Evaluation of Potassium Fertilizer on Yield and Yield Components of Potato under Irrigation on Nitisols in Central Highlands of Ethiopia

Nutrient deficiency is a major constraint for potato ( S olanum t u berosum L.) production in Ethiopia. Potato response to potassium fertilizer declined with widespread deficiencies of nutrients other than N and P, farmers are discouraged to apply such fertilizer recommendations. This study was, therefore, conducted for two years (2018-2019) on nitisols under irrigation to evaluate the response of potato to potassium (K) fertilizer rates. The treatments were five (Negative control, recommended NPS, recommended NPS, recommended NPS + 3liter K /ha, recommended NPS + 5 liter K/ha, recommended NPS + 7liter K/ha). The experiment was arranged in a randomized complete block design replicated four times on farmers’ fields. Results revealed that potato yield responded differently to the applied potassium fertilizer rates. Applications of 100% NP fertilizer with 5liter/ha potassium fertilizer had a significant (p<0.05) effect on marketable tuber and total tuber yield of potato. In general application of liquid potassium fertilizer (100% NP fertilizer with 5liter/ha K) indicates positive response on dray matter and specific gravity. In conclusion, based on the findings of the experiment with application of 5L/ha liquid potassium fertilizer with 100% recommended NP fertilizer are economically optimum for potato production. Keywords : Liquid fertilizer, Nitisols, Potassium, Potato DOI: 10.7176/JNSR/10-12-02 Publication date: June 30th 2020