Model for management of an on-demand irrigation network based on irrigation scheduling of crops to minimize energy use (Part II): Financial impact of regulated deficit irrigation

The aim of the GREDRIP model (Part I) is to provide centralized management of an irrigation network, with a minimum energy cost at the pumping station, based on irrigation scheduling to guarantee crop water requirements in the irrigation network. In this paper, the combined use of GREDRIP and MOPECO models was used to improve water and energy consumption by applying Regulated Deficit Irrigation (RDI) to crops in the SORETA irrigation network (Albacete, Spain) for crop distribution and weather conditions during irrigation seasons 2015 and 2016. The MOPECO model was used to determine irrigation schedules and to estimate the relationship between irrigated crop yield and net water applied. The aim of this paper was to validate the GREDRIP model under different water demand conditions, and to study the financial impact on the irrigation network under drought conditions. Results show that GREDRIP is suitable for management of an irrigation network such as SORETA, reducing the energy cost by 32%, in comparison with the current situation. The financial analysis carried out shows that a 25% reduction in water consumption would have reduced the gross margin (GM) in SORETA by 30% (from 1199 to 839 (sic) ha(-1)) in 2015 and 16% (from 914 to 771 (sic) ha(-1)) in 2016, when RDI is applied to all crops. When RDI is only applied to less profitable crops (extensive herbaceous but not horticultural crops such as onion or garlic), a GM reduction of only 9% is obtained under 2015 and 2016 conditions, respectively. The water saved could be used for other purposes, such as increasing the crop area with higher GM, or simply to recharge the aquifer at risk of overexploitation, which would greatly benefit the environment. The combined use of GREDRIP and MOPECO can help to improve water and energy management in irrigation networks through crop irrigation scheduling. This can increase the profitability of agriculture by analyzing the financial effects of different irrigation management systems.