Effect of different fertilizers on the growth of duckweed (Lemna minor) as aquatic plant resources utilization in sustaining Red Tilapia (Oreochromis niloticus) culture

Abstract

Duckweed (Lemna minor) is one of the smallest floating aquatic plants in the world. This plant is potentially important in the aquaculture feed industry since aquaculture feed is the major operational cost in fish production. This 37-days study was done to see the effect of different fertilizers; (goat manure, chicken manure and organic fertilizer) at the same concentration of 2g/L on duckweed growth. Tap water without fertilizer was used as a control. Water parameters such as pH, temperature, nitrate, phosphate, and ammonia were observed. The result of duckweed growth rate after 37 days in goat manure fertilizer (0.76 grams/day) is the highest followed by chicken manure fertilizer (0.15 grams/day), organic fertilizer (0.02977 grams/day) and the control (-0.00 133 grams/day). The number of the duckweed at the end of experiment by using the goat manure fertilizer is higher which is 489 units, followed by chicken manure fertilizer (179 units), organic fertilizer (64 units) and control (22 unit). Treatment of goat manure fertilizer has a high concentration of nitrate 1.99 ppm, ammonia 2.69 ppm and available phosphate 7.71 ppm which suitability for duckweed growth. Since duckweed is easy to be cultured, this natural resource of aquatic plants can be produced commercially for Red Tilapia ( Oreochromis niloticus) farm.