Pedoarchaeology in the pre-Hispanic terraces of Cusco

Isminio D.A.L.; Schaefer C.E.G.R.; Do Amaral E.F.; Isminio P.L.; Senra E.O. · Revista Brasileira de Ciencia do Solo (2026) · DOI: 10.36783/18069657rbcs20250032

Resumen

The High Andean systems of agricultural terraces are a Pre-Hispanic cultivation technique that allowed the development of one of the most extraordinary civilizations on steep slopes and dry land by the intensive conditioning and management of constructed soils. Despite recent advances, little is known about long-term changes in these constructed soils, especially in the context of high-mountain ecosystems. This study aimed to investigate the morphological, physical, chemical, and mineralogical properties of 13 soil profiles from highland soils in the upper parts of Cuzco province and to establish a chronology based on C14 dating. Nine soil profiles with clear anthropogenic influence were compared with four profiles that showed no marked anthropogenic influence. The anthropogenic horizons varied in thickness from 0.20 to 1.40 m, and many contained buried horizons enriched in organic matter. The high values of P found in anthropogenic soils highlight the long-term soil management practices with a consistent cumulative improvement, especially in cases of extremely high values in P (Mehlich-1) and total P2O5 (total), with radiocarbon age in some cases of 4110 +/-30 BP, and therefore from the Pre-Ceramic period (Pre-Inca). Clay mineralogy is very similar in all soils (constructed or natural) dominated by chlorite, illite, kaolinite, and quartz. Soils of the sub-humid region in the higher parts of the study area show less pedogenetic evolution. Despite the low precipitation and rejuvenation, a higher degree of pedogenesis was observed in the highland semi-arid environment, with well-crystalline forms of Fe oxides, such as hematite.

Instituciones: Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas