Jurnal Ilmiah Perikanan dan Kelautan Vol. 3 No. 2, November 2011 157 PENGARUH PENAMBAHAN PUPUK BINTIL AKAR KACANG TANAH SEBAGAI SUMBER NITROGEN DAN FOSFOR TERHADAP POPULASI Chlorella sp. THE EFFECT OF ADDITION FERTILIZER ROOTS NODULE PEANUT AS A SOURCE OF NITROGEN AND PHOSPHORUS TO THE POPULATION OF Chlorella SP. Rr. Juni Triastuti, A. Shofy Mubarak dan Likanimasayu Prabandari Fakultas Perikanan dan Kelautan Universitas Airlangga Kampus C Mulyorejo - Surabaya, 60115 Telp. 031-5911451 Abstract Chlorella sp. is one natural food that widely used in hatchery fish, shrimp and oyster. The availability of natural food is a factor that has an important role in farming activities. Culture of Chlorella sp. generally use technical fertilizer (Walne) where nitrogen and phosporus in Walne beginning chemist fertilizer the price expensive. One source of nitrogen and phosphorus naturally obtained from the roots of peanuts. The root nodules contained peanut-containing nodule bacteria Rhizobium are able to bind nitrogen from the air element. By doing immersion can be obtained nutrients to the roots of peanuts are nitrogen and phosphorus that is soluble in water. So that the root nodules of peanuts can be used as a source of nitrogen and phosphorus to increase the population of Chlorella sp. The purpose of this study was to determine the effect of the addition of fertilizer and the concentration of peanut root nodules as a source of nitrogen and phosphorus to the population of Chlorella sp. The research was conducted in June until July in the Laboratory of Education Faculty of Fisheries and Marine Fisheries, Airlangga University, Surabaya. The study design used was Completely Randomized Design (CRD). Materials tested in this study was Chlorella sp. whereas fertilizer used is the root nodules of peanut fertilizer and manure Walne. The concentration of the addition of fertilizer peanut nodule is the treatment A (2.25 ppm), treatment B (4.5 ppm), treatment C (9 ppm) and treatment D (18 ppm). Control treatments using fertilizer Walne 0.5 ml/l (control 1) and 1 ml/l (control 2). The main parameter is observed population density, while supporters of the observed parameter is the measurement of temperature, pH and salinity. The results showed that the addition of fertilizer peanut nodule as a source nitrogen and phosporus influence population of Chlorella sp. The addition of fertilizer best peanut nodule is the treatment B of 1,43755x10 6 cells/ml on the third day. Water quality parameters during the study remained within the tolerance limit for the growth of Chlorella sp. is pH 7-8, room temperature 29-32 0 C range, salinity range between 28-40 ppt and water temperature ranges between 28-30 0 C. Keywords : Chlorella sp., root nodule peanut, nitrogen and phosphorus Pendahuluan Chlorella sp. merupakan salah satu pakan alami yang banyak digunakan secara luas terutama di panti-panti pembenihan ikan, udang dan kekerangan (Ukeles, 1971; Ryther & Goldman, 1975; Fujita, 1979; Kadowaki et al., 1980; De pauw & Persoone, 1988; James & Rezeq 1988 dalam Panggabean dan Sutomo, 1995). Pemenuhan ketersediaan Chlorella sp. sebagai pakan alami perlu ditingkatan dengan cara memenuhi kebutuhan makro dan mikro nutrien. Isnansetyo dan Kurniastuty (1995) menyatakan bahwa kultur fitoplankton membutuhkan berbagai macam unsur hara baik unsur hara makro misalnya N, P, K, S, Si, Na, Ca maupun unsur hara mikro misalnya Fe, Zn, Mn, Cu, Mg, Co, Mo, B. Nutrien yang dibutuhkan untuk pertumbuhan Chlorella sp. yaitu makro dan mikro nutrien. Nutrien tersebut meliputi N, P, Mg, S, K, Ca, Fe, Mn, Zn, dan Cu (Eyster, 1978). Kultur Chlorella sp. pada umumnya menggunakan pupuk teknis yaitu pupuk Walne dimana konsentrasi unsur makro nutrien pupuk teknis belum mencukupi batas optimal kebutuhan Chlorella sp. Kandungan nitrogen dan fosfor pupuk Walne adalah 0,016 g/l dan 0,004 g/l sedangkan kebutuhan nitrogen dan fosfor Chlorella sp. adalah 0,7-0,14 g/l dan 0,62-0,015 g/l (Eyster, 1978).