Substantial areas of inland wetlands have been transformed into croplands globally. Seasonal flooding in rice fields, especially during early summer, is well known to provide alternative habitats for species dependent on wetlands and aquatic environments. However, it remains unclear whether temporal flooding in other non-rice croplands, such as wheat fields, can serve a similar function, and whether landscape features influence biodiversity in these fields. Here, we focused on the farming policy of short-term flooding in non-rice croplands in central Hokkaido, Japan, where farmers flooded their croplands for approximately one month after harvest to receive subsidies. We investigated the effects of the flooding by examining the diversity of a whole avian community and the major functional groups including waterbirds and globally declining migratory shorebirds in flooded non-rice croplands and conventional dry croplands from flooding to after-dried-out periods. The surveys were conducted in the Ishikari flat plain from August to October in 2023 and 2024, coinciding with southward migration. We found that species richness and abundance of waterbirds and shorebirds were significantly higher in the flooded croplands than in conventional dry croplands and dried-out croplands after flooding. In contrast, terrestrial bird abundance and species richness were not significantly different between the land use types in both periods. Moreover, waterbird and shorebird abundance and species richness were significantly higher in the larger flooded croplands and decreased with the progressing season. This suggests that their stopover habitat utilization might be the most intensive in larger wetlands and during the peak of migration. These results emphasize that short-term flooding even in non-rice fields is effective for serving artificial habitats to migrating waterbirds, potentially contributing to expanding waterbird conservation to broader regions and periods in which rice has not been growing. In the final part of the presentation, we presented the latest updates on the farming policy in Japan and discussed how to efficiently manage flooding to enhance wetland biodiversity conservation.