Underground irrigation system for football pitch - has water level sensors and ohmmeter to monitor nutrient requirements with perforated drain pipes housed in covered gravel-filled trenches

摘要

An enclosure, such as a football pitch, has an impermeable liner (12). A series of trenches (9) are filled with gravel and have perforated drain tubes (8). A filter covers each trench, and a pair of tubes (8) in adjacent trenches and joined and connected by pipe (16) to an overflow chamber for drainage via pipe (19). A perforated tube (22) is fed with water and, if necessary, nutrients from a control station. Sensors detect variation of the water level (21) to cause water to be supplied through tubes (22) when the level is low. Ohmmeters buried in the ground measure conductivity so that the need for liquid nutrient can be gauged and the grass can be fed in via tubes (22).