Evaluating Fertilizer Application Rates for Giant Gourami, Osphronemus goramy, Ponds

Abstract

Twelve, 400‐m2 earthen ponds at Walailak University, Thailand, were used to investigate the effects of fertilizer application rates on water quality, bottom soil, and production of giant gourami, Osphronemus goramy. Fertilizer rates of 0, 6, 9, and 12 kg N plus 0, 3, 4.5, and 6 kg P2O5 /ha (N:P2O5 = 2:1) applied at 3‐wk intervals were replicated three times in a completely randomized design. Ammonium phosphate and ammonium sulfate were sources of nitrogen and phosphorus. Fish averaged 8.8 g and were stocked at 1 fish/m2. The highest final weight, growth rate, and net production of giant gourami were achieved with 9 kg N plus 4.5 kg P2O5/ha. Chlorophyll a concentration was correlated with total nitrogen concentration (R2 = 0.574; P < 0.05) and total phosphorus concentration (R2 = 0.600, P < 0.05). Fish production and chlorophyll a concentration were also correlated (0.826; P < 0.05). Chlorophyll a concentration and fish production declined at total hardness concentrations above about 50 mg/L – likely from precipitation of fertilizer phosphorus as calcium phosphate. Pond bottom soil properties did not change in relationship to fertilizer rate.

Nutrient budgets in a small-scale freshwater fish pond system in Indonesia

“…In our system, we used organic fertilizer instead of chemicals and water renewal was about 4-11% d -1 during the fish production cycle. These differences likely explain the lower primary productivity observed in our ponds compared with Thai ponds (Pengseng and Boyd, 2011).…”

“…Aquaculture of giant gourami O. goramy in Indonesia is a very old practice (Cuvier and Valenciennes, 1831). Many small-scale Asian fish farmers produce giant gourami in fertilized ponds to limit the use of high-priced commercial pellets (Pengseng and Boyd, 2011). In such systems, giant gourami is traditionally fed a combination of local plants such as giant taro (Alocasia macrorrhizos), supplemented with commercial pellets in varying proportions (Aubin et al, 2017).…”

“…This species can breathe atmospheric air and can be reared in heavily fertilized ponds (Pengseng and Boyd, 2011), rich in phytoplankton and for which the dramatic variation in dissolved oxygen can be harmful for other fish species produced locally in earthen ponds, such as the Nile tilapia Oreochromis niloticus or the common carp Cyprinus carpio (Philips et al, 2015). Considering chlorophyll a as a proxy for the level of fertilization in ponds, although there are significant variations during the production cycle, the mean values between 169 and 446 µg L -1 of chlorophyll a in our ponds are well below those (up to 85.8 mg L -1 ) obtained in giant gourami production ponds in Thailand (Pengseng and Boyd, 2011) despite fertilization rates about 10 times lower (maximum of 60 kg N ha -1 and 30 kg P ha -1 applied during a 120 d production cycle using inorganic fertilizers) than those used in our experiment.…”

Effects of shading, fertilization and snail grazing on the productivity of the water fern Azolla filiculoides for tropical freshwater aquaculture

“…In experimental conditions, 2 to 10 μmol L -1 P are reported for the sustainable growth of Azolla (Subudhi and Watanabe, 1981;Kitoh and Shiomi, 1991;Temmink et al, 2018), but field observations suggest that higher concentrations are necessary (10 to 33 μmol L -1 , Sadeghi et al, 2013). Based on this information, P may be limiting for Azolla production even in fertilized ponds used for fish production, where P concentrations are usually between 1-17 μmol L -1 (Green and Boyd, 1995;Pengseng and Boyd, 2011;Pouil et al, 2019). In addition, temperature and light intensity are important climate variables determining Azolla growth rates in the field (Sadeghi et al, 2013).…”

The complete mitochondrial genome ofOsphronemus goramy(Perciformes: Osphronemidae)

“…The Osphronemus goramy (giant gourami) is a commercially important freshwater fish belonging to the family Osphronemidae, which was originated from Indonesian and has been introduced into other Asian countries (Pengseng & Boyd 2011;Azrita 2015). On account of its large size, beautiful appearance, tasty meat and easiness to conduct breeding operation, it is now considered to be an important species with high economic value (Bhimachar et al 1944).…”