Fertilization dosage`s effects on the growth of phyto and zooplankton communities

Abstract

This paper deals with the characterization of 8 ponds submitted to different rates of fertilization at the Pindamonhangaba Fish Culture Experimental Station. Samplings were carried out diary or at weekly intervals (from October/1989 to September/1990) for temperature, pH, dissolved oxygen, phytoplankton (plankton net of 40 µm mesh size) and zooplankton (plankton net of 60 µm mesh size) determinations. The levels of fertilization were: 100 g/m².month of cow manure and 100 g/m².month chicken manure + [superphosphate (60%) + ammonium sulphate (40%)] in the following quantities: 6.2; 4.6 and 3.1 g/m².month. It was observed that phytoplankton community was dominated by Chlorophyceae and the zooplankton community, by Rotifera. The abundance of phyto and zooplanktonic species differed in different treatments. The species diversity and abundance increased with an increase in temperature and an increase in the quantity of both manures. Cyanophyceae blooms occurred periodically. Better resuIts were: manure (cow manure and chicken manure) + 6.2 and 4.6 g/m².month.