Efficient water management is a growing concern for farmers living in arid or semi-arid environments. Using sensors to detect soil conditions removes sources of human error when it comes to the efficient and productive use of water resources. Bluetooth is a low cost method of communication between in-field sensors and base processors which use software to control sprinklers and drip irrigators.
BLE: 4x the Range, 2x the Speed, 8x the Data
Bluetooth has become increasingly efficient and affordable since the turn out of Bluetooth Low Energy (BLE). Bluetooth Low Energy is twice as fast and capable of carrying eight times more data four times further than previous Bluetooth protocols. Bluetooth’s ubiquity makes it perfect for heterogenous, ad-hoc networks – it is inherently scalable and small-time rural farmers as well as corporate agri-giants can utilize the technology.
Farmers and IoT
As world population rises and arable land declines, efficiency is key. Easing the labour burden for farmers using IoT and raising profitability by increasing yields are the two main benefits of using IoT to inform decision making processes and automate as many tasks as possible. While this article focuses on irrigation, farmers are using connected sensor systems to perform a host of operations.
Sensors are small devices which capture data on environmental conditions. Sensors help farmers make informed decisions by enabling real-time traceability and diagnosis of crop, livestock, and mechanical states. By detecting nascent issues, farmers can nip problems in the bud – preventing huge losses due to irregular watering, parasites, or machine failure.
Sensors can detect soil pH and mineral presence. Infrared sensors can bounce light off of plants and detect stress due to parasites or disease. In greenhouses, farmers use lux sensors to detect whether optimal light levels have been reached. Overall, farmers are using IoT for the early detection and prevention of negative outcomes as well as to reduce human error and labour costs through automation.
On a Farm, Wireless is Best
Imagine what a nightmare it would be to use wires to facilitate sensor-base communication on a farm. Wireless Sensor Networks (WSNs) are the way to go. Zhang et al. evaluated the effectiveness of Bluetooth facilitated WSNs ten years ago. His study found that the optimal height for the radio transmitting devices was 1.4 meters. Bluetooth 5.0 has quadrupled the range used in his study from 44m to 176m. Powerful Bluetooth Low Energy Gateways or Relays can be positioned on small platforms throughout a field. These Gateways can relay data from in-soil sensors to a Base Station, where the data is processed, fed into a software program, and the information derived used to trigger corrective or remedial actions.
Distributed, In-Field WSN
A team of researchers in 2010 applied an in-field WSN using five in-field sensing stations, an irrigation control station, and a base station. The in-field sensing stations were outfitted to monitor soil moisture, soil temperature, air temperature, relative humidity, precipitation, wind speed, wind direction, and solar radiation. The readings from the various sensors were wirelessly transmitted to the base stations via Bluetooth radio. The data was fed through software which sent control commands to the irrigation control stations. The GPS location of sprinklers allowed the software program to georeference which stations to turn on and for how long to achieve a specified water depth.
From the Field to the Smartphone
Over the past 10 years, the technology available to data scientists and farmers have become highly sophisticated and user-friendly. Most sensors on the market today can communicate directly with a user’s cellphone via application, eliminating the need for middle-man data loggers. Bluetooth mesh networks and piconets form secure, self-optimizing, and self-healing networks. For an overview of the different connections that can be formed between sensor nodes and gateways, check out this guide
To see examples of state of the art sensors, we recommend taking a quick look at the HydraProbe, and EcoTech Tensiomark from Steven’s Water.
We also recommend checking out Davis Weather Monitoring products. Their nodes and gateways are ad-hoc and compatible with third party sensors.
Farming is a low-margin enterprise. Saving money and labour on an incremental scale add up to substantial gains.
“Water is precious and too much or too little will make or break my crop. I save money on water and pumping costs, while making sure that the water applied reaches the tree roots.” – Jay Watson, Apple Farmer, California
The world’s population will exceed 9.1 billion by 2050. Farmers will need to harness all the government and technological supports available to ensure supply keeps up with demand. As an affordable, ubiquitous technology, Bluetooth is opening doors for small and large scale farmers everywhere to take advantage of actionable data.