FERMENTED COMPOST APPLICATION IN EARTHEN PONDS AND THE RESULTED EFFECT ON WATER-QUALITY, PHYTOPLANKTON POPULATION AND FISH YIELD

FERMENTED COMPOST APPLICATION IN EARTHEN PONDS AND THE RESULTED EFFECT ON WATER-QUALITY, PHYTOPLANKTON POPULATION

AND FISH YIELD

Amr M. Alnagaawy¹
and Ayman A. Ammar²

¹Limnology Dept.; ²Fish production and aquaculture systems Dept., Central Lab for Aquaculture Research (CLAR), ARC.

Received 25/ 2/ 2010 Accepted 1/ 4/ 2010

Abstract

Compost had been used as initiating dose in earthen fish-ponds. Different compost application techniques had been tested for the optimum one as reflected on water quality as well as phytoplankton production. Six different techniques of compost were applied as follow: without compost, compost without fermentation, compost fermented for one month outside the pond, compost fermented for two months outside the pond, compost fermented for one month inside the pond and compost fermented for two months inside the pond. Highest electric conductivity, salinity and total dissolved solids were obtained in compost fermented for 2 months outside the pond treatment (2 O). Highest orthophosphate, chlorophyll “a” concentrations as well as total phytoplankton count were detected in two months inside pond fermented compost treatment and then in compost without fermentation treatment. Lowest total alkalinity and total hardness were recorded in 2 months inside the pond (2 IN) treatment. In spite of the highest fish yield was obtained in 1 month outside the pond (1 O) treatment, but the highest percentage of the sum. of super&1^st grades of fish size was obtained in 2 IN treatment. An initial single dose of fermented compost highly recommended, when compost was fermented for 2 months inside the pond.