Potential influence of nitrogen fertilizer rates on yield and yield components of carrot (<i>Dacus carota</i> L.) in Ethiopia: Systematic review

Abstract

Abstract Carrot is a significant root crop in Ethiopia but its production faces challenges such as nutrient loss and unfavorable growth conditions, which hinder its productivity. The objective of this review was to evaluate the impact of nitrogen fertilizer rates on carrot yield in Ethiopia. A systematic review using databases like PubMed and Scopus focused on peer-reviewed, English-language studies with quantitative data on nitrogen fertilizer and carrot yield in Ethiopia, excluding non-peer-reviewed articles and those lacking quantitative data or in other languages. Globally, carrot yields are 30–100 tons per hectare, but only 5.5 tons in Ethiopia. Carrots are rich in vitamins A, C, and B, proteins, minerals, and fiber, with vitamin C boosting immunity and aiding in wound healing and allergy management. Meanwhile, vitamin A plays a crucial role in vision, bone growth, immune function, and reproduction. It is a rich source of carotenoids and anthocyanins. The application of nitrogen fertilizer significantly improved carrot yield (root length, fresh weight, and dry weight). In Ethiopia, the use of nitrogen fertilizer affects the marketability and total yield of carrots, with small-scale farmers employing diverse rates for cultivation. Current recommendations suggest 69 kg/ha of phosphorus (P 2 O 5 ) and 46 kg/ha of nitrogen, but farmers often do not follow these guidelines. In conclusion, optimizing nitrogen fertilizer usage is crucial for enhancing carrot yields among small farmers, underscoring the need for government support to tailor recommendations to local soil conditions and boost productivity.