Mole is based on a new sensor concept. The device consists of an underground LoRa transceiver which transmits radiowaves to a buried collector. From measurements of the electromagnetic loss, soil moisture estimates can be retrieved if soil type/texture is well known. The transceiver also embeds the communication capability: a concentrator, located onboard a UAV, will connect to the Internet. The cost of the solution is in the order of 10-30% wrt traditional approaches.