Nutritional status, fruiting, yield and essential oil of fennel plants (Foeniculum vulgare L.) grown under clay loam soil conditions located at Beni Suwef governorate – Egypt in response to partial replacement of
conventional NPK-mineral fertilizers by NPK-nano fertilizers at 25%, 50% and 75%, were investigated during 2017 and 2018 seasons. Increasing the replacement ratio of conventional NPK-mineral fertilizers by NPK-nano
fertilizers from 25% to 75% was very effective in improving vegetative growth leaf mineral contents (N, P, K, Mg and Ca), and essential oil % rather than using 100% conventional NPK fertilizers. The gradual increasing the ratio of nano NPK fertilizers from 25% to 75% was remarkably enhancing oil yield/plant as well as oil yield/feddan. However, non-significant differences were observed between the two heights ratio 50% and 75% nano-fertilizers ratio.