Dear Randle,
The sensor can only measure the humidity of the place where it is inserted but not an large area. It cannot measure the soil moisture level within a few meters of the surrounding area. However, the general humidity of the soil where sensor is inserted does not have much difference. So when inserting it, we suggest find a place which represents the average condition for your zone, not place sensor in special places, such as edges, pits, blocked places, etc.
Thanks,
Netro Support