Vol. 3, Issue 6 (2016)
Impacts of different fertilizers on production of fishes in polyculture system
Author(s): Parvez Chowdhury, Jakir Hossen, Mst. Khadiza Khatun, Md. Shahadat Hossain, Md. Moshiur Rahman
Abstract: The experiment was conducted to determine the impacts of different fertilizers on production of fishes in polyculture system for three months. There were 3 treatments with two replications under each treatment and each pond was stocked with a total of 80 fish fry. Pond nos. 2 and 5 were under the treatment-I (TSP-90g per decimal fortnightly), pond nos. 1 and 4 were under the treatment-II (urea-60g and TSP-90g per decimal fortnightly) and pond nos. 3 and 6 were under the treatment-III (urea 60g and cowdung 1kg per decimal fortnightly). During experimental period, the ranges of water temperature (21.82 to 27.69 ºC), transparency (28.00 to 36.00 cm), dissolved oxygen (6.00 to 8.30 mg/L), pH (7.00 to 7.90), total alkalinity (142.00 to 205.00 mg/L), free CO2 (2.00 to 4.00 mg/L), phosphate-phosphorus (1.20 to 2.30 mg/L), and nitrate-nitrogen (3.20 to 4.00 mg/L) were within the productive range and more or less similar in all the ponds under three treatments. Mean phytoplankton and zooplankton densities under treatment-I, II and III were 73.52±3.12 (× 103) cells/L,10.62±0.95 (× 103) cells/L and 75.79±2.39 (× 103) cells/L, 11.50±1.47 (× 103) cells/L and 74.41±7.87 (×103) cells/L, 10.17±1.56 (× 103) cells/L, respectively. The net productions of fish of the ponds under treatment-I, II and III were 1.041 ton/ha/yr, 1.425 ton/ha/yr and 1.191 ton/ha/yr, respectively. So, the use of urea 60g and TSP 90g per decimal (under treatment-II) might be considered the best among the three treatments.