The internet of greenhouse things

The transfer of data between objects — known as the Internet of Things (IoT) — is big business, from cell phones to smart speakers to toys to refrigerators. Now, there are opportunities for its use among cameras, sensors and other equipment in greenhouses that relay data to physical or cloud servers. As early greenhouse models show, it can be a means of sharing information with others or remotely controlling greenhouse processes.

One sensor, multiple operations

One greenhouse IoT application involves using internet-connected devices so that multiple growers can communicate among themselves and with researchers to share information. For example, Krishna Nemali, assistant professor of controlled environment agriculture at Purdue University, is developing “next-gen sensors” to measure seedling quality and plant nitrogen content.

Nemali plans to issue growers a $150 nitrogen sensor with a few different components that can be used with a smartphone. The growers will take images to receive nitrogen readings.

This system utilizes IoT because information pulled from devices at the numerous greenhouses is sent to a server, processed and sent back to the growers. To participate, growers need reliable internet connectivity.

Nemali explains potential faults in data collection that doesn’t utilize IoT. “Let's say you select 50 growers all over the country and you give them the same instrument and ask them to measure and send you the data, there will be errors in the way they measure and there could be calibration issues with these sensors with time,” he says. “Then they all collect the data, but the data may not come to one central location on time.”

But with IoT as it is used in Nemali’s application, images are sent to a server that analyzes them using one programming code. Large amounts of data — sometimes referred to as “big data” — is collected by Purdue. With the project still in its early stages, the university will try to improve the system while sharing all of the participating growers’ data among their group.

“My goal is to … take it way beyond research so more growers use it and to make sure the technology is adapted quickly and the beneficial technology is seen by many growers,” Nemali says.

Multiple sensors, one operation

In another application of IoT technology, numerous sensors and cameras connected to each other via the internet could allow a single operation to monitor and remotely adjust various conditions such as temperature, humidity, supplemental lighting, irrigation and shade curtains.

Whereas Nemali’s technology allows information to be shared between a university and multiple growers, Ahmed Khattab of Cairo University has researched a layered greenhouse IoT system with multiple components that can be outfitted through a single operation.

Khattab, an associate professor in Cairo University’s Department of Electronics and Electrical Communication Engineering, co-authored the SN Applied Sciences paper, “A layered IoT architecture for greenhouse monitoring and remote control.” It presents a system design with multiple cameras, sensor nodes and actuators, as well as an access point, microcontroller and cloud connectivity. It has both an Ethernet and WiFi connection — Ethernet because it helps heavy data traffic from the cameras.

“Here, we have different nodes because we have to be more reliable — if something went out, we would not want the entire system to go out,” Khattab says. “Also, we split the functionality across different layers. We have one layer just for data collection and action implementation, one separate layer just for communication, another layer for decision-making and processing the data.”

The system can be used throughout multiple greenhouse structures at one site, or even greenhouses at different sites that are part of the same business entity.

“[Data] are collected in a centralized place, and he or she can see everything, like he can control multiple greenhouses in different locations simultaneously.” — AHMED KHATTAB

“The grower can have separate greenhouses … across the country,” Khattab says. “[Data] are collected in a centralized place, and he or she can see everything, like he can control multiple greenhouses in different locations simultaneously.”

In the application in Khattab’s paper, price can vary greatly depending on the size of the greenhouse that is being outfitted and the number of devices and cameras. Between cameras, an Ethernet switch, installation and IoT application software, a grower may need to shell out $1,000 or more, he says.

Nemali says he has worked with a lettuce grower in Atlanta that uses numerous WiFi sensors that communicate data about water, light and temperature with a central unit.

He adds that growers who are collecting data in a similar way can still share it. “They can also send that data to a central location, like what I described for the nitrogen sensor, and further process all of the data and make useful — summarize that and make some useful recommendations for growers all over the region,” he says. “So, it can be done in many ways.”

For more information on Nemali’s sensing technology, visit bit.ly/gm-nemali and bit.ly/cultivate19-nemali.