Influence of NPK fertilizer on carrot (Daucus carota L.) growth, root yield, and selected soil physical properties in Katsina State, Nigeria

An experiment was carried out during the 2026 rainy season at the teaching and research farm of the College of Vocational Agriculture Tambu Daura Local Government Area of Katsina, Nigeria, which is located within the Sudan Savanna agro-ecological zone, to ascertain the impact of various rates of NPK fertiliser on growth, root yield, and specific soil properties. Four treatments were employed: 0 kg N:P2O5:K2O ha−1, 20:10:10 kg N:P2O5:K2O ha−1, 40:20:20 kg, and 60:30:30 kg N:P2O5:K2O ha−1. A Randomised Complete Block Design (RCBD) with three replications was used to set up the experiment. Carrot seeds were directly sown on the prepared beds, at a rate of 8 kg/ha, spaced at 15 cm apart and inside rows. Based on the study's results, application of NPK 60:30:30 kg N:P2O5:K2O ha−1 significantly outperformed other treatments in terms of growth characteristics, such as plant height, number, length, and chlorophyll content of leaves, as well as yield characteristics, such as root diameter thickness and root weight of carrot per hectare. Furthermore, applying 60:30:30 kg N:P2O5:K2O ha−1 yielded 12,314 kg/ha, which is significantly more than other treatments. Nevertheless, the carrot's root length and biomass above ground were not significantly affected by any of the treatments. It is recommended that farmers in Daura local Government area and Sudan Savanna region should apply NPK 15:15:15 fertilizer at a rate of 60:30:30:kg/ha for optimal growth and yield of carrot varieties.