Aquaponic Production of Tilapia and Basil: Comparing a Batch and Staggered Cropping System

Abstract

Aquaponics is the combined culture of fish and hydroponic plants in recirculating systems. Aquaculture effluent provides most of the nutrients required by plants if the optimum ratio between daily feed input and plant growing area is maintained. An experiment was conducted in an outdoor, commercial-scale aquaponic system on 0.05 ha of land in the tropics. The objectives were to determine the production of tilapia and basil using batch and staggered cropping systems, compare aquaponics with field crop production and evaluate the ratio of feed input to plant growing area. The projected annual production of tilapia was 4.37 t. The mean yield of basil was 2.0, 1.8 and 0.6 kg/m 2 using batch, staggered and field cropping systems, respectively. Projected annual production of the system was 5.0 t of basil with staggered production. Nutrient deficiency symptoms appeared only in the batch-cultured basil. The feed input ratio was 81.4 g/day/m 2 for batch culture and 99.6 g/day/m 2 for staggered production. Staggered production moderated the uptake of nutrients. Basil production is sustainable in an aquaponic system with a feed input ratio of 99.6 g/day/m 2 and a staggered cropping system. several types of lettuce (Lactuca sativa). The present study was conducted to determine the production of tilapia and basil (Ocimum basilicum 'Genovese') in this aquaponic system, using batch and staggered cropping systems, compare it to field crop production and evaluate the ratio of feed input to plant growing area. MATERIALS AND METHODS The UVI aquaponic system was situated outdoors and consisted of four fish rearing tanks (7.8 m 3 each), two cylindro-conical clarifiers (3.8 m 3 each), four filter tanks (0.7 m 3 each) containing orchard netting, one degassing tank (0.7 m 3), six raft hydroponic tanks (each of which was 11.4 m 3 and measured 30.5 m by 1.2 m by 30 cm: total hydroponic growing area was 214 m 2), one sump (0.6 m 3) and one base addition tank (0.2 m 3) (Fig. 1). Total system water volume was 110 m 3. The fish rearing and hydroponic tanks were each aerated by separate 1-hp blowers and air stones. A ½-hp water pump circulated water at a rate of 378 L/min. Average retention time was 1.4 hours in the fish rearing tanks and 3.0 hours in the hydroponic tanks. With the exception of the hydroponic tanks, all other tanks were situated under an opaque canopy. The production unit occupied 0.05 ha of land. Prior to initiating the experiment the fish rearing tanks were in continuous operation for the production of Nile tilapia (Oreochromis niloticus) or red tilapia (Oreochromis sp.). Fish production cycles were 24 weeks. Production within the four rearing tanks was staggered so that one tank was harvested every 6 weeks. Nile tilapia fingerlings were stocked at 77 fish/m 3 while red tilapia fingerlings were stocked at 154 fish/m 3. Fingerlings averaged 70 g. The fish were fed three times daily ad libitum for 30 minutes with a complete diet of floating pellets containing 32% protein. Within 2 weeks of initiating the first basil trial usin...

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“…High plant growth in T2 showed the best consumption of nitrate-N by plants; thus, the lowest nitrate-N value was noticed in the T2. When compared to Rakocy et al (2004), low nitrate-N value was found in this experiment; however, nutrient deficiency symptoms were not observed in plants. Nitrate-N is relatively nontoxic to fish and has no health hazards, except above 90 mg/L (Stone & Thomforde, 2004).…”

“…Tilapia and vegetable production in the UVI aquaponic system developed by Rakocy, Bailey, Shultz, and Thoman (2004) showed that 0.4 mg/L nitrite-N value is appropriate. In the present experiment, control showed the highest value (0.071 mg/L and others were very less when compared with the results obtained by Rakocy et al (2004). Comparatively high nitrate-N value was found, in control and the lowest value was obtained in T2 when comparing the treatments.…”

Comparison of Two Harvest Methods for Lettuce Production in an Aquaponic System

“…Not all crops can be harvested by the CC method in FTS. Other vegetables such as Swiss chard, herbs and cilantro would also be good candidates for FTS production using the CC method combined with the OD method (Buzby, Waterland, Semmens, & Lin, 2016a;Buzby et al, 2016b;Rakocy, Bailey, Shultz, & Thoman, 2004). Note.…”

Hydroponic systems and water management in aquaponics: a review

“…Aquaponics (AP), the combination of hydroponics and recirculating aquaculture (Rakocy et al, 2003) is a promising solution for the negative environmental impacts typically associated with intensive fish and crop production. In these integrated systems, nutrients that are excreted by the fish or generated by microbial activity (Munguia-Fragozo et al, 2015;Zou et al, 2016a) are absorbed by hydroponically cultured plants, thus treating the water before it is recycled to the fish tank (Endut et al, 2009;Tyson et al, 2011;Nichols and Savidov, 2012;Medina et al, 2016;Nuwansi et al, 2016).…”