Intelligent Control of Capillary Irrigation System for Water-saving Cultivation

Subsurface micro irrigation techniques such as capillary irrigation has long been proven to provide higher water saving for cultivation. Advancement of the capillary irrigation system has been made by using a high capillarity fibrous medium to transfer water directly to the rooting zone of plant. Wicking of water through the fibrous medium depends on the distance from a water source which known as water supply depth. The irrigation system is being managed by manipulating the water supply depth. However it is difficult to determine the optimum depth due to the dynamic water requirement which depends on the plant growth stage and climatic change. In this study an adaptive method was introduced to manage the irrigation system based on water balance and energy balance model. Using the estimated data the optimum depth was determined by using fuzzy expert system. An experimental set-up was built using the fibrous-capillary irrigation system that allowed the change of water supply depth in real time. The optimum water supply depth obtained based on the adaptive method was analyzed based on water usage and plant yield which showed significant amount of water saving. The results suggested the feasibility of the water and energy control model as an irrigation scheduling index for the fibrous-capillary irrigation system.