Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil Column Method. j Trop. Soils [Internet]. 2018 Apr. 9 [cited 2025 Nov. 15];15(1):11-8. Available from: https://journal.unila.ac.id/index.php/tropicalsoil/article/view/22