Observer effect

The "observer effect", a theory that suggests simply observing or measuring a phenomenon changes the phenomenon, is not a common occurrance in turfgrass management research. However, a recent trial conducted by Dr Doug Karcher (@uarkturf on Twitter), University of Arkansas, illustrates the observer effect in a wetting agent trial.

The green patches in the associated photograph are the locations where the TDR soil moisture probes were inserted into the grass to measure soil moisture (where the observations were made) on…