SIGNIFICANCE OF ANCIENT AGRICULTURAL SOILS FOR LONG-TERM AGRONOMIC STUDIES AND SUSTAINABLE AGRICULTURE RESEARCH

For agriculture to be sustainable, it must maintain productivity and environmental conservation for many generations. Long-term field studies are essential to the development of sustainable agricultural systems because they are a primary source of scientific knowledge about agronomic conditions during long periods of farming. In addition to knowledge generated by monitoring fields during the past century, there is also a need for information on a longer time scale. Ancient agricultural sites are potential sources of information about agronomic conditions after centuries to millennia of use. Although only the end results of farming can be directly observed at these sites, partial reconstruction of the agricultural history is possible. Studies in Peru and New Mexico, in which ancient agricultural soils were evaluated relative to uncultivated soils, are presented here to illustrate the potential of ancient agricultural sites to extend the time perspective of long-term research on soil tilth, fertility, and conservation. Studies of ancient agricultural sites can also contribute to ideas about land stewardship and agricultural sustainability.