Harja Y, Yusnaini S, Prasetyo D, Lumbanraja J. The Effect of Biochar and Chicken Manure on Earthworm Population and Biomass in Corn Plantation(Zea mays L.). J. Trop. Upland Res. [Internet]. 2023May12 [cited 2026Jun.12];5(1):15-0. Available from: https://jtur.lppm.unila.ac.id.121-50-32-50.cpanel.site/index.php/jtur/article/view/138