Using Maize Productivity Indices to Characterize and Compare Potential Maize Productivity Across Mississippian Sites

Maize productivity indices, used by the Natural Resources Conservation Service to distinguish soils across the United Sates based on their potential maize yields, were identified for soils within an 8 km-radius of 28 Mississippian sites/site complexes. Across all sites, 96,380 ha are classified as highly productive and 166,889 ha as moderately productive for maize. Productivity varied greatly across sites and site complexes, with the Cahokia Uplands having the largest amount of highly productive soils (27,336 ha).  Moundville, in contrast, had no soils classified as highly productive. Productivity indices were higher in sites located in Illinois, Missouri, Indiana, and Kentucky and lower in states farther south: Tennessee, Arkansas, Alabama, and Mississippi.  Both the quantity of highly productive soils and their unequal distribution have important implications for how we characterize and evaluate the role of maize in Mississippian communities.