Modeling Agricultural Production Strategies in the Northern Rio Grande Valley, New Mexico Cynthia L. Herhahn 1 and J. Brett Hill 2 Diversification in agricultural techniques is a common strategy of risk mini- mization in nonindustrial societies. However, attribution of suboptimal behav- ior to risk minimization without consideration of the structure of risk and its environmental context obscures the complexity of agricultural decision -making. The productive potential of a prehistoric agricultural system that includes flood- water and dry farming and stream irrigation is modeled using Geographic In- formation System (GIS) analysis to evaluate whether diversification occurred as a response to population pressure or as a risk buffering strategy. The esti- mated productive potential of floodwater and irrigation farming is sufficient to have supported the estimated local population, suggesting that risk buffering is a more likely explanation. Floodwater farming and stream irrigation form a dual strategy that is effective at reducing risk. However, the potential of dry farming for subsistence production is insufficient for buffering more than a 2% productive shortfall. We propose that, within this generally risk-averse econ- omy, dry farming was oriented toward the production of nonsubsistence crops such as cotton. KEY WORDS: risk; diversification; geographic information system; Southwestern prehistory; population pressure. INTRODUCTION Arid-lands agriculture is often characterized by diversification in agri- cultural strategies, both in field location and technology. Explanations for Human Ecology, Vol. 26, No. 3, 1998 469 0300-7839/98/0900-0469$15.00/0 Ó 1998 Plenum Publishing Corporation 1 Department of Anthropology, University of California, Santa Barbara, California 93106-3210; e-mail: herhahn@sscf.ucsb.edu 2 Department of Anthropology, Arizona State University, Tempe, Arizona 85287-2402; e-mail: asjbh@asuvm.inre.asu.edu