Jalal HN, Haloul RA. The effect of biochar and extract of organic fertilizer on the readiness of certain elements in the soil. JKAS [Internet]. 2023 Sep. 12 [cited 2024 Dec. 14];10(3):190-9. Available from: https://mail.journals.uokerbala.edu.iq/index.php/Agriculture/article/view/1252