Khusrizal, Basyaruddin, Diapari Siregar, Candra Syahputra. The Effectiveness of Heated and Acidified Volcanic Ash on Exchangable K, Ca, Mg of Soil, and Kcl Efficiency for Growth and Yield of Corn (Zea Mays L). IJAST [Internet]. 2020May16 [cited 2026Sep.30];29(7):1664 -174. Available from: http://sersc.org/journals/index.php/IJAST/article/view/16252