Evaluation of the Resource Use Efficiencies of Small-Scale Vertical Hydroponic Structures against Growing Plants in Soil

Abstract

The aim of this research was to investigate the use of small-scale vertical farming structures as an alternative to improving resource use efficiency in agriculture. To achieve this, Fordhook Giant Swiss chard was grown over two cropping seasons between February and November 2019 at the Ukulinga Research Farm in Mkondeni, Pietermaritzburg. The main factor was the growing method. The sub-factors were light provision and nutrient solution concentration. The hydroponic structures had a significantly higher land use efficiency than the plant pot setup (3 041.05 g.m-2 vs 405.89 g.m-2 in cropping season one (CS1), and 3 106.41 g.m-2 vs 464.53 g.m-2 in CS2), p < 0.0005. The crop water productivity of the hydroponic structures was significantly higher than that of the plant pot setup (8.45 g.L-1 vs 5.72 g. L -1 in CS L and 8.44 g.L-1 vs 6.59 g.L-1 in CS2), p < 0.0005 in CS1 and p = 0.014 in CS2. The energy use efficiency of plants grown hydroponically under sunlight (104.25 g. KWh-1 in CS1 and 103.43 g. KWh-1 in CS2) was significantly higher than that of plants grown hydroponically under grow lights (12.30 g. KWh-1 in CS1 and 12.80 g. KWh-1 in CS2). It was also significantly higher than plants grown in soil under grow lights (8.16 g. KWh-1 in CS1 and 9.29 g. KWh-1 in CS2), p < 0.0005. The vertical hydroponic structures had higher resource use efficiencies than soil planting. The research showed that small-scale hydroponic structures can be used to improve agricultural productivity. © 2022 Friends Science Publishers