Aktivitas fosfatase dan produksi asam organik di rhizosfer dan hifosfer bibit kelapa sawit bermikoriza *) Phosphatase activity and organic acid production in rhizosphere and hyphosphere of mycorrhizal oil palm seedling. (2016). E-Journal Menara Perkebunan, 71(2). https://doi.org/10.22302/iribb.jur.mp.v71i2.164