ABSTRACT
Aims: To improve the nutritional values of carrot in the Great North Cameroon by using natural fertilizing. Study Design: A 11x2x2 factorial design with 11 origins of carrot roots (fertilizing) (T0, T+, P10, P15, Py10, Py15, F1, F1+P10, F1+P15, F1+Py10 and F1+Py15), 02 harvest areas (Maroua and Ngaoundere (Cameroon)) and 02 harvest years (2019 and 2020). Place and Duration of Study: Laboratory of Biodiversity and Sustainable Development, University of Ngaoundere Cameroon, September 2019 and September 2020. Methodology: Nutrient parameters of carrot roots (moisture, vitamin C, carotenoids, fiber, carbohydrates and ash of carrot roots contents) were assessed according to standard methods. Results: Globally, carrot nutritional values varied significantly (p<0.05) depending on fertilizer, harvest area (Ngaoundere and Maroua Cameroon), and harvest year (2019 and 2020). The carrot nutrient contents from Maroua Cameroon were higher than those from Ngaoundere. The highest carrot nutrients content was from F1+P10 plots (combination of 1 Kg of poultry litter with 10 g of vivianite powder). In Maroua, roots from treated carrot plants with F1+P10 fertilizer are 1.55 and 1.24 fold richer in carotenoids than those from T0 and T+ plants respectively in 2019 ; in growing year 2020, the carotenoid contents of F1+P10 roots were 1.52 fold and 1.29 fold higher than those of T0 and T+ plants. In Ngaoundere, Vitamin C content of carrots from F1+P10 fertilizer is 1.79 fold higher than that of T0 plants and 1.18 fold higher than that of T+ plants in 2019, while in 2020 the value of this parameter was 1.69 fold and 1.47 fold higher than that of T0 and T+ plants respectively. The F1+P10 fertilizer encreased total carbohydrate content at 51.88 % compared to T0 and 20.03 % compared to T+ in Maroua, and at 27.59 % and 7.95 % compared to T0 and T+ respectively in Ngaoundere. Conclusion: By used F1+P10 natural fertilizer for carrot growing, we contribute to improve the nutritional values of this vegetable crop, but also to valorize our local resources in biological agriculture, as well as to protect the environment.