UTTAR PRADESH JOURNAL OF ZOOLOGY

This study assessed the effects of graded dietary duckweed (Lemna minor) inclusion on selected soil and water quality parameters in grass carp (Ctenopharyngodon idella) culture ponds. The 180-day feeding trial comprised a control and three dietary treatments containing 5%, 10%, and 20% duckweed, designated T1, T2, and T3, respectively. Two hundred fingerlings were distributed among the experimental ponds and fed at 5% of body weight twice daily. Water temperature, pH, alkalinity, dissolved oxygen, and total dissolved solids were monitored, while pond-soil pH, nitrogen, organic carbon, potassium, and phosphorus were also assessed. Water temperature ranged from 24.7 to 25.7°C, pH from 7.9 to 8.5, alkalinity from 110 to 200 mg/L, and dissolved oxygen from 5.0 to 8.0 mg/L. Total dissolved solids ranged from 430 to 608 mg/L. Soil pH varied from 7.4 to 8.1, while the measured soil nutrient values showed moderate differences among the control and treatment groups. Across the reported environmental measurements, dietary duckweed inclusion was not associated with clear deterioration in the selected pond-water parameters. However, the available data do not establish treatment-related effects on pond soil, fish growth, feed efficiency, survival, or profitability because the replication, statistical analysis, and performance data are incompletely reported. Further replicated field evaluation is therefore required before larger-scale adoption.