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Tuesday, November 21, 2006
The Archaeology of Agriculture
In recognition of the harvest festival of Thanksgiving, and the latest food-themed edition of the Four Stone Hearth blog carnival to be hosted at about.archaeology.com, I thought it might be interesting to explore agriculture in prehistory, particularly in the Maya region and northern Belize where I studied in 2004. For some reason, I find agriculture and subsistence the most interesting topic in archaeology. I was raised in a state that is known for farming, mostly of tobacco, and home to one of the top agricultural science schools in the country (NC State). Something must have clicked because a few years ago I realized I was fascinated by how ancient peoples worked the land to produce the most basic of all human necessities.
The role of subsistence in the ancient economy of the lowland Maya has a long and dynamic history, consisting of hunting and gathering, animal husbandry, and agriculture (click here to see a map). Each of these was practiced at different times and to different degrees depending on environmental or social circumstances. Extensive agriculture requires a relatively large area of land and generally refers to the use of a plot of land followed by a long fallow period where the soil is allowed to replenish itself with nutrients. While this is occurring, another plot is under cultivation until it too needs to lie fallow. Farmers eventually return to land that has been naturally replenished and the process is repeated. The type farming known as swidden, or slash-and-burn, is an example of extensive agriculture and is still practiced today in some areas.
Intensive agriculture in the lowlands is characterized by the continuous cultivation of a plot of land and short fallow periods, with some practices requiring none at all. Such practices may have occurred primarily in areas with abundant rainfall and healthy, well-drained soils, such as alluvial valleys and floodplains. This includes most of the lowlands as well as parts of Belize. The archaeological evidence for intensive agriculture can be interpreted most prominently from the ancient remains of terraces, raised fields, and irrigation as well as botanical remains. Such evidence has been collected at many sites in the central lowlands and northern Belize. The photo here is of intensive type agriculture as it is practiced today in the Maya area.
Data from several sites throughout the central lowlands and northern Belize has been interpreted as evidence of intensive agriculture. Many of these cases do not always offer clear examples that intensive practices were present or that agriculture has taken place at all. This is perhaps the result of the highly variable landscape of the region that can often mask what may or may not have been the case. It is important to examine multiple lines of evidence when investigating intensive agriculture in order to arrive at the best possible scenario, however incomplete this may be. One well-documented case of this is at the site of Pulltrouser Swamp. Pulltrouser Swamp is located in northern Belize, approximately 45 kilometers north of Lamanai and east of the New River. The area has been described as a complex of three elongated depressions that are a part of the bajo region of the eastern Yucatan Peninsula. The geography is comprised of low rolling to hilly limestone terrain that is characterized by surface and subsurface drainage.
Drainage is an important aspect of Pulltrouser Swamp and has obvious implications for intensive agriculture. Additional geomorphological research suggests that little has changed since the ancient Maya occupied the area. The component of this site that is of particular interest is the unique pattern of mounds and ditches on the landscape that have been interpreted by some as raised fields. The interpretation of this type of landscape as raised fields is based on aerial photographs and ground surveys that show irregular patterning in the landscape. Excavations yielded information on the dimensions of the mounds and ditches, soil type and stratigraphy, botanical remains, and artifacts that seemed to suggest subsistence practices were present. This data was used to interpret the ground pattern as consisting of fields and canals having cultural origins. Some dismiss the possibility that such a well-defined pattern on the landscape is the result of natural phenomena and cite inconclusive botanical evidence, including the presence of maize. In more recent studies that use similar types of data, others maintain that while northern Belize offers the earliest evidence for the development of agriculture in the lowlands, no evidence of human-constructed canal irrigation exists at Pulltrouser Swamp. Instead, it was found that the series of mounds are actually naturally elevated hummocks, or low ridge of earth, which are common in the area.
Another site in the wetlands of northern Belize that yields useful information about agriculture is San Antonio Rio Hondo. Interpreting data previously collected by Dennis Puleston west of the Hondo River on Albion Island, researchers have shown that the ancient Maya were cultivating wetlands in the area by 1000 BC and that this was occurring in conjunction with swidden farming in the uplands during the wet season. Puleston’s initial hypothesis was that two stages of field use characterized early wetland agriculture at Albion Island. Observations of stratigraphy from three pits at San Antonio suggested that sediments from the flood plain were first built up and that platforms were subsequently constructed from quarry material from the uplands (similar to what is shown in the photograph). This hypothesis was revised when viewed in light of pollen, plant macrofossil, mollusk, and soil fertility data from pits that indicated “definite agricultural activity” in other pits but not in the ones mentioned above. This is the result of low levels of organic carbon in the soil.
Further depositional analysis suggests that the natural accumulation of mollusks and other sediments resulted in what initially appeared to be artificial planting platforms. Evidence for agricultural activity at San Antonio includes pollen and plant macrofossils that indicate maize cultivation was present. Organic carbon in the soil indicates that the ancient Maya cultivated at San Antonio during the dry season. Environmental changes during the Late Preclassic and Early Classic periods caused a rise in the rivers of northern Belize and higher water tables. Dated stratigraphic material collected from Quintana Roo, Mexico and Florida has been correlated with the stratigraphy of coastal lagoons in northern Belize, indicating a large-scale change in water level. Ditching appears to have occurred at the site, possibly because of the rising water which necessitated the construction of deep, narrow trenches for draining purpose.
This is just a brief example of what archaeology can tell us about how ancient societies utilized land and water resources for subsistence purposes. There are countless examples from all over the world of ancient farming and they vary quite widely. The brief example described here of the ancient Maya in northern Belize highlights the different lines of evidence that can be used to hypothesize how and on what time scale agriculture developed and changed, often correlating such activity to natural climatic or geologic events. Incidentally, one of the readings for my theory course this week has to do with gender and food. In this post I have talked about just one line of information we can take when looking at subsistence, but there are many other aspects of food production and broader relationships that can be gained from the evidence. Christine A. Hastorf writes:
Food systems, in many ways, are the bases of societies, essential to sustenance, division of labor, control, and social symbolism. Despite our archaeological fascination with how people got their food, we must not miss the ability of food to inform us about the equally important cultural dynamics. The use of botanical data has its limitations, but it also has important potential to view social and political relations. Paleoethnobotanical data should not be confined only to what people ate, but should help in investigating broader social and political relationships.
Hastorf, Christine A. (1991) Gender, Space, and Food in Prehistory from Contemporary Archaeology in Theory (ed. Preucel and Hodder)
Posted by Will at November 21, 2006 08:48 AM in