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Whether growing plants in a greenhouse or indoors, many technologies have aided in the advancement of these growing systems by providing the utmost environmental control. Today, you often hear the term “precision agriculture” or “precision indoor plants” due to the high level of precision inputs, which results in crops with the highest uniformity. Because plants are highly affected by their environment, maintaining a consistent growing environment is crucial. By integrating specific technologies into your growing systems, you can design a highly precise, consistent growing environment. Some of these technologies such as those manufactured by Microchip Technology, a leading provider of microcontrollers as well as many other devices, correspond with one another to make this possible, such as sensors, Internet of Things (IoT), microcontrollers (MCUs), and light-emitting diode (LED) lighting. Here, we will describe how each function and how they work together in controlled environments.
Sensors detect changes in their environment and relay those changes to another computer device such as an MCU. These sensors can detect various environmental factors such as light quality and quantity, temperature, relative humidity, CO2 levels, wind speed, and soil moisture content, which all are essential in precision growing. One common example is the importance of knowing your light quantity, considering that light is one of the most significant limiting factors in plant growth. Through sensors, we can quantify any of these factors so that we can make the proper adjustments to optimize plant growth. A sensor does not work alone; however, as it requires another type of electronic device to output data, such as an IoT device, a microcontroller, or another processor.
Internet of Things (IoT) is the connectivity of everyday devices to the internet. One example of IoT technology in everyday use would be a smart-home device such as “Ring” or “Nest”. IoT made its first appearance in a Coke vending machine that could report its inventory and beverage temperature in 1982, which was novel at the time. Since then, innovators have made many advances in IoT technology.
IoT plays a crucial role in precision agriculture systems where it can receive data from a sensor and relay that information to the grower via a computer or mobile device on any inputs that a sensor can gather. Through this information, growers can make more informed decisions to improve efficiency and maximize crop yields remotely and wirelessly.
MCUs are essentially small computers with similar components to a regular one, but the smaller size plays to their advantage. MCUs are usually dedicated to one single task, one on which it can focus. MCUs are all around us in everyday items such as TVs, radios, and refrigerators. In a controlled environment growing setup, an MCU or group of MCUs can serve as the brain to turn off/on various units such as LED grow lights, heaters, coolers, and humidifiers to maintain the desired set point through the integration of the sensor’s output. For example, on a cloudy day, low-light levels will limit growth, so it would trigger turning on the supplemental light, but on a sunny day natural lighting may be enough so the lights turn off to save energy. This removes the guesswork from the growers, allowing them to focus on other tasks while achieving a consistent growing environment automatically.
The application of LEDs in horticulture also accelerated precision and efficiency in growing systems. LEDs have many advantages over traditional incandescent lamps, including lower power consumption, longer lifetime, reduced heat load, and a much smaller size. The smaller size and reduced heat allow placement close to plants, maximizing density in vertical farm applications and allowing placement between foliage canopies for vine crops such as tomatoes. LEDs also have the option to be dimmable, giving you additional control and can be set up with IoT and MCUs. Through many plant studies, we know that plants have the highest quantum yield when grown under solely red and blue wavelengths, meaning plants use these colors most. Although plants do perceive and use other wavelengths, it is most efficient to maximize the energy use on wavelengths that return the highest yield, adding to the efficiency of LEDs. LEDs have also aided in many unique plant growth studies and discoveries due to their tunability to light ratios that were not possible before. One example of this is the use of light flickering and mobile LED bars to effectively satisfy plants with long day length requirements as well as reduce energy and fixture costs. Although more plant growth research is needed, we know that different species have unique light recipes to maximize yield, which LEDs can achieve through their tunability. Therefore, just like crops have specific nutrient requirements, they also have an optimal light spectrum as well.
By integrating sensors, MCUs, IoT devices, and LEDs into growing systems, we can provide the highest precision in environmental control to maximize efficiency and yields in plant growth. These technologies work together to support a consistent growing environment by sensing a plant’s environmental conditions, sending the information to connected devices, and adjusting the growing conditions (i.e., light levels and wavelengths) for optimal plant growth.
Brandon Huber is a PhD student at North Carolina State University in Horticultural Sciences. His research area is in the controlled environment horticulture lab, where he studies the benefits of supplemental CO2 as a tool to reduce production costs in enclosed growing environments. In conducting these research experiments, they use many sensors and data loggers to precisely control and record environmental factors, minimizing environmental noise in experiments. Through this research they’ve found you can reduce production time and or reduce lighting demand while maintaining quality growth. Additionally, he has expertise in plant breeding in which he did his MS.