Calibration of Soil Phosphorus Test for Upland Rice Grown on Typic Kandiudox, Way Pangubuan, Lampung. j Trop. Soils [Internet]. 2019 Jan. 25 [cited 2025 Oct. 30];23(2):81-9. Available from: https://journal.unila.ac.id/index.php/tropicalsoil/article/view/267