Auliadesti, Vivin. “Pengaruh Penambahan Biochar Kulit Kopi Dan Abu Valkanis Dalam Memperbaiki Sifat Kimia Ultisol”. Journal Arunasita 2, no. 1 (February 7, 2025): 1–13. Accessed July 5, 2025. https://ejournal.arunasita.com/jasita/article/view/7.