Articles
Cultivation of blitum (Amaranthus blitum) in hydroponic and aeroponic systems intended for cultivation under netting on building rooftops for urban food production using grey water for irrigation
Article number
1437_8
Pages
57 – 62
Language
English
Abstract
Urban food production on building rooftops using lightweight cultivation systems has gained attention due to its economic, environmental, and social benefits.
This study compared three cultivation systems – a conventional green roof (S, 12 cm substrate, control), a hydroponic system (H, perlite bags), and an aeroponic system (A) – under two fertigation schemes: Hoagland nutrient solution with tap water (F) or graywater (G). Sixteen weighing lysimeters (2×1 m) were used, each with 18 Amaranthus blitum plants, while two lysimeters remained unplanted.
Plant growth and health were assessed using growth index (GI), SPAD, stomatal conductance (SC), and relative chlorophyll fluorescence (Fv/Fm). Results showed that ST had the highest GI (21.0 cm), followed by H (17.8-18.8 cm), while A had the lowest (14.7-15.1 cm). SPAD values were lowest in S (48.6), intermediate in A (53.8-58.1), and highest in H (57.4). SC increased with graywater in H (402.5 mmol m‑2 s‑1) and A (390.0 mmol m‑2 s‑1), while the lowest SC was in AT (219.0 mmol m‑2 s‑1). Fv/Fm differences were not significant.
Structurally, A was the lightest (0.081423 kNm‑2), H intermediate (0,430659 kNm‑2) and S the heaviest (1.308654 kNm‑2). These results provide insights into optimizing urban rooftop cultivation based on structural and agronomic considerations.
This study compared three cultivation systems – a conventional green roof (S, 12 cm substrate, control), a hydroponic system (H, perlite bags), and an aeroponic system (A) – under two fertigation schemes: Hoagland nutrient solution with tap water (F) or graywater (G). Sixteen weighing lysimeters (2×1 m) were used, each with 18 Amaranthus blitum plants, while two lysimeters remained unplanted.
Plant growth and health were assessed using growth index (GI), SPAD, stomatal conductance (SC), and relative chlorophyll fluorescence (Fv/Fm). Results showed that ST had the highest GI (21.0 cm), followed by H (17.8-18.8 cm), while A had the lowest (14.7-15.1 cm). SPAD values were lowest in S (48.6), intermediate in A (53.8-58.1), and highest in H (57.4). SC increased with graywater in H (402.5 mmol m‑2 s‑1) and A (390.0 mmol m‑2 s‑1), while the lowest SC was in AT (219.0 mmol m‑2 s‑1). Fv/Fm differences were not significant.
Structurally, A was the lightest (0.081423 kNm‑2), H intermediate (0,430659 kNm‑2) and S the heaviest (1.308654 kNm‑2). These results provide insights into optimizing urban rooftop cultivation based on structural and agronomic considerations.
Publication
Authors
P.A. Nektarios, K. Gaitanaki, I. Mpaira, D. Harkoutsis, K. Ferro, I.N. Daliakopoulos, D. Paradimitriou, T. Manios
Keywords
green roofs, weighing lysimeters, urban agriculture, recycled irrigation water
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