An increase in population quantity and community cultural diversity drives the need for the Bangka Belitung Islands Province to increase the productivity of the agricultural sector, especially rice as the main source of staple food. Not only is increasing the quantity of lowland rice production a measure of guaranteeing food security, but managing a healthy agricultural environment is also very important in achieving the sustainability target of national food security. What is unique is that the group of farmers in the rice production center of Bangka Belitung, namely Rias Village, Toboali District, South Bangka Regency, has a variety of cultures whose domicile is grouped based on ethnicity. This research was carried out to map the locus of lowland rice farmer groups based on ethnicity and describe the character of environmental management of lowland rice farming in the context of sustainable food security. The research method used was a survey of 60 rice farmers, mapping farmer group loci, and quantitative descriptive methods. The research results are depicted in a locus map of farmer groups of Bangka ethnic, Javanese, Bugis, and Sundanese ethnic groups. It was found that differences in the environmental management characteristics of lowland rice farming include: the selection of rice varieties, different agricultural practices, such as the use of organic fertilizer, traditional-based irrigation, crop rotation, cooperation patterns, and land ownership systems.