SUSTAINABLE AND ENVIRONMENTAL FRIENDLY RICE CULTIVATION SYSTEMS IN EUROPE.

FACCE ERA-NET+ GreenRice

In Europe, rice (467 000 ha) is gown under permanently flooded (PF) conditions using irrigation waters of major rivers. Climate change, which already induces decrease in the river flows, is a major challenge in the production systems used to grow rice that needs also to cope with the increased demand of rice supply (net deficit of 0.86 Mt in Europe). Rice yields under existing production practices are therefore threatened by scarcer water availability and more frequent extreme weather events. In addition, PF rice fields emit greenhouse gases (GHG), mainly methane (CH4), that have a very strong warming potential. Alternative wetting and drying (AWD) is a system in which irrigation is applied to obtain 2 to 5 cm of field water depth. After a certain number of days (normally 2 to 7), when the field reaches a threshold of soil water potential, water is applied again. It is considered that water input can be reduced by 15-30% with no loss in yield and that GHG emissions will be reduced by up to 48 %. AWDS represents therefore an interesting alternative for European rice production. The objective of GreenRice is to test AWDS in three regions of Italy, Spain and France that are representative of the diversity of European rice growing areas. In the deltaic areas (Spain and France), rice and natural wetlands protected through natural regional parks are interdependent. We will evaluate the implications of shifting from a PF to an AWD system on rice environment and productivity. Changes on environmental elements such as water consumption, soil salinity, soil microbial community, GHG emission, soil chemistry, and arbuscular mycorrhizal (AM) colonization will be monitored. We will identify varieties that maintain their productivity under AWDS through whole genome association mapping of a large panel of temperate varieties and will set the bases for marker-aided breeding using genomic selection to predict the values of additional breeding lines. We will investigate traits determining adaptation to AWDS such as root development, AM colonisation, salinity tolerance and resistance to nematodes using the same large panel of European genotypes; AM symbiosis impact on biotic stress (blast) alleviation will be tested. An extensive gene expression study will identify the root types and genes of major importance in transport process and the degree to which they are affected by AWDS. The role of plant traits and the soil microbial community in modulating C, N and GHG cycling will be investigated in controlled environment studies. The results obtained will be disseminated to the local stakeholders (farmers and natural parks and spaces, mainly) and to the scientific community (through web site, database and publications). Scientists specialized in molecular genetics, functional genomics, phytopathology, agronomy, ecology, and bioinformatics from 7 institutions of 4 countries will be involved.