New modified technologies for ORBITEC plant growth systems

Abstract

Vegetable cultivation plays a crucial role in dietary supplementation and crew psychosocial benefits for long duration space flight. Biotechnology and engineering control technologies should be seamlessly integrated to build better plant growth systems for future crewed space missions. Improvement of crop yield and quality by controlling lighting systems, plant growth accommodation and nutrient delivery systems is therefore a matter of interest for researchers in both space and urban agriculture fields. Researchers at NASA Kennedy Space Center and ORBITEC have a heritage in developing space flight plant growth systems. The objectives of this study was to integrate new controlled environment agriculture technologies into an ORBITEC ground-based plant growth system(Biomass Production System for Education – BPSe) and investigate the influences of different environmental factors on the morphological, physiological characteristics and biomass yield of different crops. To address this issue, we evaluated the response of tomato (Lycopersicon esculentum Mill.) and lettuce (Lactuca sativa L.) plants by using a modified BPSe. Results showed that the plant morphological characteristics were partially influenced by interaction effects with the environment, and this influence decreased gradually with plant development. Combined utilization of UV light and ozonation decreased the amount of fungi within the nutrient solution significantly. The BPSe was enhanced with a high-pressure aeroponic irrigation system in order to prevent potential salt built-up within the root compartment and to generate an oxygen-enriched environment within the root zone. Aeroponics is a soilless irrigation method that uses a nutrient-water spray in order to inject the nutrient solution directly into the root compartment, where the plant’s roots are hanging freely. The excess solution is recovered and fed back into the loop. Aeroponics has the potential for use in both microgravity and planetary surface plant growth systems. The response of physiological and biochemical changes to different environments can provide a theoretical basis for further research to improve energy efficiency and develop high yield cultivation techniques. Our findings may be used to design specifically balanced cultivation systems for supporting plant growth, especially for specialized applications, such as in space and urban agriculture. These will play a critical role in further development of ground, space plant factory and integral experiments.