Modelling water balance at the irrigated crop level to identify pathways for improving water use efficiency

In this paper, the Soil-Water-Atmosphere-Plant (SWAP) model was used in conjunction with ROSETTA, a soil hydraulic properties simulation program, to evaluate the water balance for irrigated maize crop in Finley, NSW, Australia. The authors used the soil moisture content data to calibrate the SWAP model. The result shows that the simulated soil water content agrees well with the observed data excluding some very low measured soil water content value. Through analyzing the water balance components it appears there are opportunities to save water through better irrigation scheduling and recycling of drainage water. This can be used to help improve irrigation water productivity at the crop and irrigation system levels.