Development and application of methods used to source prehistoric Southwestern maize: a review

Archaeological cobs free of mineral contaminants should be used to source the soils in which they were grown. Mineral contaminants often contain much higher concentrations of metals than vegetal materials and can alter a cob’s apparent metal and heavy-isotope content. Cleaning a cob via immersion in an acid solution for more than a few minutes will result in the incongruent and sometimes complete leaching of metals, including strontium (Sr), from the cob. When using ⁸⁷Sr/⁸⁶Sr to determine the location of potential agriculture fields, it is best to either integrate several depth-integrated soil samples or to integrate several vegetation samples from individual fields. Biologically labile Sr in semi-arid Southwestern soils largely originates from eolian source or sources and usually is not derived from underlying bedrock. Existing Sr-isotope data indicate that archaeological cobs from Aztec Ruins came from either the Mesa Verde-McElmo Dome or Totah areas, that Pueblo Bonito and Chetro Ketl cobs, from Chaco Canyon that predate A.D. 1130, probably came from the Rio Chaco corridor, and that cobs from Chaco Canyon, that postdate A.D. 1130, probably came from either the Totah or Zuni areas.     

Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 2: The Chaco Halo, Mesa Verde, Pajarito Plateau/Bandelier, and Zuni Archaeological Regions

Chemical and nutrient analyses of 471 soil samples from 161 sites within four archaeological regions (Pajarito Plateau/Bandelier, Zuni, Mesa Verde, and the Chaco Halo) were combined with historical climate data in order to evaluate the agricultural productivity of each region. In addition, maize productivity and field-life calculations were performed using organic-nitrogen (N) values from the upper 50 cm of soil in each region and a range (1?C3%/year) of N-mineralization rates. The end-member values of this range were assumed representative of dry and wet climate states. With respect to precipitation and heat, the Pajarito Plateau area has excellent agricultural potential; the agricultural potentials of the Zuni and Mesa Verde regions are good; and the agricultural potential of the Chaco Halo is poor. Calculations of N mineralization and field life indicate that Morfield Valley in Mesa Verde should be able to provide 10 bu/ac of maize for decades (without the addition of N) when organic N-mineralization rates exceed 2%. Productivity and field-life potential decrease in the following order: Zuni, Mesa Verde, Bandelier, Chaco Halo. The Chaco Halo is very unproductive; e.g., 10 bushels per acre can be achieved within the Halo only from soils having the highest organic N concentration (third quartile) and which undergo the highest rate (3%) of N mineralization.     

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

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.     

Large freshwater plesiosaurian from the Cretaceous (Aptian) of Australia

Benson, R.B.J., Fitzgerald, E.M.G., Rich, T.H. & Vickers-Rich, P., 2013. Large freshwater plesiosaurian from the Cretaceous (Aptian) of Australia. Alcheringa 37, 1–6. ISSN 0311-5518

We report a large plesiosaurian tooth from the freshwater early–middle Aptian (Early Cretaceous) Eumeralla Formation of Victoria, Australia. This, combined with records of smaller plesiosaurian teeth with an alternative morphology, provides evidence for a multitaxic freshwater plesiosaurian assemblage. Dental and body size differences suggest ecological partitioning of sympatric freshwater plesiosaurians analogous to that in modern freshwater odontocete cetaceans. The evolutionarily plastic body plan of Plesiosauria may have facilitated niche differentiation and helped them to exclude ichthyosaurs from freshwater environments during the Mesozoic. However, confirmation of this hypothesis requires the discovery of more complete remains.

Roger B.J. Benson [roger.benson@earth.ox.ac.uk], Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK; Erich M.G. Fitzgerald [efitzgerald@museum.vic.gov.au], Thomas H. Rich [trich@museum.vic.gov.au], Museum Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia; Thomas H. Rich and Patricia Vickers-Rich [pat.rich@monash.edu], School of Geosciences, Monash University, Clayton, Victoria 3800, Australia. Received 30.10.2012; revised 27.1.2013; accepted 31.1.2013.     

Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest,Part 1: The Southern Colorado Plateau and Rio Grande Regions

Maize is the New World’s preeminent grain crop and it provided the economic basis for human culture in many regions within the Americas. To flourish, maize needs water, sunlight (heat), and nutrients (e.g., nitrogen). In this paper, climate and soil chemistry data are used to evaluate the potential for dryland (rain-on-field) agriculture in the semiarid southeastern Colorado Plateau and Rio Grande regions. Processes that impact maize agriculture such as nitrogen mineralization, infiltration of precipitation, bare soil evaporation, and transpiration are discussed and evaluated. Most of the study area, excepting high-elevation regions, receives sufficient solar radiation to grow maize. The salinities of subsurface soils in the central San Juan Basin are very high and their nitrogen concentrations are very low. In addition, soils of the central San Juan Basin are characterized by pH values that exceed 8.0, which limit the availability of both nitrogen and phosphorous. In general, the San Juan Basin, including Chaco Canyon, is the least promising part of the study area in terms of dryland farming. Calculations of field life, using values of organic nitrogen for the upper 50 cm of soil in the study area, indicate that most of the study area could not support a 10-bushel/acre crop of maize. The concepts, methods, and calculations used to quantify maize productivity in this study are applicable to maize cultivation in other environmental settings across the Americas.     

Coercive Harmony,Deep Capture and Environmental Justice in Puerto Rico

This article examines how a regional NGO and a local‐issue GRO in Puerto Rico have approached health and environmental concerns over water pollution from pharmaceutical production, and the consequences this has had for corporate–community–government relations. Through the analysis of historical material, public meetings and interviews, the processes through which micropolitical patterns have developed, and through which residents least conciliatory towards the drug companies are silenced, are discussed. The article questions whether persistent conflict between the corporate–government alliance and grassroots environmentalists is attributable to a ‘gap in understanding’ and suggests that the relationship is better understood through the complementary theories of ‘coercive harmony’ and ‘deep capture’. In conclusion it points out that researchers should be wary of assisting or supporting negotiations, and rather should focus on critically examining the dynamics of ‘stakeholder dialogue’ as a negotiation between relative equals.     

Broccoli and Desire

Abstract: Tracing the commodity chain of broccoli from Nashville, Tennessee supermarkets to Maya farmers in highland Guatemala, this paper examines relations of desire and political economic power. We argue that the global broccoli trade is shot through with desires—desires of Western consumers to eat healthy foods as well as desires for Maya farmers to get ahead economically. Such desires simultaneously subvert and sustain the hegemonic constellations that anchor crucial nodes in the international broccoli trade.     

Malebogo Mvimi: Past Environments and Plant Use in Holocene Southern Africa. A Study of Charcoal and Seed Remains from the Late Stone Age Sites of Toteng (Botswana), Leopard Cave and Geduld (Namibia)

African Archaeological Review -