Abstract:
Cabbage (Brassica oleracea var. Capitata L.) is one of the most important vegetable crops in
Ethiopia. However, the yield of the crop is low as compared to its potential yield due to low
rates application of fertilizers. The use rates of fertilizer are one of the cultural practices that
help to increase the productivity of the crop. Therefore, a field experiment was conducted to
evaluate the effects of blended NPS and nitrogen fertilizer rates on the yield and quality of
head cabbage at Rare research site of Haramaya University during the 2022 cropping
season. The treatment consistedof a factorial combination of four rates of blended NPS
fertilizer (0, 50 100, and 150 kg ha-1
) and five rates of nitrogen fertilizer (0.23, 46, 69, and 92
kg ha-1
). The experiment was laid down in a randomized complete block design with three
replications using a variety Copenhagen market. Analysis of variance revealed that the
application of NPS and N fertilizer significantly influenced the phenology, growth, yield
component, and quality traits of cabbage plants. Head cabbage treated with the highest dose
of 150 kgha-1 NPS and 92 kg ha-1 N gave a maximum score in growth, early 50% head
initiation and maturity of 55 and 88.5 days, plant spread of 60.2 cm, plant height of 35.9 cm,
10.1 wrapping leaves, total head weight and head weight of 3.2 and 2.9 kg, head diameter
and height of 18.7 and 17.9, marketable cabbage head yield of 62.87 t ha-1,
head compactness
of 0.06 and head dry matter of 8.63%. The results of the partial budget analysis showed that
application of 150 kg ha-1 NPS and 92 kg ha-1 N had a net benefit of Birr 364,797 and a
marketable yield of 62.8 t ha-1with marginal rate of return of 803% which is above the
minimum acceptable level. Therefore, a combined application of 150 kg NPS and 92 kg N ha-1
could be considered for head cabbage production in Haramaya area and areas with similar
agro ecological and soil conditions. However, since the rates used in this study were not
sufficient to satisfy crop fertilizer requirements, the inclusion of higher doses of fertilizers in
the future research line is suggested.
