Subsurface clay pipe irrigation for increasing water use productivity

Details of reduced water consumption, increased yield and water use productivity are described for a simple and efficient subsurface clay pipe systems used for irrigation over a period of four years. Clay pipes to provide an appropriate discharge are combined with a polyethylene injector network to deliver water. The method uses local materials and operates at low-pressure head. Therefore, it is useful for irrigation of orchards, vegetables and greenhouses. This system had been used for centuries in dry areas of Iran, such as Yazd and Ardakan, for production of vegetables and some annual crops. Mechanization and standardization of this irrigation system is a very important step for improving of water use productivity in Iran. Results emphasise the significant differences between surface and subsurface micro-irrigation systems. In addition there are significant differences between subsurface drip and subsurface clay pipe irrigation methods. Water use, yield and water use productivity of the subsurface clay pipe irrigation were found to be superior to the subsurface drip irrigation, as well much better than the surface drip irrigation methods.