Pre-Columbian Rock Mulching as a Strategy for Modern Agave Cultivation in Arid Marginal Lands

Abstract

Cultivation of C 3 and C 4 crops in semi-arid regions will be severely constrained as global temperatures rise. Consequently, alternative crops need to be sought out that adapt well to heat and drought and are productive despite limited access to water. Traits, such as crassulacean acid metabolism (CAM), enable economically important species such as those in the Agave genus adapt to drought and high temperatures. The succulence and high efficiency of agaves, which enables them to produce biomass with little water, underscores their feasibility as an alternative crop for semi-arid regions, such as the Sonoran Desert in the southwestern U.S. In this paper, we offer a review of the suitability for cultivation of agaves via dryland farming, particularly by rock mulching techniques used by pre-Columbian, Sonoran Desert farmers. This analysis dovetails with information also provided on the biological traits of Agave and its historical and present utilization. Pre-Columbian, Hohokam dryland farmers used rock mulching in the form of rock piles to cultivate agaves. Rock piles acted as a type of mulch to harvest rainfall and to retain soil moisture, which allowed the Hohokam to intensively cultivate agaves during multi-year droughts. Remains of Hohokam rock mulching for agave production can be found at archaeological sites in central Arizona, which provides evidence of the utility of dryland farming and ancient agricultural innovation to reconcile water scarcity in the region. Moreover, the use of rock piles likely bolstered Agave productivity in marginal lands. Although little is known of historic rock mulching to cultivate agaves and its biological implications on plant productivity we suggest its application as a dryland farming model could be a sustainable strategy in the U.S. Southwest.

Ecological-niche modeling reveals current opportunities for Agave dryland farming in Sonora, Mexico and Arizona, USA

“…The economic potential of Agave as a drought-tolerant crop for arid regions has been extensively characterized [10-12, 26, 74]. However, despite the substantial research on the impacts of climate change on Agave, little research has been conducted on Agave dryland-farming cultivation in the borderlands of Arizona and Sonora [6]. Current patterns of climate changes pose challenges to the Agave agricultural industry in Sonora.…”

“…In the Sonoran Desert, beginning in pre-Columbian times, Agave was cultivated and used for centuries as an unabated source of food, drink, medicine, and fiber [2][3][4][5]. Desert farmers, such as the Hohokam, innovated drylandfarming techniques to cultivate Agave using rainfall runoff and rock mulching, also known as Hohokam rock piles [2,4,[6][7][8][9]. Hohokam dryland farming made the extensive cultivation of Agave possible as a staple crop in the Sonoran Desert [2,4].…”

“…Hohokam dryland farming made the extensive cultivation of Agave possible as a staple crop in the Sonoran Desert [2,4]. Principles of Agave dryland farming, which enabled the Hohokam to successfully cultivate Agave, can be applied to the modern Agave agricultural industry, which is currently impacted by rising global temperatures and droughts [6,[10][11][12].…”

Lessons from the history of Agave: ecological and cultural context for valuation of CAM

“…Large-scale production of Agave species for human consumption is evident in North America even during pre-Columbian times (e.g. Ortiz-Cano et al , 2020 ). Researchers such as Gentry (1982 , 2004 ), Valenzuela-Zapata and Nabhan (2004) , Vargas-Ponce et al (2007 , 2009 ) and others have documented the many landraces of Agave and their relationship to cultural history in the Americas.…”

Life Without Water

“…Many of earth’s biodiversity hotspots coincide with arid or semiarid regions, including Mesoamerica, the Succulent Karoo in South Africa, and the mediterranean‐climate regions of the world (Myers et al, 2000; Grace, 2019). Arid‐adapted plants have important ethnobotanical value in western and indigenous cultures as well (Grace et al, 2015; Hodgson et al, 2018; Ortiz‐Cano et al, 2020). With climate change projected to increase the severity and frequency of drought events—particularly in regions already experiencing water limitation (Grace, 2019)—the biodiversity of arid habitats represents an important conservation focus (Scherson et al, 2020).…”