Kesuburan lahan tambak merupakan hal yang paling penting dalam budidaya udang untuk mempertahankan tingkat produksi dan memastikan pengembangan usaha budidaya tambak yang lebih baik. Penelitian ini bertujuan untuk mengetahui tingkat kesuburan tanah tambak kota Tarakan Provinsi Kalimantan Utara. Peneltian ini menggunakan metode wawancara dan survey lapangan yang dilakukan pada 6 titik lokasi pertambakan yang berada di Tarakan (Tarakan Utara, Tarakan Barat, dan Tarakan Timur). Kualitas sifat fisika-kimia tanah tambak yang diukur meliputi: KTK, C-Organik, P205 (HCI,25%) dan K20 (HCI, 25%. Sampel tanah tambak diambil pada lapisan topsoil (0-5 cm) pengambilan sampel tanah dengan menggunakan Spatula kemudian sampel tanah dimasukan ke dalam plastik stand up pauch dan disimpan dalam cool box. Hasil penelitian menunjukan kondisi tanah tambak dikota Tarakan umumnya ada tambak tua yang nilai kesuburan tanah tambak yang sudah mulai berkurang, dari ketiga sample tanah tambak yang paling subur tanah tambaknya terdapat pada tanah tambak daerah Tarakan Barat dengan nilai kandungan tanah (C Organik 1,09 – 1,52), (P₂O₅ 9,35 – 11,92), (K₂O 8,84 – 19,28) dan (KTK 11,73 – 9,28).
Kata kunci: Tambak Tradisional, Kesuburan Tambak

North Kalimantan has vast natural resources, especially in the fisheries sector with promising prospects and can help regional development so that in the development of fisheries, aquaculture can make an increasingly large contribotions to effort to increase fish production. The soil fertility of the pound is the most important thing is shrimp farming go maintain production levels and ensure the development of a better pond farming business. The study aimed to determine the level of soil fertility in the ponds of Tarakan City, North Kalimantan this research used interview methods and field surveys conducted at a 6 points of the physicochemical properties of pond soils that were measured included CEC, C-Organik, P2O5, and K2O. pond soil smplels were taken from the topsoil layer 0-5 cm. soil sampling was carried 2 out using a spatula, then the soil samples were put into a stand up pouch plastic and stored in a cool box. The results showed that the condition of pond soil in Tarakan City was generally old ponds where the fertility value of pond soil had begun to decrease. Based on the three existing pond soil samples, it showed that fertile pond soil was found in the West Tarakan area whit soil organic C content value of around 1.09 – 1.52%, P2O5 around 9.35 – 11.92%, K2O around 8.84 – 19.28 Ppm and CEC around 11.73 – 9.28 Mg. Keywords: Fertility, soil, Traditional Pounds