Irrigation control system

[0053]FIG. 1A schematically shows an exploded view of a tensiometer 20 for measuring water matric potential in a soil, in accordance with an embodiment of the invention. FIGS. 1B-1D schematically show enlarged views of components of tensiometer 20 shown in FIG. 1A. FIG. 2 schematically shows an assembled view of tensiometer 20. For convenience of presentation, apparatus 20 is referred to as a tensiometer, even though, as shown in FIGS. 1A-1D, it optionally, does not comprise a water reservoir and apparatus for providing a measure of pressure in the reservoir.

[0054]Tensiometer 20 optionally comprises a housing 22 having first and second housing parts 30 and 50, hereinafter referred to for convenience as housing top 30 and housing bottom 50, a sealing septum 60, a hydraulic soil coupler 70 formed from a porous material and a resilient element 80.

[0055]Hydraulic coupler 70 is formed having a soil-coupling region 72 that extends outside of housing 22 when tensiometer 20 is assembled (FIG.