Economic, environmental, and social sustainability of water-saving solutions for the rice sector in the Mediterranean basin

In the Mediterranean basin, rice has important economic and social implications, especially in areas where it is a staple food such as Egypt. On the other hand, the peculiar flooding conditions in which rice is traditionally grown lead to the use of huge volumes of water, as well as to the potential release of greenhouse gases and pesticides into the environment. The introduction of water-saving irrigation strategies could reduce water consumption and decrease the harmful environmental impacts while maintaining yield and rice quality. However, the environmental, economic and social sustainability of these strategies must be adequately evaluated. To explore the overall sustainability of innovative water-saving irrigation strategies, several experimental farms were selected in the main rice producer countries of the Mediterranean basin (EG, IT, TR, ES, PT) in the context of the MEDWATERICE project (https://www.medwaterice.org/). In particular, the alternative irrigation strategies compared to the wet seeding and continuous flooding (considered as the ‘reference’ irrigation in all CSs), were: alternate wetting and drying (AWD); dry seeding and delayed flooding (DFL), water input reduction after day 100 from sowing (WIR), hybrid irrigation (HYBRID), multi-nozzle sprinkler irrigation (SPRINKLER), surface drip irrigation (DRIP), and subsurface drip irrigation (SDI). A set of indicators for the quantitative assessment of the environmental and economic sustainability of the irrigation options were defined, which includes: Farm Profitability (Net Income); Labour Productivity; Productivity (Grain yield); Water Productivity; Relative Water Supply; Percolation to Groundwater; Energy Productivity; Nutrient (N, P, K) Use Efficiency; Greenhouse Gas Emission (CH4 and N2O); Environmental Potential Risk Indicator for Pesticides (EPRIP); Food Safety (Arsenic and Cadmium grain rice content). The social acceptability of the irrigation strategies was investigated through the Technology Acceptance Model (TAM) by involving rice growers of the pilot areas, barriers to the adoption of the irrigation strategies were assessed and ways to overcome them identified. The indicator set was applied to datasets collected in the experimental farms during the agricultural seasons 2019-2021, and results are being extrapolated to the irrigation district level to support water management decision makers and policy planners. The methodologies developed and the results achieved are illustrated and discussed in this paper.