Student: Therin Young, Graduate Student in Mechanical Engr, University of Iowa
Faculty Mentor: Dr. Baskar Ganapathysubramanian
High-Throughput Plant Phenotyping in Controlled Environments for Space Agriculture Applications
As manned space flights into deep space become more of a reality, the need to grow crops for food and medicinal purposes onboard spacecraft becomes essential to the nourishment and mental stability of space travelers. However, there are challenges associated with growing plants in space. Challenges include zero gravity, radiation exposure, reduced lighting, nutrient delivery, and limited available space. For these reasons, space-grown plants are grown in closed, controlled environments or plant growth chambers to ensure that plants receive the necessary components to carryout photosynthesis and produce. In addition, plant scientists aboard the space craft phenotype or measure the physical traits of the plants during and after the growing process. Phenotypic traits might include flower color, plant height, or leaf angle, and these traits can provide information about the health of the plant based on the chamber environmental parameters as well as assist scientists in predicting plant behavior and optimizing plant yield. Traditional phenotyping methods would require the scientist to make measurements inside the chamber visually and/or manually, thus potentially exposing the plants to a harmful environment. Therefore, there is a need for a high-throughput phenotyping platform that circumvents the current challenges of phenotyping in controlled environments.
Computer vision is an attractive area of study in precision agriculture that allows scientists to capture 2-D images of plants and extract physical traits from the images that can be measured and used to assist farmers with making better crop predictions for increased yields. For my research, I will use computer vision techniques to phenotype plants growing in a closed environment which simulates that of a plant growth chamber in space. Habitats for Organisms and Modular Ecosystems (HOME) is a new technology in development at Iowa State University that utilizes transparent interlocking plastic bricks to build air-tight scalable housings for growing plants in user-controlled environments. The transparency of the HOME building materials makes it a good candidate for computer vision applications. Additionally, a HOME uses transparent soil as the medium for nutrient delivery thus allowing for non-invasive imaging and phenotyping of plant root systems. The scalability of HOMEs and their ability to utilize hydroponics and aeroponics as plant nutrient delivery systems also makes them a good candidate for vertical farming applications which would be useful for spacecrafts with limited space for growing plants. Vertical farming, which is the practice of growing plants vertically on stacked shelves indoors under a controlled environment, is a farming method that can allow for increased crop production without adding additional stress to the soil. Another research approach is 3-D reconstruction from multiple 2-D images to create 3-D replicas of plants that give information about the plants’ depth (ex. stem and root thickness in zero-gravity environment).