Agricultural and residential space were integrated in prehistoric lowland Mesoamerica for productive and domestic activities to produce distinctive patterns of settlement and land use visible in the archaeological record. Ethnoarchaeological studies provide information on the behavioral component of site formation in such contexts. Contemporary residential refuse treatment and the use of infield agricultural land are examined here from a sample of farming households in the Sierra de los Tuxtlas of southern Veracruz, Mexico. A model of site structure (the House-Lot model) relates the maintenance of refuse-free (clear area) and refuse-laden (intermediate area) spaces within the house lot to household farming activities outside of the residential lot. Variation in the intensity of cultivation on infield plots is shown to correlate with variability in the size of areas within house lots. This research suggests that the distribution of prehistoric residential debris might be used to diagnose factors of ancient agriculture and settlement in contexts commonly encountered during archaeological excavation and survey.