Impact of physico-chemistry of water on the planktonic biota and fish yields in poultry manure fertilized ponds
2000
Hayat, S. (Fisheries Research and Training Inst., Lahore (Pakistan)) | Javed, M. | Hanif, K.
A project spread over a period of one year has been conducted. Two levels of nitrogen, i.e.; 0.15 and 0.17 N/1008 of fish weight daily, from poultry droppings, have been tested against control (without additives) to assess the water quality of fish pond under integrated culture system. Under treatment-1 (0.15% N) 82.05 percent variations in planktonic productivity were recorded due to phosphorus and electrical conductivity. In treatment-2 (0.17% N) combined contributions of nitrates, electrical conductivity and pH remained 85.50 percent towards planktonic productivity. However, under the influence of treatment-3 (control without additives) electrical conductivity and total alkalinity caused 90.10 percent variations in planktonic productivity of the pond. The net yields under all the treatments were affected significantly by water temperature as it caused 67.04, 84.80 and 84.60 percent variations under 0.15 and 0.17% nitrogen and control regime, respectively. However, electrical conductivity (with positive Regression Coefficient) appeared to be another variable, along with water temperature that caused 84.71 and 92.83 % variations in fish yields under T1, (0.15% N) and T2 (0.17%) respectively. Under T3 (control) the combined effect of electrical conductivity and total alkalinity remained 90.10 percent towards fish yield of the treatment.
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