System helps lights adapt to plants' needs in controlled environment agriculture
Controlled environment agriculture is rapidly becoming an important part of the global food system. For example, there has been much interest in the potential of large-scale, indoor agricultural production - often referred to as vertical farming - as a means to produce high quantities of produce.
A sweetpotato crop is shown in the biofeedback system. Chlorophyll fluorescence measurements are taken on the plant on the right side to determine how efficiently the plant uses the light provided by LEDs. LED light levels are automatically adjusted to maintain specific levels of physiological activity.
Photo courtesy Michael T. Martin
These "plant factories" are expensive to operate, however, in part because of the large power requirements of electric lamps that provide the type and amount of light necessary for photosynthesis in plants.
To find new methods of adapting lighting to plants' requirements in controlled environments such as vertical farms, the researchers developed and tested a biofeedback system that allows for the control of light levels based on the physiological performance of the plants.
"Controlling the intensity of light based on plants' ability to use it efficiently may substantially reduce the energy cost of LED lighting, and contribute to making large-scale controlled environment agriculture more profitable," van Iersel said.
The researchers used lettuce, pothos, and sweetpotato plants in experiments with photosynthetic light provided by a 400-Watt LED. Using chlorophyll fluorescence measurements, a datalogger determined how efficiently the plants used the light they received.
This data was used to calculate the electron transport rate (ETR), which is an indicator of photosynthesis. The datalogger then altered the duty cycle (the proportion of time that the LEDs are energized during each short on/off cycle) of the LEDs to provide more or less light.
The target ETR was altered in a stepwise pattern over a 15-h period. The biofeedback system was capable of automatically adjusting the light levels to assure that the desired ETR was reached. As the target ETR was increased, light levels increased as well. In addition, conversion of light energy into heat (a common way for plants to deal with excess light) was upregulated, while the light use efficiency decreased.
As the target ETR was decreased during the last 7 hours, conversion of light into heat decreased greatly in lettuce and pothos, with only a small increase in light use efficiency. "This suggests that the light use efficiency of lettuce and pothos was limited by a process other than conversion into heat, likely light-induced damage to the photosynthetic machinery in the leaves," the authors noted.
"The biofeedback system successfully maintained a wide range of ETR values in different species, while it also is capable of distinguishing between conversion of light into heat and damage to the photosynthetic machinery as causes for decreases in light use efficiency," the authors said. They said the biofeedback system has potential applications in controlled environment agriculture, as well as basic plant physiology studies, where the system can be used to maintain specific levels of physiological activity.
The complete study and abstract are available on the ASHS J. Amer. Soc. Hort. Sci. electronic journal web site: http://journal.
Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at ashs.org
Michael W. Neff | EurekAlert!
Cascading use is also beneficial for wood
11.12.2017 | Technische Universität München
The future of crop engineering
08.12.2017 | Max-Planck-Institut für Biochemie
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
12.12.2017 | Physics and Astronomy
12.12.2017 | Earth Sciences
12.12.2017 | Power and Electrical Engineering