Bioponics for lettuce production in plant factory with artificial lighting

Abstract

Plant Factory with Artificial Lighting (PFAL) gains worldwide attention and the most popular culturing system is hydroponics which pure soluble inorganics fertilizers were used. The manufacturing process of these fertilizers are not environmental friendly. A new trend termed ‘Bioponics’ using organic fertilizer brought to our attention. This study aims at using two organic fertilizers (BIO N and BIO NK, Swiss Hydroponics Lab.) in a DFT system in PFAL producing Frill-ice lettuce, Boston lettuce and Frilly lettuce. Using Yamazaki formula (inorganic fertilizer) as the control group. The environmental settings of the PFAL are as follows: PPFD kept at 200 μmol m-2s-1, day/night temperature at 25/18℃ and CO2 concentration at 1200 ppm. Results showed that the control group has the highest fresh mass in Frill-ice lettuce. Bioponics treatments greatly reduced the nitrate concentration of all lettuce and increased the fresh mass of Frilly lettuce. BIO N is not suitable for Boston lettuce. Further studies will be conducted using BIO NK and the Frill-ice lettuce. Using organic fertilizer in PFAL looks promising, however, the products of Bioponics can be considered organic products or not is still in controversy.