"Stepping"

With moisture sensors down to 40 inches, we can monitor root growth and watch water uptake at those depths.  We do this by watching "stepping" in the soil moisture graphs.  In our demo probe, we can see that the roots are drawing water at the four inch depth and we can see some slight stepping at the eight and twelve inch depths.

This is the same graph, but with the stepping highlighted in red.  Each step is the crop drawing the water level down.  The corn in this part of the field is currently around V5 and we should see these steps get bigger and see them at deeper depths as the roots grow deeper and begin drawing more water for the bigger plant.  As the soil water level goes down, you might see the steps get shallower or eventually level off.  This indicates that the moisture level is low enough at that depth the plant can no longer draw water from the soil. 

This is a graph from a previous year.  You can see that as the season progressed, that  roots were drawing water all the way down to the 40 inch sensor.  This graph also shows the stacked view of the soil moisture graph.  This view organizes the sensors by depth.  It is useful in seeing how deep the roots are and how deep water is soaking in after a rain or irrigation event.