Effect of nitrogen rates and irrigation regimes on Water and nitrogen use efficiencies of selected Potato varieties

Abstract

mong African countries, Ethiopia has possibly the greatest potential for potato production. But its contribution to food security is less due to poor agronomic techniques and other factors which require improving the ways of resources use and increasing farm return. This experiment was conducted in JUCAVM greenhouse to study the effect of nitrogen rates and irrigation regimes on water and nitrogen use efficiency of selected potato varieties (Jalenie, Guassa and Degemegn), using three nitrogen rates (130, 110, 90 kg/ha), and three irrigation regimes (full irrigation (100%), 80% and 60% of full irrigation) on clay textured fine top soil filled to poly ethylene pot of 15 liter and 30 cm upper diameter. The experiment was 3x3x3 factorial with three replications laid down in a Randomized Complete Block Design. Interaction of variety and irrigation significantly affected water use efficiency (WUE). Jalenie variety recorded the highest WUE at 80% irrigation, but was on par with Guassa varieties at 100% irrigation. The lowest WUE was obtained from Degemegn variety at 100% irrigation even though there was no significant difference among the three irrigations. Irrigation and variety was significantly affected the nitrogen utilization efficiency while only irrigation highly significantly influenced the nitrogen up take efficiency. Guassa and Jalenie produced statistically similar maximum nitrogen utilization efficiency while Degemegn provided lowest. Significantly the highest nitrogen utilization efficiency was recorded at 100% irrigation and the least was obtained at 60% irrigation, while 80% irrigation statistically similar to both irrigation effects. The highest nitrogen up take efficiency was recorded at 100% irrigation, followed by 80 and 60%. From the results, it can be concluded that irrigation regimes and variety were significantly affected water and nitrogen use efficiency of the potato varieties while the nitrogen rates and interaction between or among factors holding nitrogen combination were not influenced the water and nitrogen use efficiency of the potato varieties significantly. As this is output of greenhouse condition, open field experiment is suggested to be carried out to come up with conclusive results.