To make radio distance any significant distance requires height, because of such things as the Fresnel Zone.

Luckily, in Australia it is a rare working farm that doesn't have a windmill (a particularly common sight in areas not served by mains water) and/or a dedicated radio tower. This is good, it will let us design a system that can have a high central node and reduce the amount of elevation required for antennas in the paddocks.

The photo shows the tower that someone will need to climb when we are ready to start extending the range of SentriFarm :-)