Gardens of Prehistory: The Archaeology of Settlement Agriculture in Greater Mesoamerica

10. Prehistoric Intrasettlement Land Use and Residual Soil Phosphate Levels in the Upper Belize Valley, Central America

Figure 9-5. Contemporary Salvadoran Farmers with Digging Sticks (Zapotitiln Valley, 1978). It is common practice in highland Central America today to drop several maize kernels in a single hole during planting. Stone-weighted digging sticks may have been used at the Ceren site to enable placement of seeds at sufficient depth so that the nutrient-rich Preclassic clay underlying Jlopango tierra bll7llCl1 could be tapped. Z IE R In the absence of irrigation, it is almost certain that the young plants in Test Pit 2 represent wet-season agriculture. Contemporary farmers in EI Salvador plant corn at the beginning of the wet season, at about the time of the first rain. This event usually occurs in early to mid-May. Young plants with stalk diameters equivalent to those in the Ceren field can be expected within a few weeks of planting. It has therefore been estimated that the Laguna Caldera eruption occurred sometime in Mayor June and more likely the latter month (Zier 1980; Sheets 1989). EARLY CLASSIC PERIOD AGRICULTURE IN A POSTERUPTION ENVIRONMENT The Ceren site documents occupation of a marginal agricultural environment during the Early Classic period. The demographic implications of raised-field agriculture in nutrient-poor soils seem quite clear: that reoccupation of the region following the Ilopango disaster occurred at least in part as a response to population pressure elsewhere . The local depositional characteristics of the unweathered, nutrient-poor tierra blanca within the Zapotitan Valley at the time that it was reinhabited undoubtedly dictated the manner in which reoccupation took place. It is probable that the first agriculturalists settled in the hilly areas of the valley margins, where water erosion had stripped off or greatly reduced the depth of the tierra blanca mantle. Erosion in these areas facilitated access to the older, preeruption soils and would also have led to relatively early regeneration of native vegetation. The northern and eastern valley margins, which include the Ceren site vicinity, were most suitable to early habitation because slopes are not very steep. Other areas, particularly the foothills of the Balsam Range on the south side of the valley, are extremely rugged. They are sparsely inhabited today and are suitable only for coffee production. Archaeological data suggest that the Balsam Range foothills were hunted prehistorically but not farmed (Black 1983). The earliest incursions into the valley floor would have occurred after establishment of the valley margins and probably followed major watercourses such as the Rio Sucio and its tributaries. Riparian zones associated with these streams may have experienced erosional strip230 RAISED-FIELD AGRICULTURE ping of tierra blanca due to seasonal flooding. The remainder of the valley floor was subsequently reoccupied as the vast tierra blanca deposit weathered in situ into a productive agricultural soil. This soil eventually sustained a large Late Classic resident population (Black 1979, 1983; Zier 1981). Excavation, testing, and remote sensing data from Ceren suggest a prehistoric pattern of spaced residential units with intermediate areas utilized for crop production. Using information about the Ceren site that was available at the time, Sheets (1982:113-14) developed estimates of plant productivity relative to available agricultural space and concluded that the quantities of maize grown in the Ceren fields would have been inadequate to sustain families occupying the houses for a year. New information about the site has since been unearthed. It is now known that clusters of four maize plants, rather than individual plants, were grown at Ceren; however, the amount of space available to each household is even less than the one-third hectare originally estimated by Sheets. His overall conclusions appear to be valid yet. Sheets (1982:114) notes, for example, that at Todos Santos in the Guatemalan highlands, a family of five requires about 1.2 hectares to produce maize sufficient in quantity to satisfy annual needs. Logically, supplementary food sources would have been required at Ceren. A pattern of regional settlement in which early occupation focused on the valley margins is again identified as adaptively advantageous, these areas affording access to the greatest range of nondomesticated food resources. Only the use of seed crops is clearly documented at Ceren. In addition to maize plants found in situ in the field were small beans in two storage pots located within one residential structure (Zier 1983:131). Seeds of chile peppers and uhushte, a wild edible plant, also have been tentatively identified on the basis of recent work at Ceren (Sheets and...