Where to place moisture sensors

Right now, extension specialists like Dr. Kevin Frank at Michigan State University recommend irrigation sensors as a good way to ride herd on the amount of water required for a green or fairway. However, Frank cautions that – even just for monitoring water needs – proper placement of the sensors is vital.

So far, Frank says, he is not aware of any golf courses that have fully automated their irrigation, relying totally on sensors. However, he is big on sensors for monitoring the turf’s water needs. In fact, the MSU team learned a thing or two, itself, about how much water it was applying.

“We learned how much we were over-watering,” Frank told superintendents at the Ohio Turfgrass Foundation’s annual meeting in Columbus. Since their research plots are very heavily monitored and controlled, this was a surprising revelation.

“If you ever get to the point where you use sensors to control and not just monitor your irrigation, keep in mind that placement is a key issue,” he continued.

“If your sensor sits at three inches deep and the root zone extends down only two and a half inches, your data are meaningless to the turf,” he points out.

Most sensors monitor moisture, temperature and salinity. If the sensor is set to 12 percent, it will try to maintain soil moisture at that level. But remember that the system may slightly over-water to get the water level where it needs to be on a particular green. Especially on Poa, that difference might require maximum irrigation run times at night.