertilizer had significantly delayed days flower ing, significantly highest number of main stems, leaf area, proportion of large and medium
sized tubers, specific gravity, dry matter and starch contents of tubers. The interaction of 150
kg ha-1 NPS with 20 and 30 t ha-1 FYM significantly delayed maturity of potato and the inter action of 150 kg ha-1 NPS fertilizer with 10, 20 and 30 t ha-1 FYM significantly increased the
height of plants. The interaction of 100 kg ha-1 NPS fertilizer with 30 t ha-1 FYM significantly
increased marketable and total tuber number per hill while the interaction of 150 kg ha-1 NPS
with 30 t ha-1 FYM significantly increased tuber mass per hill. The variety produced highest
total and marketable tuber yield of 41.63 and 40.36 t ha-1
, respectively, due to the interaction
effect of 150 kg ha-1 NPS fertilizer with 30 t ha-1 FYM. The highest net benefit of 378302 Birr
ha-1 with acceptable marginal rate of return of 1276.5% was obtained from the application of
150 kg ha-1 NPS +30 t ha-1 FYM. Therefore, the combined application of 150 kg ha-1 blended
NPS fertilizer and 30 t ha−1 Farmyard manure could be provisionally recommended
forʻʻBubu ̓ ̓ variety production in the study area
