Assessing farming practices that benefit biodiversity conservation in rice fields: Past achievements and future challenges

Abstract

To clarify the wildlife benefits of farming practices that aim to conserve biodiversity in Japanese rice fields, we reviewed three previous studies. First, in a project commissioned by the Ministry of Agriculture, Forestry and Fisheries, a nationwide field survey revealed that the species richness and abundance of multiple taxa (plants, invertebrates, frogs, and waterbirds) were higher in organic fields than in conventional fields. Second, a national survey conducted by the Ministry of Agriculture, Forestry and Fisheries revealed that the biodiversity score calculated from the abundances of several invertebrate and frog species increased with organic farming, winter flooding, and integrated pest management. Third, our systematic review of individual case studies showed that benefits differ according to both the farming practice type (e.g., organic farming, winter flooding, earthen-ditch installation, and biotopes) and taxonomic group. Many of these studies were evaluated on a small (single field) spatial scale, and thus understanding of the effects of farming practices on the population or community level was limited. Based on these results, we discuss future directions for integrating scientific knowledge in wildlife-friendly farming in rice fields.