Cowpea Yield as Affected by Level and Time of Mineral Phosphorus Fertilizer Application in the Guinea Savanna Agro-Ecological Zone of Ghana. Global Journal of Science Frontier Research, [S. l.], v. 14, n. 36, p. 13–17, 2014. Disponível em: https://journalofscience.org/index.php/GJSFR/article/view/. Acesso em: 23 oct. 2026.