Aquaponics Production of Wheatgrass (Triticum aestivum L.) in Different Horticultural Substrates with African Catfish (Clarias gariepinus) in Northern Germany

Xu, Lu; Ziethen, Christopher J.; Appelbaum, Samuel; Palm, Harry W.; Knaus, Ulrich

doi:10.3390/agriengineering4040067

Cited by 3 publications

(1 citation statement)

References 63 publications

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“…The issue, however, with using the term ‘ on demand ’ is that it is possible to have water flowing ‘ on demand ’ in both coupled and decoupled installations. Coupled aquaponics can be built as a continuous throughflow of the RAS water as process water for the plants (permanently) or discontinuously (‘ quasi‐closed loop ’ or ‘ semi‐coupled ’ according to Schmautz et al 65 , Nozzy et al 66 , Knaus et al 45 ), where the water is pumped on‐demand to the plants, utilised in for example, ebb and flood table systems for some time for plant usage and water cleaning (multiple pass), and then pumped back (discontinuous) to the aquaculture unit 45,67 . This technically requires a water transfer point as a reservoir (e.g.…”

Section: The Issue Of Couplingmentioning

confidence: 99%

Aquaponics nomenclature matters: It is about principles and technologies and not as much about coupling

Palm,

Knaus,

Kotzen

2023

Reviews in Aquaculture

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The food production system ‘aquaponics’ has moved a long way from its inceptions in the 1970s and 1980s. This paper suggests that it is the principle of aquaponics that should define what aquaponics is and then the rest follows according to systems and technologies. This paper supports the Palm et al. (Aquac Int. 2018;26(3):813–42) position of having a nutrient supply threshold (>50%) from the feed via the aquatic organisms to the plants. We test the most recent alternative definitions (e.g. Baganz et al. Rev Aquac. 2021;14:252–64) that overcomplicate existing definitions and nomenclature. Any new definition needs to be referential to existing terms and properly tested. This paper does exactly that, concluding that several recent changes by Baganz et al. (Rev Aquac. 2021;14:252–64) are not needed. We also debate that the key principle behind aquaponics is ‘all about coupling’. Whilst coupling is an important aspect, existing technologies and those that will emerge are far more complex. Finally, this paper highlights the idiosyncrasies in the term aquaponics and we suggest an alternative term ‘aquaorganoponics’, which in essence better describes the principles of aquaponics (s.s.) which transfers natural organic compounds combined with microbes in water from the aquaculture unit to the plants.

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Section: The Issue Of Couplingmentioning

confidence: 99%

Aquaponics nomenclature matters: It is about principles and technologies and not as much about coupling

Palm,

Knaus,

Kotzen

2023

Reviews in Aquaculture

Self Cite

View full text Add to dashboard Cite

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Suitability of coconut bran and biochar as a composite substrate for lettuce cultivation in aquaponic systems

Zhu,

Lin,

Fen

et al. 2024

Heliyon

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Effects of Zn-EDTA on the health and welfare of the African catfish, Clarias gariepinus (Burchell, 1822), in a recirculating aquaculture system

Hildebrand,

Rebl,

Goldammer

et al. 2024

Front. Aquac.

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As nutrient-rich water in aquaponic systems cannot supply growing plants with all the required trace elements, supplementation with specific fertilizers is performed to make up for this deficit. While chelated fertilizers such as ethylenediaminetetraacetic acid–zinc disodium complex (Zn-EDTA) are becoming more popular in this context for improving plant growth in aquaponic systems, little is known about their effects on fish. During two experiments, a total of 576 individuals of catfish fry (0.19 g) and fingerlings (220.01 g) of the African catfish (Clarias gariepinus; Burchell, 1822) were kept separately for 32 days under experimental aquarium conditions. The fry was exposed to 0.125 and 0.5 mg/L, while the fingerlings were exposed to 0.5 and 2.0 mg/L Zn-EDTA in a plantless aquaponic system. The third treatment group consisted of a control group without Zn-EDTA. The growth, mortality, and ethological indicators were assessed for all growth stages, while the leukocyte distribution and histopathological changes were additionally determined for the fingerlings. As the feed intake in the experiment was limited, the investigations were focused on the effects of Zn-EDTA and not on the growth process of a respective fish growth stage. While the growth, mortality, and behavior were not significantly different in both growing stages, the number of mature neutrophils changed significantly in all treatments in fingerlings. Zn was not detected in the histologically investigated organs at the tested concentrations using the staining method. However, morphological alterations of the gill epithelium were found on the secondary lamellae. Quantitative multiplex PCR was used to simultaneously evaluate the expression of 17 genes related to Zn metabolism and stress physiology in head kidney samples. The transcripts of several selected genes changed by up to 70-fold. Due to high individual variances, only the copy numbers of the KMT2A (lysine-specific methyltransferase 2a) gene were significantly different across treatment groups and sampling points. However, the present results indicate that the addition of Zn-EDTA at the tested concentrations can be considered relatively benign for the health and welfare of C. gariepinus, as no toxic effects of Zn-EDTA were observed in moderately hard to hard water.

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Aquaponics Production of Wheatgrass (Triticum aestivum L.) in Different Horticultural Substrates with African Catfish (Clarias gariepinus) in Northern Germany

Cited by 3 publications

References 63 publications

Aquaponics nomenclature matters: It is about principles and technologies and not as much about coupling

Aquaponics nomenclature matters: It is about principles and technologies and not as much about coupling

Suitability of coconut bran and biochar as a composite substrate for lettuce cultivation in aquaponic systems

Effects of Zn-EDTA on the health and welfare of the African catfish, Clarias gariepinus (Burchell, 1822), in a recirculating aquaculture system

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