Effects of integrated use of vermicompost and NPS blended fertilizer on potato (Solanum tuberosum L.) yield and residual soil physicochemical properties of soils in central highlands of Ethiopi

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