Influence of NPSB Blended Fertilizer and Cattle Manure Rates on Growth, Yield and Quality of Carrot (<i>Daucus Carota</i> L.) in Horro District, Western Ethiopia

Carrot (Daucus carota L.) is an important vegetable crop in Ethiopia, yet its productivity remains low due to poor soil fertility and inadequate nutrient management. This study, conducted in 2024 at Gitilo Dale, Wollega University, Shambu Campus, Western Ethiopia, aimed to evaluate the effects of integrated nutrient management using cattle manure (CM) and NPSB blended fertilizer on the growth, yield, and quality of carrot. A field experiment was laid out in a Randomized Complete Block Design (RCBD) with 16 treatments comprising four levels of CM (0, 6, 10, and 14 t ha⁻<sup>1</sup>) and four levels of NPSB fertilizer (0, 60, 100 and 140 kg ha⁻<sup>1</sup>), replicated three times. Key agronomic parameters such as plant height, number of leaves, aboveground biomass, root yield, and quality traits including root length, diameter, fresh weight, length-to-diameter ratio, and dry matter content were measured. Results revealed that the combined application of 10 t ha⁻<sup>1</sup> CM and 100 kg ha⁻<sup>1</sup> NPSB significantly (p < 0.01) enhanced all growth, yield, and quality attributes compared to the control. The highest total root yield (39.5 t ha⁻<sup>1</sup>), root length (17.8 cm), root diameter (3.8 cm), and dry matter content (14.8%) were recorded under this treatment. Conversely, the lowest performance was observed in the untreated control. The study concludes that integrating organic and an inorganic fertilizer improves carrot productivity, root quality, and soil health. Therefore, the combined use of 10 t ha⁻<sup>1</sup> CM and 100 kg ha⁻<sup>1</sup> NPSB is recommended for sustainable carrot production in the highlands of Western Ethiopia.