Assessment of the Fertilization Capacity of the Aquaculture Sediment for Wheat Grass as Sustainable Alternative Use

Abstract

Periodic removal of sediment from aquaculture ponds is practiced to maintain their productivity and animal welfare. The recovery of sediment as a plant fertilizer could alleviate the costs of sediment removal. The objective of this study was to test the effects of a dried sediment, extracted from an aquaculture pond used for common carp cultivation, on the growth and physiology of potted wheat grass and the quality of the juice obtained from wheat grass. The results showed that sediment application did not produce significant morphological changes, although the values for plant height (16.94-19.22 cm), leaf area (19.67-139.21 mm²), and biomass (3.39-4.26 g/plant) were higher in sediment-grown plants. However, at a physiological level, the effect was negative, decreasing photosynthesis (0.82-1.66 μmol CO₂ m²s^-1), fluorescence ΦPSII (0.737-0.782), and chlorophyll content (1.40-1.83 CCI). The juice yield was reduced in the sediment treatments (46-58 g/100 g), while the quality was improved by increasing the content of phenols (2.55-3.39 µg/mL gallic acid equivalent), flavonoids (1.41-1.85 µg/mL quercetin equivalent), and antioxidant activity (47.99-62.7% inhibition of; 2,2-diphenyl-1-picrylhydrazyl). The positive results obtained in this study can be attributed to the moderate nutrient content of the sediment and a negligible concentration of heavy metals.

Keywords: Triticum aestivum; aquaculture pond sediment; chlorophyll fluorescence; heavy metals; photosynthesis; recovery; wheat grass juice quality.

Figure 1

Chlorophyll fluorescence (ΦPSII—quantum yield of PSII of light adapted leaves) of wheat grass cultivated on pond sediment. The values represent the mean ± standard error. The lowercase letters represent a statistically significant difference (Tukey Test, p < 0.05). a.u.: arbitrary units.

Figure 2

Chlorophyll a, chlorophyll b, and carotenoids in wheatgrass juice. The values represent the mean ± standard error. The lowercase letters represent statistically significant differences according to the Tukey Test, p < 0.05. ns: not significant.