LED-integrated vertical aeroponic farming system for vegetable production in Singapore

Abstract

To compensate for the lack of available land and its increasing population, Singapore needs to develop its own effective farming systems that will not be influenced by climate change. Using aeroponic systems, our previous studies showed that cooling the root-zone could help produce all types of vegetables all year-round. Recently, we have developed an integrated vertical aeroponic farming (VAF) system for both indoor and greenhouse vegetable production. The key factor that determines the success of VAF system is the provision of sufficient uniform and effective light to the plants. We utilized low-energy input engineering solutions such as light-emitting diodes (LEDs) to enhance photosynthesis and thus maximize crop productivity. Our own designed LED-integrated VAF systems have been used to test the growth of various vegetable crops including green- and red-leaved lettuce (Lactuca sativa L.), Chinese broccoli, kai lan (Brassica alboglabra), nai bai (Brassica chinensis L.) and mizuna (Brassica juncea var. japonica). Various experiments have been carried out to identify the optimal combinations of LED lighting for maximal vegetable production and their impacts on photosynthesis. Our results showed that there was no close relationship between productivity and photosynthesis under different spectra of LED lighting. However, the optimal combinations of LED spectrum could enhance plant growth and photosynthesis and they are species-dependent. In conclusion, extensive development of LED-integrated VAF systems would diminish Singapore's reliance on vegetable imports, thus enhancing national food security and sustainability.