Automatic Irrigation Scheduling System (AISSUM): Principles and Applications

Irrigation scheduling, which is used to determine the frequency and dosage of irrigation applications, is required to optimize water use while at the same time maximizing crop yield and farm profit. This paper describes the broad principles and applications of a computer-assisted irrigation scheduling system, namely AISSUM (Automatic Irrigation Scheduling System of the University of Montréal). AISSUM is user-friendly and has the potential for optimizing water use and enhancing crop production. AISSUM is based on the water-balance approach to irrigation scheduling. The requisite weather and soil data are collected by a solar-powered, portable micrometeorological system (SEWBS). Crop evapotranspiration (ET) is calculated using a customized software package, EDA. Irrigation scheduling is performed by the software package AIS.IRRIG. The test results for AISSUM for an okra crop in Trinidad and a raspberry field in Québec are presented. In addition to providing real-time estimates of irrigation scheduling, AISSUM gives superior results when compared to the cycle method.