In the ongoing debate about the role of agriculture in the development and decline of Classic (250–950 CE) Maya lowland societies, the archaeological site of Río Bec has a special place. It is one of the few settlements in which, years before the use of LiDAR to survey the Yucatán peninsula, a multi-scalar geoarchaeological study (Río Bec Project 1, 2002–2010) allowed us to define a field system—that is, landed domains of distinct fields organized around their local networks of household units. The dimensions of the fields, their correlation to the size of their corresponding households, and their long period of use (200 years, 700–900 CE), during Río Bec’s apogee, raise questions about the fundamental issues of land use practices (intensification, diversification, and specialization) and their sustainability over what was a relatively long period. Those issues are at the heart of a new research program at Río Bec, which we began in 2019, combining an archaeobotanical approach with land use and settlement pattern modeling, ultimately aimed at correlating local agricultural production with demography (Río Bec Project 2, 2019–2022). Based on the knowledge of field and settlement systems in their environment that we accumulated during our past research, the paper starts with a description of the field system in one sector of the Río Bec site, then focuses on the diversity of its plots on the household scale and proceeds to discuss the preliminary correlation that can be established between agricultural intensification and demography at Río Bec at the neighborhood scale and the settlement scale.