“The Role of Spent Oyster Substrate Supplemented With Biological Factors and Spraying With Spent Substrate Extract on Some Vegetative Growth Characteristics of Cowpea (Vigna Unguiculata L.)”. Euphrates journal of agricultural science 18, no. 3 (September 30, 2026). Accessed November 3, 2026. https://ejs-agri.com/index.php/EJAS/article/view/431.