부산대학교 도서관

Inorganic aquaculture system, Napier grass (Pennisetum purpureum) provides the use of a holistic farming system based on partnership with nature. Therefore, in this study, we assessed the water quality parameter, growth performance parameter, and production of carp fishes in a polyculture system feeding Napier grass, and analyzed the benefit-cost ratio of grass carp (Ctenopharyngodon idella) and other carp fishes production using Napier grass under different stocking density with three treatments (T1, T2, T3) each with three replications following a randomized complete block design from July 2018 to June 2019. Stocking density was 1250 fish ha-1 (T1), 2500 fish ha-1 (T2), and 3750 fish ha-1 (T3) for grass carp. Catla (Catla catla), common carp (Cyprinus carpio) and mirror carp (Cyprinus carpio carpio) were stocked along with grass carp at the rate of 1250 fish ha-1 for all treatments. Water quality parameters such as temperature, dissolved oxygen, pH, nitrite, nitrate, phosphate, and ammonia were within the suitable range for culture. No significant differences (p>0.05) were found among the treatments. The gross production was significantly higher in T3 (6.1-ton ha-1 year-1) followed by T2 (3.9-ton ha-1 year-1) and T1 (1.9-ton ha-1 year-1). The cost-benefit analysis revealed that the net income significantly varied (p<0.05) among three treatments (659.0, 2569.8, and 5031.5 USD ha-1 year-1 in T1, T2 and T3, respectively). From the economic point of view, better production and income of grass carp, catla, common carp, and mirror carp were estimated in T3 as the stocking density of grass carp was higher in T3 resulting in higher feces production caused higher plankton production in T3 ponds. The results imply that Napier grass can be used as a food source to replace commercial fish feed in the regular diet of grass carp without compromising the growth of fish and the potential for safe use in aquaculture. [ABSTRACT FROM AUTHOR]