Growth and Yield Response of Carrot (Daucus carota L.) to Integrated Nutrient Management in the Forest–Savannah Transitional Zone of Ghana

Abstract

Carrot is an important root vegetable valued for its nutritional and economic benefits; however, achieving optimal growth and yield in the Forest–Savannah transitional zone of Ghana remains a challenge due to variable soil fertility and limited nutrient availability. In view of this, two field experiments were conducted from September 2021 to December 2021 and from April 2022 to July 2022 at the multipurpose crop nursery field of Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development, Mampong Campus, to assess the effects of integrated nutrient management of organic and inorganic fertilizers on growth and yield of carrot (Daucus carota L.) using a randomized complete block design (6 treatments x 4 replicates). Nutrient regimes were: control (no fertilizer), full NPK (300 kg ha⁻¹ 15–15–15), full chicken manure (20 t ha⁻¹), and three blends (¾, ½, ¼ NPK with complementary CM). INM significantly increased plant height, canopy width, biomass, and marketable root yield relative to control (α = 0.05). The best treatment differed by season: full CM produced the highest total yield in 2021 (13.06 t ha⁻¹), while ¼ NPK + ¾ CM led in 2022 (14.37 t ha⁻¹). Across seasons, yield correlated positively with marketable root number, dry root weight, root length, and diameter. These results indicate that combining mineral NPK with chicken manure reliably improves carrot performance, with the optimal ratio influenced by seasonal conditions. We recommend full CM or ¼ NPK + ¾ CM as farmer-ready options, while future work should include economic analysis to guide adoption.