Exploring Microelement Fertilization and Visible-Near-Infrared Spectroscopy for Enhanced Productivity in Capsicum annuum and Cyprinus carpio Aquaponic Systems

• Published in: Plants (Basel) 2024-12, Vol.13 (24), p.3566
• Main Authors: Sirakov, Ivaylo, Stoyanova, Stefka, Velichkova, Katya, Slavcheva-Sirakova, Desislava, Valkova, Elitsa, Yorgov, Dimitar, Veleva, Petya, Atanassova, Stefka
• Format: Article
• Language: English
• Subjects: Agricultural production; Ammonia; aquaponic system; Aquaponics; Biomass; Capsicum annuum; Carp; Chlorophyll; common carp (Cyprinus carpio); Crop diseases; Crop production; Cyprinus carpio; Dissolved oxygen; Electric properties; Exposure; Fertilization; Fishes; Fruits; influence; Infrared spectra; Infrared spectroscopy; Investigations; Metabolism; microelements; Near infrared radiation; Nondestructive testing; Nutrient content; Nutrient dynamics; Nutrient status; Nutrient uptake; Nutrients; Optimization; Orthophosphate; Parameters; pepper (Capsicum annuum); Peppers; Plant growth; Plant layout; Plant pigments; Plants (botany); Productivity; Root development; Spectral analysis; Spectrum analysis; Systems stability; Trace elements; Water chemistry; Water management; Water quality; Wavelengths
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants13243566

This study explores the effects of varying exposure times of microelement fertilization on hydrochemical parameters, plant growth, and nutrient content in an aquaponic system cultivating L. (pepper) with ( L.). It also investigates the potential of visible-near-infrared (VIS-NIR) spectroscopy to differentiate between treated plants based on their spectral characteristics. The findings aim to enhance the understanding of microelement dynamics in aquaponics and optimize the use of VIS-NIR spectroscopy for nutrient and stress detection in crops. The effects of microelement exposure on the growth and health of ( L.) in an aquaponic system are investigated, demonstrating a 100% survival rate and optimal growth performance. The findings suggest that microelement treatments, when applied within safe limits, can enhance system productivity without compromising fish health. Concerning hydrochemical parameters, conductivity remained stable, with values ranging from 271.66 to 297.66 μS/cm, while pH and dissolved oxygen levels were within optimal ranges for aquaponic systems. Ammonia nitrogen levels decreased significantly in treated variants, suggesting improved water quality, while nitrate and orthophosphate reductions indicated an enhanced plant nutrient uptake. The findings underscore the importance of managing water chemistry to maintain a balanced and productive aquaponic system. The increase in root length observed in treatments 2 and 6 suggests that certain microelement exposure times may enhance root development, with treatment 6 showing the longest roots (58.33 cm). Despite this, treatment 2 had a lower biomass (61.2 g), indicating that root growth did not necessarily translate into increased plant weight, possibly due to energy being directed towards root development over fruit production. In contrast, treatment 6 showed both the greatest root length and the highest weight (133.4 g), suggesting a positive correlation between root development and fruit biomass. Yield data revealed that treatment 4 produced the highest yield (0.144 g), suggesting an optimal exposure time before nutrient imbalances negatively impact growth. These results highlight the complexity of microelement exposure in aquaponic systems, emphasizing the importance of fine-tuning exposure times to balance root growth, biomass, and yield for optimal plant development. The spectral characteristics of the visible-near-infrared region of pepper plants treated with microelements revealed subtle