An innovative remote sensing based reference evapotranspiration method to support irrigation water management under semi-arid conditions

In order to evaluate the utility of the MA + LSE approach for irrigation water management, some well-known methods for ETo assessment and the MA + LSE approach were considered for the development of irrigation schedules in ten irrigation schemes located in a semi-arid region in Southern Spain. The impact of the approach considered for ETo assessment on irrigation scheduling and on simulated yield for a maize crop was determined. Thus, MA + LSE and Hargreaves methods generated similar irrigation schedules and estimated yield to those determined by using ETo from the Penman-Monteith (PM-FAO56) approach. Thus, average seasonal irrigation volume estimated by MA + LSE was underestimated by around 2.6%, causing a yield reduction of 2.2% compared with the irrigation scheduling based on PM-FAO56. These results confirm the applicability of the MA + LSE approach, especially in areas where meteorological data are missing or inaccurate, obtaining a similar performance for irrigation water management to that of other approaches with high data requirements such as PM-FAO56.