A Simple Method to Design Irrigation Rate and Duration and Improve Water Use Efficiency

Irrigated agriculture will have to increase production to meet the demand for food of the population of the world. A simple physically based method is presented that allows to determine appropriate irrigation rate and duration to avoid runoff, thus contributing to the design of efficient irrigation. The method relies on the infiltration capacity curve of the soil under interest. This curve allows determination of two important relationships: (a) maximal irrigation rate vs. irrigation dose and (b) irrigation duration versus rate. Two case studies illustrate the application of the method to adapt irrigation to the reduction of soil infiltration capacity resulting from the quality of the irrigation water (treated wastewater) or soil surface sealing. The range of irrigation rates for which duration can be estimated as the ratio between the required dose and the application rate is defined.