Yield and Quality of Potato as Influenced by the Combined Application of Blended NPS Fertilizer and Farmyard Manure at Debre Berhan, Central Highland of Ethiopia

Potato (Solanum tuberosum L.) plays a vital role in ensuring food security in Ethiopia; however, its production is limited by inadequate soil fertility and imbalances in crop nutrient management practices. Consequently, a research was undertaken to assess how blended NPS fertilizer and farmyard manure influences both the yield and quality of potatoes. The study used a factorial design with four levels each of NPS fertilizer (0, 60, 120, and 180 kg ha-1) and farmyard manure (0, 10, 20, and 30 t ha-1) in a Randomized Complete Block Design replicated three times. The study found that marketable tuber yield was significantly affected by the application of NPS fertilizer and farmyard manure. Specifically, the combined use of 180 kg ha-1 NPS and 30 t ha-1 farmyard manure resulted in the tallest plants (73.26 cm), the highest average tuber weight (88.26 g per tuber), and the highest total tuber yield (32.68 t ha-1). However, these applications did not significantly impact tuber quality. Economically, this combination provided the highest benefit (119,758 Birr ha-1) with a substantial marginal rate of return (1,636.1%). Therefore, it is recommended that potato producers in the study area and similar regions should use 180 kg ha-1 NPS and 30 t ha-1 farmyard manure for optimal yield and economic gain.