We recently had two demo soil sensors installed in our nursery outside of our shop to see how we could implement them in our day to day irrigation activities. So far it has been interesting comparing the data from our weather station to the data from the soil sensors. I have printed the graphs from March 1st to the 15th and you can definitely tell where the spikes in rainfall have occurred but more importantly the soil temperature graph definitely shows a gradual increase in the two week period.
The Toro Turf Guard Sensors are designed to give readings at two levels. The upper level which is set about 2" below the surface and the lower sensors are 6" below that. When you look at the moisture graph you will see two lines. The lower line is actually the upper sensor and the upper line is of course the lower. Our nursery is only built on about 8" of sand so you will naturally see a higher amount of moisture accumulate there before it drains away with the subgrade. It appears to be pretty steady around 45 to 50%. What we would normally like to see would be a number around 25 to 30%. On our regular greens, which are built on 12" of sand, that lower number would be much closer to that. What I am excited about seeing is how well the greens are draining from the surface. As you look at the rainfall graph above and correlate it to the moisture levels, you will notice how steep the line is going up and back down. This tells me that the surface is draining very quickly. This winter we decided to use Revolution by Aquatrols throughout the winter to see if we could keep the surfaces of the green better drained and what I see so far it looks like it is beneficial. Revolution helps insure balanced moisture levels throughout the root zone in dry and wet conditions. I must admit that this is not a scientific trial since we didn't have a check plot but the data sure looks good to me.
We are looking forward to watching the data this summer. We hope to be able to get a closer look at what is happening below the surface of the green and avoid over watering.