Abstract:
Phytoplankton is a very important microorganisms in pond, it has a function as primary
producer, natural fish food and as supporting water quality parameters. Phytoplankton
growth could be supported by adding fertilizer. One of the best fertilizer that could be used
in the swampy area is bokashi manure from chicken wastes and EM4. The research was
conducted from July – August 2010 in water quality laboratory, Fisheries and Marine
Faculty, Riau University. Research method used in this research is complete randomly
design with one factor four stages treatment and three replications. As stages treatment in
this research is N, P, K fertilizer with dose of 2.25 g/m2 (P0), bokashi fertilizer 32.66 g/m2
(P1), 65.32 g/m2 (P2) and 97.98 g/m2 (P3). From the study, it is invented 3 classes of
phytoplankton Chlorophyceae (8 spesies), Cyanophyceae (6 spesies) and Bacillariophyceae
(4 spesies), the high abundance is Ulothrix sp. Regression analysis, shown that is has
positive correlation between doses of bokashi fertilizer with phytoplankton abundance. The
best result of bokashi fertilizer is 97.98 g/m2 (P3) with phytoplankton abundance of 2208
ind/l. Soil and water quality are in good range for phytoplankton growth, such as : soil
nitrate 0.4810-1.0264 ppm, soil phosphore 0.2796-1.6967 ppm, organic matter 7.199-
14.710 %, pH 6-8, temperature 24-310C, dissolved oxygen 3.8-5.6 mg/l, nitrate 0.5291-
1.9598 ppm, orthophosphate 0.3418-1.2449 ppm, hardness 60-119 ppm, carbondioxide
3.07-6.05 mg/l and turbidity 7-54 NTU.
