Abstract:
The deficiency of soil nutrients is the major constraint for potato production in Ethiopian
highlands in general and in central highlands of Ethiopia in particular. To determine the
optimum application rate of 45 days decomposed vermicompost and NPS blended fertilizer for
sustainable potato production in central Ethiopian highlands at Debre Berhan. This experiment
was conducted in 2019/20 main season by using Belete potato variety (CIP-393371.58) at Debre
Berhan area. The rate of vermicompost was determined by based on its inorganic N content.
Factorial combinations of three rates of vermicompost (2.5, 5, 7.5 t ha-1) with three rates of
inorganic NPS (25%, 50%, 75%), full dose of vermicompost (7.5 t ha-1), recommended blended
fertilizer 100% NPS (55.5:89.7:16.52 kg ha-1 NPS) and control treatments were laid as factorial
Randomized Complete Block Design (RCBD) with three replications. The result of this
experiment show that integrated use of 75% blended NPS fertilizer and 7.5 t ha-1 vermicompost
increased the residual soil OC, total N, available P and available S by 54.29%, 242.86%,
172.38% and 22.08, respectively as compared to the control. But pH was decreased from 7.2-6.3
or by 12.5% and also exchangeable sodium was dramatically decreased, the correlation analysis
result show that the total tuber yield was positively correlated with total N (r=0.56**), available
P (r= 0.71**) and organic C (r= 0.62**). On top of this, Moreover, the results also showed that
application of 7.5 t ha-1 VC +75% blended NPS fertilizer significantly increased marketable
tuber number, marketable tuber yield and total tuber yield by 127.85%, 119.6 and 96.67%,
respectively as compared to the unfertilized plot. It can be conclude that applications of
vermicompost along with bended NPS fertilizer improve residual soil physiochemical properties
which in turn increased crop yield. Hence , in order to maintain soil fertility and sustain
potatoes plant crop production farmers of the study area and similar agro ecologies are
advised to make integrated use of vermicompost at (7.5t ha-1) and blended NPS fertilizer
