This project investigates Pre-Columbian agricultural fields which relied on runoff irrigation technologies unique to the ancient southwestern United States. Understanding how runoff irrigation and water management influenced vegetative productivity is critical to understanding the widespread occurrence of this technology in certain parts of the region and has implications for understanding how humans have shaped contemporary ecosystems. In addition to contributing to a scientific understanding of the function and persistence of runoff irrigation technology, this research addresses questions about the benefits for the application of traditional farming practices in the modern day. Because these features developed in a water limited environments, and are known only through archaeological research, facts regarding their character and function contribute information important to agriculture in present day drylands and have implications for water diversion and conservation. Finally, the project will contribute to undergraduate student training in field and laboratory techniques in he fields of archaeology and environmental science.
The relative productivity of ancient runoff irrigated fields will be measured at scales ranging from centuries to single years in northern New Mexico. Particular focus will be given to fields that were mulched with pebbles and cobbles. Fields of this type are particularly abundant, and the technology was apparently well developed in this area. Soil and vegetation characteristics have been documented for other dryland field types in the Southwest, but few comparable studies have been conducted on rock-mulched fields. The study will rectify this knowledge gap and generate data that will allow comparison across the Southwest. Year-to-year changes in the width of growth rings for trees established on fields will be measured to determine how water conserving features may buffer trees from periodic droughts. Relative levels of organic material in soils, which are derived from plant matter, track how water conserving features alter plant productivity over the last few centuries. Together, soil chemistry and tree-rings will help answer questions about how ancient agricultural investments continue to effect contemporary ecosystem productivity, and the role this infrastructure played in supporting the large communities of northern New Mexico from 1300 A.D. until Spanish contact in the 1600s.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
