Response of Potato(Solanum tuberosum L.)to Potassium Fertilizer on Acid Soils of Wolmera and Gumer Weredas,in the High Lands of Ethiopia

An experimenton the effect of K fertilizer on potato was conducted under on station and on farm condition ofHoleta, Bedi and Gumer weredasin 2012 and 2013 cropping seasons. The experiment comprised of eight treatments with 3 replicationsarranged in RCBD design. The treatments were absolute control, recommended rate of NP(165 kg ha-1 urea and 195 kg ha-1 DAP), recommended rate of NP combined with 25, 50 and 75 kg ha-1 K2O (From potassium sulfate (K2SO4)and potassium chloride (KCl). DAP was applied as basal application at planting whereas urea was applied in split i.e.half at planting and the rest half one month after planting. K2SO4 and KCl were used as K sources and were applied as basal at planting. Potato variety Gudane was used as test variety at all locations. Results combined over years and sites showed that the highest potatotuber yield and number of tubers per meter square was obtained from the plots that received 75 kg ha-1K2Ofrom K2SO4. At all sites allrates and types of K fertilizer applied had significantly increased tuber yield with the benefit ranging from 60 to 149% over the control. The pooled data in each location indicated that both types of K fertilizers and all K rates gave significantly higher tuber yields (ranging from 24.1 to 32.4 t ha-1) as compared to the recommended rate of NP (20.8 t ha-1). Particularly the application of K2SO4 gave significantly higher tuber yieldsof potato than that of KCl receiving similar rates at Bedi and Holeta, but not at Gumer site. Keywords: soil acidity, potassium,highlands, lime, potat