Abstract: The moisture content of the soil in each of a number of areas is maintained between predetermined wet and dry thresholds by a control having circuits operative in response to detected thresholds through contacts inserted in the soil to effect the opening and closing of a valve in the conduit by which water is delivered to that area. Typically a number of conduits are connected directly or through junctions to a common water supply and where that supply is pump controlled, the control for each conduit includes circuitry that enables a switch in the pump motor circuit to be closed whenever the valve operated by that control is open.