Musa, U.T. and Yusuf, M. 2026. Optimizing NPK Fertilizer Use to Improve Yield and Protein Content of Cowpea [Vigna unguiculata (L.) Walp]: A Review. Agricultura Scientia. 23, 1 (Jul. 2026), 29–46. DOI:https://doi.org/10.18690/agricsci.23.1.4.