Some thoughts on the factors that controlled prehistoric maize production in the American Southwest with application to southwestern Colorado

• Published in: Journal of archaeological science Vol. 40; no. 7; pp. 2869 - 2880
• Main Authors: Benson, L.V., Ramsey, D.K., Stahle, D.W., Petersen, K.L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2013; Elsevier
• Subjects: America and Arctic regions; Maize agriculture; North America; Prehistory and protohistory; Southwestern Colorado; North America; United States of America; Colorado; America; Maize agriculture; Southwestern Colorado; Floor; Prehistory; Production; Agriculture; Maize
• ISSN: 0305-4403; 1095-9238
• DOI: 10.1016/j.jas.2013.03.013

In this paper, we present a model of prehistoric southwestern Colorado maize productivity. The model is based on a tree-ring reconstruction of water-year precipitation for Mesa Verde for the period A.D. 480 to 2011. Correlation of historic Mesa Verde precipitation with historic precipitation at 11 other weather stations enabled the construction of an elevation-dependent precipitation function. Prehistoric water-year precipitation values for Mesa Verde together with the elevation-dependent precipitation function allowed construction of the elevation of southwest Colorado precipitation contours for each year since A.D. 480, including the 30-cm contour, which represents the minimum amount of precipitation necessary for the production of maize and the 50-cm contour, which represents the optimum amount of precipitation necessary for the production of maize. In this paper, calculations of prehistoric maize productivity and field life for any specific elevation are also demonstrated. These calculations were performed using organic nitrogen measurements made on seven southwestern Colorado soil groups together with values of reconstructed water-year precipitation and estimations of the organic nitrogen mineralization rate. •The lower elevation limit of maize production in prehistoric southwestern Colorado is calculated.•The elevation of the lower limit of maize cultivation shifts on average 250 m.•Prehistoric Native Americans would tend to farm at relatively high elevations.