Improving light use efficiency in vertical farms with dynamic lighting strategies.

Vertical farming is a completely controlled-environment production system that can continuously produce at high quality and quantity, and high water, nutrient, and land-use efficiency. However, its energy consumption (about 75% for lighting) is much higher than that of conventional agriculture. Thus, it is vital to improve light use efficiency (biomass production per unit of light input) in vertical farming for its future. This research aims to identify and quantify possibilities to improve light use efficiency by applying dynamic lighting strategies Daily light/dark cycles, as well as light quality, entrain the oscillator of plant circadian clock. The clock influences plant growth and development and this may provide options to enhance yield. Dynamic lighting strategies here include several light/dark cycles within 24 h, different photoperiod, and/or different light quality during the crop cycle. The project will start with investigating the effect of the number of light/dark cycles within 24 h on growth, carbohydrate accumulation, and expression of related circadian clock genes. Furthermore, effects of alternating sole red and blue light and simultaneous red and blue light will be compared and analyzed mainly on photosynthetic functioning. An elaborate literature study will focus on the interaction between continuous light and light spectrum on enhancing biomass and injury-free producing, followed by some dedicated experiments to explore the possibilities. All experiments will be conducted with tomato seedlings. Results from this study are expected to stimulate dynamic lighting strategies and promote light use efficiency in vertical farming.