Abstract: A horticultural system which consists of a container for a plant which sits within a reservoir for irrigation liquid to allow flow of irrigation liquid between the container and reservoir. Irrigation liquid may be to said container and/or said reservoir. Sensor means are located in said reservoir to measure the volume of liquid in said reservoir and a second sensor means in said reservoir measures the electrical conductivity of liquid in said reservoir. A controller is programmed to control the supply of irrigation liquid to the container and/or reservoir using the measurement of liquid height and electrical conductivity in said reservoir.

Abstract: A soil moisture sensor which includes a processor to derive soil moisture values and a memory store associated with said processor to store measured values on a periodic basis, wherein the processor scales the stored moisture values to establish a moisture range for the sensor that can be used to calibrate each new reading. The sensor includes a capacitive sensor. In one embodiment the processor measures the capacitance at a single frequency and also measures the phase and amplitude to derive measures of soil impedance due to moisture content and conductivity. In another embodiment the soil sensor capacitor is part of a resonant circuit and the resonant frequency of the circuit is measured as an indication of soil moisture. The sensor is constructed on a single substrate, which also functions as its own insertion stake into the soil.