A Comparison of Three Different Hydroponic Sub-systems (gravel bed, floating and nutrient film technique) in an Aquaponic Test System
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Murray Cod, Maccullochella peelii peelii (Mitchell), and Green Oak lettuce, Lactuca sativa, were used to test for differences between three hydroponic subsystems, Gravel Bed, Floating Raft and Nutrient Film Technique (NFT), in a freshwater Aquaponic test system, where plant nutrients were supplied from fish wastes while plants stripped nutrients from the waste water before it was returned to the fish. The Murray Cod had FCR's and biomass gains that were statistically identical in all systems. Lettuce yields were good, and in terms of biomass gain and yield, followed the relationship Gravel bed > Floating > NFT, with significant differences seen between all treatments. The NFT treatment was significantly less efficient than the other two treatments in terms of nitrate removal (20% less efficient), whilst no significant difference was seen between any test treatments in terms of phosphate removal. In terms of dissolved oxygen, water replacement and conductivity, no significant differences were observed between any test treatments. Overall, results suggest that NFT hydroponic sub-systems are less efficient at both removing nutrients from fish culture water and producing plant biomass or yield than Gravel bed or Floating hydroponic sub-systems in an Aquaponic context. Aquaponic system designers need to take these differences into account when designing hydroponic components within aquaponic systems.
KeywordsAquaponic Hydroponic NFT Biological nutrient removal Wastewater Murray Cod Nitrate Phosphate
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This research was partially funded by the Australian Federal Governments Rural Industry Research and Development Corporation (RIRDC). The authors also wish to thank Boomaroo Nurseries (Lara, Victoria, Australia) for the provision of the many lettuce seedlings used to complete this study and Dr. Brett Ingram of the Victorian Institute of Marine and Freshwater Research for his invaluable knowledge of Murray Cod culture.
- Adler PR, Harper JK, Takeda F, Wade EM, Summerfelt ST (2000a) Economic evaluation of hydroponics and other treatment options for phosphorous removal in aquaculture effluent. Hortic Sci 35:993–999Google Scholar
- Adler PR, Harper JK, Wade EM, Takeda F, Summerfelt ST (2000b) Economic analysis of an aquaponic system for the integrated production of rainbow trout and plants. Int J Recirculat Aquacult 1:15–34Google Scholar
- Alleman JE, Preston K (2002) Behaviour and physiology of nitrifying bacteria. Web archive of the Aquaculture Network Information Centre. http://www.aquanic.org/publicat/state/il-in/ces/ces-240_biology.htm
- Burgoon PS, Baum C (1984) Year round fish and vegetable production in a passive solar greenhouse. In: Proceedings of the 6th international congress on soiless culture, Luntern, Netherlands, 28 April–5 May, pp 151–172Google Scholar
- Dontje JH, Clanton CJ (1999) Nutrient fate in aquaculture systems for waste treatment. Trans Am Soc Agric Eng 42:1073–1085Google Scholar
- Goto E, Both AJ, Albright LD, Langhans RW, Leed AR (1996) Effect of dissolved oxygen concentration on lettuce growth in floating hydroponics. Proceedings of the international symposium in plant production in closed systems. Acta Horticult 440:205–210Google Scholar
- Graves CJ (1993) The nutrient film technique. Horticult Rev 5:1–44Google Scholar
- Ingram B (2002) Murray Cod aquaculture: now and into the future: outcomes from a project investigating the intensive commercial production of Murray Cod. In: Murray Cod aquaculture: now and into the future. Proceedings from a workshop held at the Victorian Institute of Animal Sciences, Attwood, Victoria, Australia, 5 August 2002Google Scholar
- Masser MP, Rakocy JE, Losordo TM (1999) Recirculating aquaculture tank production systems: management of recirculating systems. Southern Regional Aquaculture Centre Publication No. 452. Southern Regional Aquaculture Centre, USAGoogle Scholar
- McMurtry MR, Sanders DC, Patterson RP, Nash A (1993) Yield of tomato irrigated with recirculating aquaculture water. J Prod Agric 6:429–432Google Scholar
- McMurtry MR, Sanders DC, Cure JD, Hodson RG, Haning BC, St. Amand PC (1997) Efficiency of water use of an integrated fish/vegetable co-culture system. J World Aquacult Soc 28:420–428Google Scholar
- Morgan L (1999) Hydroponic lettuce production. Casper Publications, Narrabeen, NSW, AustraliaGoogle Scholar
- Rakocy JE, Hargreaves JA (1993) Integration of vegetable hydroponics with fish culture: a review. In: Wang JK (ed) Techniques for modern aquaculture. American Society of Agricultural Engineers, St. Joseph Michigan USA, pp 112–136Google Scholar
- Rakocy JE, Bailey DS, Shultz KA, Cole WM (1997) Evaluation of a commercial-scale aquaponic unit for the production of Tilapia and lettuce. In: Tilapia aquaculture: proceedings from the 4th international symposium on Tilapia in Aquaculture. Northeast Regional Agricultural Engineering Service, Ithaca, New York, pp 603–613Google Scholar
- Salsac L, Chaillou S, Morot-Gaudry JF, Lesaint C (1987) Nitrate and ammonium nutrition in plants. Plant Physiol Biochem 25:805–812Google Scholar
- Singe S, Marsh LS, Vaughan DH, Libey GS (1996) A computer simulation model to optimise greenhouse size for an integrated (fish production, hydroponics) system. Trans Am Soc Agric Eng 39:2241–2248Google Scholar
- Wren SW (1984) Comparison of hydroponic crop production techniques in a recirculating fish culture system. MSc thesis, Texas A&M University, Texas, USAGoogle Scholar