Biogeochemical studies of a Native American runoff agroecosystem

Abstract

Research on soil fertility is presented in the context of runoff agriculture, a venerable farming system that has been used for millennia in arid to semiarid regions, where water is a major limiting resource for crop production. The agroecology of runoff farming was studied with the Zuni to evaluate nutrient and hydrologic processes, management, maize productivity, and soil quality in some of the oldest recognized fields in the United States. This ancient Southwest agriculture has functioned without conventional irrigation or fertilization by tapping into biogeochemical processes in natural watersheds connected to fields. Carefully placed fields are managed on alluvial fans and other valley margin landforms to intercept runoff and associated sediment and organic debris transported from adjoining forested uplands. We report on research to evaluate and link nitrogen and phosphorus, two key nutrients for crop production, in watershed, soil, and crop components of this agroecosystem. Nutrient data have been collected by observational and experimental methods for each component and the transport of nutrients from watershed to field to maize. The condition of Zuni agricultural soils suggests that their knowledge and management of soils contributed to effective conservation. This study and others indicate the need for further long‐term monitoring and experimental research on watersheds, runoff processes, field soils, and crops across a range of arid to semiarid ecosystems. © 2007 Wiley Periodicals, Inc.

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

“…In Part 1 of this study, the seminal studies of Jon Sandor and his colleagues who dealt with the transport and transformation of N-containing organic matter in the Zuni Reservation were introduced (Homburg et al 2005;Norton et al 2003;Norton et al 2007a, b;Sandor et al 2007). As part of his thesis, Homburg (2000) measured a variety of chemical and physical parameters in 29 soil profiles from three Zuni field areas (Nutria, Pescado, and Bear Canyon), including pH (1:1 solution), organic C, total N, and available P (Olsen-P extraction method).…”

The role of geoarchaeology in extending our perspective

“…Any measures to enhance resilience and promote adaptation must take account of local contexts and recognize that imported developmental models may be inappropriate; indigenous livelihood strategies have often emerged from centuries or even millennia of linked environmental and social change. ' Sandor et al (2007) also discussed the implications of their geoarchaeological study for our current situation. They looked at runoff agriculture, which has for millennia allowed crops to be grown successfully in arid lands, as it not only increases water supply to the crops but also results in enriched soils owing to the influx of nutrient-rich organic matter and sediments.…”

“…Hill 2007a, b;Rech et al 2007;, from only hundreds of years old up to the present (e.g. Guttmann et al 2006;Sandor et al 2007), or any age range between them. Geoarchaeologists are also aware of the importance of information from sources beyond archaeological sites: regional geomorphology, non-cultural stratigraphic sequences, and so on (e.g.…”

“…These studies can reveal additions to soils (e.g. Bintliff et al 2006;Guttmann et al 2006Guttmann et al , 2008Simpson et al 2006), or other techniques such as terracing (Krahtopoulou & Frederick 2008) or runoff irrigation (Sandor et al 2007), which create or improve arable land, or otherwise allowed communities to manage risk (Zaro & Alvarez 2005). Human land-use practices can have unintended consequences, however, which can be either positive or negative.…”

Selected highlights in American soil science history from the 1980s to the mid-2010s

“…Soil science techniques have been used to address a variety of pedoarchaeological research topics. Examples of some of these other applications include: (1) pH analysis to assess bone preservation potential (Linse, 1992); (2) identification of ancient fields and soil productivity evaluations (Dart, 1986;Homburg and Sandor, 2011;Huckleberry, 1992;Sandor, 1995;Sandor andHomburg, 2011, 2015;Sandor et al, 2007); (3) use of soil P analysis to identify intra-site activity areas on ancient occupation surfaces and to interpret soil stratigraphy (Homburg, 1988); (4) soil micromorphology analysis of archaeological deposits and ancient agricultural fields (Courty et al, 1989;Purdue et al, 2010;Fig. 3); (5) analysis of cores for the purpose of landscape reconstruction (Ciolek-Torrello et al, 2013;Homburg et al, 2014a); (6) use of soil survey maps to predict the potential for buried archaeological sites and the agricultural productivity of ancient agricultural systems (Green et al, 2012;Heilen et al, 2013;Homburg et al, 2014b); and (7) analysis of strength of adobe material used in ancient single-and multi-story adobe architecture, based on soil properties such as bulk density, carbonate content, and penetration resistance (Howell and Homburg, 2013).…”