Aquaponics model specific to South African conditions
Aquaponics is the integration of aquaculture (fish) and hydroponic culture (plants) as one system. Aquaponics requires a sound simultaneous understanding of two agricultural ecosystems (fish and plants) in order to have a viable system. Modelling and model development is sacrosanct in systems where productivity is uncertain or complex. The study was conducted in 2016 to collect aquaponics information in the Republic of South Africa (RSA) using an online survey questionnaire to determine local aquaponics uses, management and distribution. A total of 44 aquaponics operators were captured within three months (September-November) in 2016. In this study, it was shown and concluded that most aquaponics practitioners in RSA do not have adequate knowledge and skills in aquaponics production and management, and that development of the localised aquaponics model is important for South Africa. As a result, the aim of this study was to develop a model that is more specific to South African conditions in order to help South Africans to have a better opportunity to establish and operate aquaponic systems. This study was designed as a mixed approach combining different methods and sources of data to develop the model. Unified Modelling Language (UML), Microsoft excel, an online survey, observations, structured and unstructured interviews and content data were used. The developed model was able to predict the main aquaponics inputs variables, namely fish stocking density, daily fish feed, and required planting area. The fit for each of these variables was good to average with R=0.7477, 0.6957, and 0.4313 respectively. There were no significant differences (P<0.05) between the observed and simulated data for all variables (fish stocking density, daily fish and planting area variables). Therefore, it was concluded that this model can be adopted by aquaponics practitioners in RSA and extension officers or facilitators as an aquaponics start-up platform.
Keywords: Fish stocking density, daily fish feed, plant growing area, aquaponics model