Status and perspectives for rice irrigation in the Mediterranean Basin

Abstract

Abstract In the Mediterranean basin, rice is cultivated in approximately 1,000,000 hectares. The most important rice-producing countries in the region are Egypt, Italy, Türkiye and Spain. In all these areas, rice is traditionally cultivated under continuous flooding, requiring larger irrigation water volumes compared to non-ponded crops. In the framework of the MEDWATERICE project (https://www.medwaterice.org/), innovative irrigation methods to reduce irrigation water use and other rice environmental impacts were experimented and benchmarked to the traditional wet-seeding and continuous flooding (WFL) in seven case studies (CSs) representative of different rice agroecosystems in five Mediterranean countries. The most promising irrigation options for each CS were selected with the support of local Stake-Holder Panels, and tailored to site-specific conditions. Alternate wetting and drying (AWD), dry-seeding and delayed flooding (DFL), reduction of irrigation discharge input/output (WIR), hybrid irrigation (HYBRID), sprinkler irrigation (SPRINKLER), surface drip irrigation (DRIP) and subsurface drip irrigation (SDI) were investigated. Results suggest that AWD, DFL and WIR, which are flooding techniques rather simple to implement, might be sound alternatives to WFL leading to an increase in Water Productivity (WP) and safeguarding the yield production. Both SPRINKLER and HYBRID resulted in an increase in WP of about 50% while maintaining or increasing the yield. DRIP and SDI showed a great potential in reducing water use, increasing WP up to 260%; however, yield may sometimes be notably reduced. Nevertheless, for each technique and in particular for localized irrigation methods, site-specific conditions must be carefully evaluated to properly select, design and manage irrigation strategies.