Utilization of Coal Bottom Ash and Cattle Manure as Soil Ameliorant on Acid Soil and Its Effect on Heavy Metal Content in Mustard (Brassica juncea). j Trop. Soils [Internet]. 2017 May 1 [cited 2025 Nov. 3];22(2):87-95. Available from: https://journal.unila.ac.id/index.php/tropicalsoil/article/view/69