Conference Agenda

The PROMEDRICE project aims to develop and promote site‑specific agricultural practices that reduce soil and water pollution, while maintaining or improv-ing productivity and water‑use efficiency in Mediterranean rice‑based agroecosystems. Building on the findings of the MEDWATERICE project, which demonstrated the fea-sibility of innovative irrigation strategies that reduce water use without affecting yields, PROMEDRICE takes this approach further to address broader environmental chal-lenges.
Between 2024 and 2025, monitoring and experimental activities were conducted in six Mediterranean countries, at both farm and irrigation district scales. The project iden-tified the main constraints affecting soil and water quality by compiling and updating existing information with experimental results. Key issues included soil salinisation as well as nitrate and pesticide contamination of surface and groundwater. To address these challenges, site‑specific mitigation strategies were implemented to assess their technical, environmental and social impacts.
In many of the study areas, best management practices were scaled to district and regional levels using tailored modelling approaches. These approaches provided tools to assess the impacts of alternative rice farming practices on the mid-to long-term sus-tainability of Mediterranean rice-based agroecosystems.

Rice irrigation strategies affect multiple ecosystem services that are difficult to compare because they rely on different metrics and priorities. A methodological decision-support workflow is presented, integrating expert-derived weights with literature-based indicators to produce a comparable assessment of irrigation options in rice paddies.

A structured catalogue of ecosystem services (provisioning, regulating, supporting and cultural) is first defined. Service importance is elicited through expert judgement using the Analytic Hierarchy Process (AHP) to derive priority weights; when interdependencies among services are relevant, the approach is extended to the Analytic Network Process (ANP) to obtain a weight vector accounting for network effects.

Each ecosystem service is quantified through measurable indicators selected from the scientific literature and adapted to the local context. Indicators are harmonized and aggregated using AHP–ANP-derived weights to produce comparable ecosystem-service profiles and integrated scores for management options. The framework is being implemented across multiple case studies; to demonstrate its application, it is shown here for the Lomellina rice district (Italy), comparing water seeding with continuous flooding, dry seeding with delayed flooding and alternate wetting and drying.

Overall, the proposed approach provides a transferable pathway from expert judgement and evidence-based indicators to an interpretable synthesis of ecosystem-service trade-offs for irrigation decision-making.

Sustainable water management in Mediterranean rice systems must balance productivity and environmental protection. Traditional continuous flooding limits nitrate leaching through denitrification, but the transition toward water-saving irrigation practices (dry seeding, turn-based irrigation) may affect nitrogen dynamics and groundwater quality. This study investigates spatially varying nitrate concentrations and the drivers of nitrate distribution in the phreatic aquifer in the Lomellina district (Northern Italy), one of Europe’s most important rice-growing areas. Nitrate concentration was measured in groundwater, and a geospatial database of 102 environmental and anthropogenic variables was developed. Multivariate generalized linear regression models were implemented to quantify relationships between the selected variables and nitrate concentrations. Based on the results, we identified groundwater table depth, groundwater flow velocity, vertical hydraulic conductivity, soil type, and soil protective capacity as key determinants. The study was carried out in the context of the projects: i) "Applicazione di metodi di statistica spaziale per la valutazione della vulnerabilità e disponibilità della risorsa idrica sotterranea in diversi contesti idrogeologici", funded by the Piano di Sostegno alla Ricerca (PSR Linea 4) by the University of Milan, and ii) “PROMEDRICE project (https://promedrice.org/; PRIMA-Section2-2022)” funded, for the Italian partners, by MUR (Italian Ministry of University and Research).

In rice-growing areas, irrigation efficiency is linked to groundwater levels, which regulate percolation in fields and canals, as well as discharge flows from springs and in watercourses. In Agricultural Managed Aquifer Recharge (Ag-MAR), fields are intentionally flooded and water is allowed to circulate in channel networks to recharge aquifers. Quantifying ag-MAR benefits remain challenging due to the complex surface-subsurface water dynamics involved, requiring advanced numerical modelling. This study presents a modelling framework for the Lomellina region in northern Italy (125.000 ha, 60.000 ha cropped with rice), where traditional wet seeding and continuous flooding has recently been replaced by dry seeding and delayed flooding or turned-based irrigation. This has led to lower groundwater levels and increased irrigation demand during the central months of the irrigation season. The framework combines QGIS-SWAP-Paddy, a new modelling tool that estimates irrigation demand and percolation rates in agricultural areas (agricultural fields and channel networks), with MODFLOW-6, which models groundwater flow. This integrated approach enables the evaluation of the impact of different rice irrigation strategies, including Alternate Wetting and Drying (AWD), and Ag-MAR interventions. The study is part of PROMEDRICE (https://promedrice.org/; PRIMA‑Section2–2022), funded for the Italian partners by the Italian Ministry of University and Research (MUR).

Soil salinity in Mediterranean rice fields is traditionally managed via wet seeding, continuous flooding and runoff to leach salts. However, recurrent water scarcity has forced the adoption of water-saving practices, such as the combination of dry seeding, early irrigation cut-off, and elimination of runoff (DENR). While efficient, implementing DENR in areas like Baix Ter (Spain) can exacerbate salinity in salt-affected soils and reduce yields. The Baix Ter rice district was monitored under the PROMEDRICE project (2024–2025) during a water-scarcity period. DENR was applied in the whole district, although some salt-affected fields remained fallow in 2024. The district was divided into six hydrologic units based on soil maps and topography. Water usage was monitored in one comercial field per unit. Soil electrical conductivity (EC) was measured biannually at 13 sites, while sensors tracked apparent EC in three units. Results showed high spatial variability (EC from <2 to 16 dS m^-1), demonstrating that water-saving impacts on salinity dynamics are highly site-specific. Higher yields in 2025 compared to 2024 suggest that salinity and water stress limited productivity during severe water scarcity. These results underline the necessity of site-adapted salinity management when implementing water-saving irrigation in Mediterranean rice systems under increasing climate pressure.