Fosfor merupakan unsur hara esensial bagi tanaman agar dapat tumbuh secara optimal. Ketersbahan organik fosfor pada sedimen di kawasan mangrove berfungsi untuk membantu berlangsungnya proses fotosinstesis, penggunaan gula dan pati oleh tanaman. Rendahnya kandungan fosfor pada sedimen berdampak bagi terhambatnya pertumbuhan tanaman dikawasan mangrove. Tujuan dari penelitian ini adalah untuk meguji kandungan fosfor total pada sedimen berdasarkan perbedaan kedalaman di Kawasan Konservasi Mangrove dan Kepiting Kelurahan Pamusian Kota Tarakan. Penelitian ini dilaksanakan pada bulan April sampai dengan bulan Juni 2023. Metode dalam penelitian ini adalah Metode deskriptif kuantitatif dengan mendeskripsikan kandungan Fosfor (P) pada sedimen berdasarkan perbedaan kedalaman pada setiap stasiun sampling. Pengambilan sampel sedimen dilakukan pada tiga Stasiun berbeda yaitu Stasiun 1 dekat daerah aliran sungai, Stasiun 2 dekat menara pengawas dan Stasiun 3 dekat daerah pemukiman warga. Pengujian sampel sedimen dilakukan di Laboratorium Ilmu Tanah Fakultas Pertanian Universitas Borneo Tarakan. Hasil penelitian ini diperoleh kandungan Fosfor (P) pada kedalaman 10 cm berkisar 12,44 mg/L- 14, 22 mg/L, kedalaman 20 cm berkisar 12, 59 mg/L – 17,87 mg/L dan kedalaman 30 cm berkisar 12, 44 mg/L – 13, 51 mg/L.

Kata Kunci: Fosfor, Kedalaman, Mangrove, Pamusian, Sedimen

Phosphorus is an essential nutrient for plants to grow optimally. The availability of organic phosphorus in sediments in mangrove areas functions to help the process of photosynthesis and the use of sugar and starch by plants. The low content of phosphorus in sediments has an impact on inhibiting plant growth in mangrove areas. The purpose of this study was to examine the total phosphorus content in sediments based on differences in depth in the mangrove and crab conservation area of Pamusian Village, Tarakan City. This research was conducted from April to June 2023. The method in this study was the quantitative descriptive method, which described the content of phosphorus (P) in sediments based on differences in depth at each sampling station. Sediment sampling was carried out at three different stations, namely Station 1 near the watershed, Station 2 near the watchtower, and Station 3 near residential areas. Sediment sample testing was conducted at the Soil Science Laboratory, Faculty of Agriculture, Borneo University of Tarakan. The results of this study showed that phosphorus (P) content at a depth of 10 cm ranged from 12.44 mg/L to 14,22 mg/L; a depth of 20 cm ranged from 12,59 mg/L to 17.87 mg/L; and a depth of 30 cm ranged from 12,44 mg/L to 13,51 mg/L. Keywords: Phosphorus, Depth, Mangrove, Pamusian, Sediment