Water saving with a PLC based adaptive irrigation system

• Author(s): Shahidian, S. ; Serralheiro, R. P. ; Teixeira, J. L. ; Santos, F. L. ; Oliveira, M. R. G. ; Costa, J. L. ; Toureiro, C. ; Haie, Naim ; Machado, R. M.
• Date: 2009
• Persistent ID: http://hdl.handle.net/1822/18690
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): PLC; Irrigation; Automation; Hargreaves
• Document Type: Conference Object
• Language: English

Description

Irrigation is presently the main user of world´s fresh water. Most of it goes to irrigating small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. The dramatic development of Programmable Logic Controllers, PLCs, and their rather affordable price has made it possible to use them as stand-alone irrigation controllers. In this paper a PLC is used to adapt the daily irrigation amount to actual ETc, using a Hargreaves-Samani type equation. Once the ETc is calculated, then the PLC manages the irrigation according to the specifications given by the farmer. First year results indicate an 8% saving in irrigation water.