The challenge of irrigation management

Farmers and nursery growers have to carefully manage water supply for their crops. Too much or too little irrigation can damage or stress the crop, making it more vulnerable to weed competition, insect pests, and/or disease. Good irrigation management is also vital in conserving water and preventing fertilizer runoff and leaching. It can be difficult to tell how much water is available underground for the crop’s roots. The amount of water in the soil and the length of time it is held there varies, depending on recent rainfall, temperature, humidity, soil type, and other factors. Additionally, plants may access different soil volumes and depths, depending on the extent of their root system. And a crop’s water requirements will vary, depending on its growth stage. So there is no “set it and forget it” easy solution for managing irrigation.

How do sensors help?

Shows the above-ground components of a soil moisture sensor installed in a potato field. — Soil moisture sensor above-ground components, including rain sensor, data logger, and solar power source. The sensor probe is hardwired to the unit. Photo credit: Marina Burani-Arouca, UF/IFAS

Soil moisture sensors are a helpful tool for farmers, providing information on crop water availability below-ground. Our sensors transmit data using cell phone antennas to provide near real-time information on the internet. Farmers can then monitor trends and adjust irrigation in response to current conditions. Moisture sensor probes collect data at different soil depths too. This allows farmers to see the soil layers in which plants take up water and the relative amounts of moisture available across the vertical soil profile.

What resources are available to support growers in using soil moisture sensors?

UF/IFAS Extension Sensor Loaner Program

Through grants from the Florida Department of Agriculture and Consumer Services (FDACS), many UF/IFAS Extension Agents across the state and here on the Treasure Coast are able to provide soil moisture sensors for growers to try out. In-ground production units come with 2- or 3-foot-long probes for deployment in crop fields. A limited number of units are also available for container-based production. The container-based units have probes measuring approximately 2 inches, for use in hydroponic or nursery production.

After installing the sensors on participating farms, Extension Agents help the growers become familiar with the data and learn how to apply the information in adjusting their irrigation schedule. So far, 11 farmers and nursery growers in Martin and St. Lucie counties have participated in the loaner program.

For more information or to participate in the loaner program in Martin County, please contact Yvette Goodiel. Elsewhere in Florida, reach out to your local UF/IFAS or FAMU Extension office or Dr. Vivek Sharma, Assistant Professor, Precision Water Management and leader of the UF/IFAS Extension statewide soil moisture sensor network.

Sensor Cost-share Programs

Federal and state agencies offer cost-share programs to support growers in protecting environmental resources. Soil moisture sensor adoption is considered an environmentally-beneficial best management practice. Growers can use the sensor data to optimize irrigation, conserving water and managing crop nutrition. Florida growers can access cost-share programs available through FDACS, USDA’s Natural Resources Conservation Service, and regional Water Management Districts. Athelly et al. (2025) provides information on Florida’s cost-share programs, including agency contacts, eligibility criteria, and funding amounts.

IrrigMonitor

Dr. Sandra Guzmán and her team at the UF/IFAS Indian River Research and Education Center are developing a user-friendly sensor data platform for growers. The platform, IrrigMonitor, helps growers translate sensor data into irrigation decision-making. IrrigMonitor shows real-time soil-moisture levels as blue/purple (soil is too wet), green (good moisture levels), and yellow (low moisture – consider irrigating, unless rains are expected).

If the sensor is equipped with an electrical conductivity (EC) meter, IrrigMonitor can also help growers use that data in managing crop nutrients. For example, growers using fertigation (fertilizer applied through the irrigation system) can see how fertilizer nutrients are moving through the soil. After a fertigation event, a peak in EC in the crop’s root zone indicates that the fertilizer has been applied where it can be used by the crop. However, if after fertigation the EC shows a peak at a soil depth well below the root zone, it may mean that crop nutrients are leaching away. Leaching of crop nutrients means that the fertilizer product is being washed away, due to excess irrigation or rainfall. Growers strive to keep the fertilizer they purchase within the root zone, to supply their crop with nutrition. Leached nutrients can contaminate groundwater, and they represent a loss for the grower.

Growers can use IrrigMonitor for:

irrigation recommendations specific to their operation;
centralized visualization of data from multiple sensors; and
technical assistance in using sensor data to optimize irrigation.

Growers interested in learning more about IrrigMonitor, contact your local UF/IFAS or FAMU Extension Agent or Dr. Sandra Guzmán.