The use of retorted oil shale as urea coating does not modify chemical parameters of free-drained soil solution. Research, Society and Development, [S. l.], v. 11, n. 9, p. e7811931521, 2022. DOI: 10.33448/rsd-v11i9.31521. Disponível em: https://rsdjournal.org/rsd/article/view/31521. Acesso em: 5 dec. 2025.