Is a weather station a part of your irrigation system? If so, does it work? If it works, do you use it? If you use it, do you use it for irrigation or to help you with your IPM program? Weather stations are one of the oldest sensor technologies we have on golf courses, yet they may have outlived their usefulness and worth?
Weather stations estimate the evapotranspiration (ET) used by the turf over a 24-hour period to aid in scheduling irrigation or, if desired, automatically change irrigation schedules. Normally, there is one weather station for an 18-hole course, but some 18-hole courses and many multiple golf course properties have multiple weather stations. They measure the six parameters required to calculate ET: wind speed and direction; solar radiation; temperature; relative humidity; and rainfall. One of the frustrating things was even though you had the six sensors you could not access the sensors to provide individual measurements of those parameters. Instead, all you could get was ET. For example, this is why you see many weather stations with two rain buckets – one to calculate the ET and the other to provide a rainfall measurement.
Through the years, weather stations have had their issues. Hard-wired stations never worked over long periods of time. Power needed to be found and they require 120 volts, not the 220 volts common on the vast majority of golf course field controller power systems. As a result, in the last decade solar-powered stations have begun to communicate with the central via radio, eliminating wiring.
Until recently, irrigation equipment manufacturers had one weather station option for their control system and it was expensive. Over the years I’ve met few superintendents who automatically change their schedules based on the weather station. That makes them pretty smart. I have met many who look at the ET number the weather station generates and enter it into their scheduling methodology as a variable to consider.
I have met even more superintendents who don’t use their weather station because it provides misinformation or has stopped working, most likely due to lack of maintenance. Yes, weather stations require regular maintenance if they are to provide accurate information. They also should be grounded.
Granted, not providing accurate information was not always the weather station’s fault. If the weather station is installed on the maintenance facility roof it will read the ET for the maintenance facility roof, not the turf.
So why are weather stations becoming obsolete? One reason is new technologies lower costs that give more specific information than that of the traditional weather station. These include portable soil-moisture probes or below-grade, soil-moisture sensors. These technologies provide very specific water availability data as opposed to a calculated estimate. One superintendent recently told me he thinks locally and prefers to water by feel as opposed to ET, and if he used ET then his greens would not be as firm as golfers expect.
Additionally, the importance of a weather station is further negated with the proliferation of all the local content on the web. Rain gauges are inexpensive and they are the single biggest benefit to pause/cancel irrigation cycles – providing your somewhere where it rains. The amount of information gathered from the web is much less expensive and can give you as much or even more data than you need. Certainly there are weather sensors available that provide lots of parameters in addition to the six needed, but not a whole lot that provide ET. But again, these days this doesn’t seem to be a big deal as not many people are using ET. Superintendents are using other means to fine tune their irrigation schedules and, in most cases, they have better results.
The irrigation design trend is to exclude the weather station. If you are considering a new weather station or repairing an existing one, then you may want to first decide if it’s worth the investment and whether it still fits into your management strategy. Then, investigate the new technologies available to assist you with irrigation scheduling.