Soil K Status and K Requirement of Potato Growing on Different Soils of Western Amhara

An experiment was conducted in 2005/06 and 2006/07 cropping seasons on Nitosols, Acrisols and Luvisols of Western Amhara to investigate the inherent soil K status and K requirement of potato growing on ·these soils. The field experiments were conduckd in Yilmana Densa (West Gojjam Zone), Farta (South Gondar Zone) and Banja (Awi Zone) woredas. Soil samples were collected from experimental sites before planting of potato and analyzed for exchangeable K status. The treatments included in the field experiment were 6 levels of potassium fertilizer (0, 30, 60, 90, 150 and 210 kg K20 ha-1) that were arranged in randomized complete block design with three replications. All of the K fertilizer for each treatment was band-applied at planting along and in one side of the rows at a distance of 5 cm below and 5 cm aside the seeds. Muriate of potash (KC!) was used cJS a source of K. Moreover, 81 kg N and 69 kg P205 (recommended rates for western Arnhara) were added to all plots. This was done by applying 150 kg OAP and 58.5 kg urea at planting and side dressing 58.5 kg urea at flowering stage. Results of the experiment indicated that there was no significant increase in potato tuber number, plant height, number of main stems per plant, potato dry matter yield due to increase in K fertilizer rate on Nitosols, Acrisols and Luvisols. However, increase in K fertilizer rate significantly increased mean tuber weight and tuber yield of potato on Acrisols of Banja Woreda and. improved shelving life of potato collected from all soil types.Key words: Acrisols, Luvisols, Nitosols, Potassium, Potat