Response of Potato to nitrogen and phosphorus fertilizer at Wag-Lasta Areas of Eastern Amhara, Ethiopia

Abstract Background: Production and productivity of potato in Ethiopia is far below the world average due to soil fertility problem, pest, disease, and agronomic factors. Nutrient depletion due to soil erosion is a serious problem in Ethiopian highlands. Annually, nitrogen 122 kg ha-1 P 13 kg ha-1 and K 82 kg ha-1 were estimated to deplete from Ethiopia (Haileslassie et al., 2005). The essential nutrients like, nitrogen and phosphorus are the most important influential nutrient for the production of potato but they are deficient in most Ethiopian soils and thus an application of these nutrients could increase significantly the crop yields. In this context, an experiment was conducted at Sekota and Lasta Lalibela districts (Woleh and Kechin Abeba irrigation command areas) of eastern Amhara to investigate the effects of nitrogen and phosphorus fertilizers for yield and yield component of potato under irrigation condition. Methods: Four rates of nitrogen (0, 46, 92, and 138 kg N kg ha-1) and four rates of phosphorus (0, 23, 46, and 69 Kg P2O5 kg ha-1) were combined in the factorial arrangement and laid out in randomized complete block design with three replications. Results: The result of the study revealed that nitrogen and phosphorus had a significant effect on plant height, marketable, and total yield of potato at Kechin Abeba. But phosphorus did not show a significant effect on plant height and unmarketable yield at Sekota district of Woleh irrigation command area. The highest yield 45.55 t ha-1 was obtained from in combined application of 138 N and 23 P2O5 in Lalibela and 17.12 t ha-1 was obtained from in combined application of 138 N kg ha-1 and 46 P2O5 kg ha-1 from Sekota districts of Woleh irrigation command area. Conclusion: The application of nitrogen and phosphorous fertilizer in the study area were more efficient in terms of tuber yield in Lalibela (Kechin Abeba) than Woleh. The application of 138 kg ha-1 N combined with 23 kg ha-1 P2O5 is found to be the appropriate rates for optimum productivity of Potato at Lalibela (Kechin Abeba) and Sekota (Woleh) under irrigation conditions and the same agro-ecology.