Kedir, Mohammed. “A Review of Combined Use of Biochar With Nitrogen Fertilizer As an Instrument for Improving Maize Yield and Soil Fertility”. Discoveries in Agriculture and Food Sciences 10, no. 4 (April 19, 2023): 32–38. Accessed May 16, 2024. https://journals.scholarpublishing.org/index.php/TNC/article/view/14379.