How wireless technologies can help farmers save water
Especially, soil condition monitoring shows great promise for helping farmers use water more efficiently. The sensors can now be integrated wirelessly into irrigation systems to provide real-time knowledge of soil moisture levels. Studies suggest that this strategy can reduce the water demand for irrigation of any 20% at 72% without hampering day-to-day operations on the crop fields.
What is the Agricultural Internet of Things?
Even in dry places like the Middle East and North Africa, agriculture is possible with effective water management. But extreme weather events brought on by climate change are making this more difficult. Recurrent droughts in the western United States over the past 20 years, as well as other disasters such as forest fires, have caused billions of dollars in crop losses.
Water experts have measured soil moisture to inform water management and irrigation decisions for decades. Automated technologies have largely replaced hand-held soil moisture analysis tools, as it is difficult to manually take soil moisture readings in production fields located in remote locations.
Over the past decade, wireless data collection technologies have begun to provide real-time access to soil moisture data, enabling better water management decisions. These technologies could also have many advanced IoT applications in public safety, urban infrastructure monitoring, and food security.
The Agricultural Internet of Things is a network of radios, antennas and sensors that collect real-time information about crops and soils in the field. To facilitate data collection, these sensors and antennas are interconnected cordless with agricultural equipment. The Ag-IoT is a comprehensive framework capable of sensing conditions on farmland, suggesting actions in response, and sending commands to farm machinery.
Interconnecting devices such as soil moisture and temperature sensors in the field allows control irrigation systems and conserve water autonomously. The system can schedule irrigation, monitor environmental conditions and controlling agricultural machinery, such as seed drills and fertilizer spreaders. Other applications include estimate soil nutrient levels and pest identification.
The challenges of burying networks
Wireless data collection has the potential to help farmers use water much more efficiently, but putting these components in the ground creates challenges. For example, at Purdue ENT Lab, we have found that when the antennas that transmit sensor data are buried in the ground, their operating characteristics change dramatically depending on soil moisture. My new book”Signals in the groundexplains how this happens.
Farmers use heavy equipment in the fields, so antennas must be buried deep enough to prevent damage. When the ground becomes wet, the moisture affects the communication between the sensor network and the Control system. The water in the ground absorbs the signal energy, which weakens the signals sent by the system. Denser soil also blocks signal transmission.
We have developed a theoretical model and an antenna which reduces the impact of the ground on underground communications by changing the operating frequency and bandwidth of the system. With this antenna, sensors placed in the upper layers of the soil can provide real-time information on the state of the soil to irrigation systems at distances up to 650 feet (200 meters)– longer than two football fields.
Another solution I developed to improve wireless communication in the ground is to use directional antennas to focus signal energy in a desired direction. Antennas that direct power into the air can also be used for long-range wireless underground communications.
What’s next for Ag-IoT
Cybersecurity is becoming increasingly important to Ag-IoT as it matures. Networks on farms need for advanced security systems to protect the information they transfer. There is also a need for solutions that allow researchers and agricultural extension agents to merge information from multiple farms. Aggregating data in this way will produce more accurate decisions on issues such as water use, while maintaining grower privacy.
These networks must also adapt to changing local conditions, such as temperature, precipitation and wind. Seasonal changes and crop growth cycles can temporarily alter the operating conditions of Ag-IoT equipment. Using cloud computing and machine learning, scientists can help the Ag-IoT respond to changes in the environment around it.
Finally, the lack of high-speed Internet access is still a problem in many rural communities. For example, many researchers have integrated wireless underground sensors with Ag-IoT into center pivot irrigation systemsbut farmers without high-speed Internet access cannot install this type of technology.
Integrating satellite network connectivity with Ag-IoT can help unconnected farms where broadband connectivity is still not available. Researchers are also developing vehicle-mounted and mobile Ag-IoT platforms that use drones. Systems like these can provide continuous connectivity in the field, making digital technologies accessible to more farmers in more places.
Abdul Salam is an assistant professor of computer science and information technology at Purdue University.