Simanjuntak, Riki Rikardo, Saroha Manurung, and Aulia Juanda Djaingsastro. 2026. “Analisis Kandungan N, P, K, Dan C-Organik Pada Tanah Datar Dan Tanah Miring Di Kebun Silau Dunia Afdeling III PT Perkebunan Nusantara IV Regional I”. Ranah Research : Journal of Multidisciplinary Research and Development 8 (3), 1951-61. https://doi.org/10.38035/rrj.v8i3.2112.