Effects of rock phosphate amended with poultry manure on soil available p and yield of maize and cowpea. International Journal of Manures and Fertilizers, [S. l.], v. 9, n. 1, p. 1–5, 2021. Disponível em: https://www.ijpp.org/journal/index.php/ijmf/article/view/94. Acesso em: 5 apr. 2026.