In this paper it is proposed to use crop genotype selection and farming region control for irrigation optimization and improving water sustainability. A tool is developed for offering irrigation demand and harvest amount information for three dimensional scenarios: diverse genotypes, multiple farming regions, and a long timeframe. A preliminary study and analysis are carried out on a crop sunflower with 20 genotypes, 25 European farming regions, and over 150 years, in order to demonstrate the proposition and to test the tool. This study results in a methodology usable in future research, to study interactions between irrigation, crop genotypes and the environment.