Laboratory of Environmental Control Engineering
Graduate School of Horticulture, Chiba University
By controlling the growth environment, we create suitable growth conditions for plants in plastic houses, glasshouses, and plant factories. Through our techniques, we efficiently produce high-quality food crops, ornamental plants, and medicinal plants. We analyze the responses of plants to controlled environments, evaluate their growth by using the environmental engineering approach and the ecophysiological approach, and then apply the obtained scientific knowledge to plant production.
Purpose of Plant Production
Although plants are primarily used as a food source, they are also used as sources of pharmaceuticals and energy; further, they are applied in the preservation of the environment and in industrial materials, and they have several other uses. The plant species used and the methods employed to cultivate them vary widely depending on the ultimate use of the plants.
The environmental factors that affect plant growth can be categorized into 3 groups (physical factors, chemical factors, and biological factors). The research conducted at our laboratory is mainly focused on physical environmental factors, which include aerial factors (light, air temperature, humidity, gas composition, wind, etc.) and root zone factors (solution temperature, soil temperature, dissolved gas composition, nutrient composition, etc.).
The plants subjected to research in our laboratory vary depending on the purpose of the research. We study vegetables (leafy vegetables, fruits, and herbs), medicinal plants, cereals such as rice, pulses such as soybean, ornamental plants such as orchids, and tubers such as sweet potato. We study the plants throughout their life cycles, including the stages of plant life (germination, vegetative stage, flowering, reproductive stage, and yield), in various cultivation sites.
The cultivation sites include culture vessels for tissue culture, closed nursery production systems for seedlings, greenhouses (tunnel type, plastic houses, and glasshouses), and plant factories, with natural or artificial lighting. Recently, we conducted intensive research on development of algorithms for the control of the aerial environment in large-scale commercial greenhouses and closed plant production systems. Further, we produced high-quality vegetables as functional foods by controlling the light environment, and we cultivated medicinal plants under controlled environments; we also produced genetically modified (GM) plants that contain valuable proteins, edible medicines, or other useful compounds.
1. Transplant production in closed systems
The model crops that we use for studies on transplant production include not only vegetatively propagated transplants but also seed-propagated transplants. We developed the novel concept of a closed system for transplant production in order to minimize the influences of the natural environment and to produce high-quality transplants with minimum resource usage. We are currently developing new strategies for environmental control and production management in order to optimize the performance of these transplant production systems. We expect many spin-offs from these novel research projects, which will be beneficial, not only for the growth of the agriculture industry, but also for solving global problems such as environmental conservation and the shortage of food, resources, and energy.
2. High-quality plant production in plant factories
We expanded the scope of our studies by analyzing plant production in a factory-like facility (plant factory) that functioned as a scaled-up version of our closed transplant production system. We have successfully produced high-quality vegetables and medicinal plants under controlled environments with only artificial lighting. We are currently planning to cultivate genetically modified (GM) plants in such plant factories.