Frost Protection and Soil Moisture Control in Cranberry Bogs
Challenge
Cranberry bogs need to be monitored for proper soil moisture and air temperature at the vine level.
Maintaining the proper soil moisture is critically important for healthy cranberry plants. The root system of a cranberry plant is relatively shallow, requiring a specific soil moisture content to grow and produce fruit.
Air temperature is monitored to protect crops from frost. When the temperature nears freezing, the irrigation system is automatically turned on to protect the plants. Water and energy are conserved because the irrigation system is only used when the temperature is near freezing.
Solution
Soil moisture and air temperature sensing ranges are typically under a mile, but the Site Survey tested the signal out to two miles. With the MultiHop Radio and its antenna installed very low to the ground, a Master Radio was installed with a large omnidirectional antenna to maximize the communication range.
A MultiHop Slave Radio with analog inputs and an SDI-12 interface for a soil moisture probe is mounted on a stake driven into the ground in the cranberry bogs. A thermistor connected to an input on the Slave Radio monitors soil and ambient temperatures.
Soil moisture content and temperature data is wirelessly transmitted back to a DXM100 Wireless Controller. When air temperatures drop below specific limits, the DXM100 sends text messages to the farmers. This frost early warning system allows the farmers to take appropriate actions to minimize possible crop damage. Soil moisture levels are logged with the DXM100, allowing the farmers to more efficiently irrigate their fields and conserve water while also reducing energy costs.
Based on this installation, the integrator estimated 1.5 year battery life, allowing the customer to include battery replacement on an annual schedule.
The Sure Cross® wireless network operates outside the Wi-Fi network and provides local control of data even if the Wi-Fi connection is lost. In this installation, independence from an Internet connection was an important consideration. Many rural farming areas do not have access to a reliable high-speed Internet connection so wireless data collection solutions cannot rely the Internet for a frost early warning alarm system.