Cosmogenic in situ 14C-10Be reveals abrupt Late Holocene soil loss in the Andean Altiplano

Soil sustainability is reflected in a long-term balance between soil production and erosion for a given climate and geology. Here we evaluate soil sustainability in the Andean Altiplano where accelerated erosion has been linked to wetter climate from 4.5 ka and the rise of Neolithic agropastoralism in the millennium that followed. We measure in situ cosmogenic C-14 directly on cultivated hilltops to quantify late Holocene soil loss, which we compare with background soil production rates determined from cosmogenic Al-26 and Be-10. Our Monte Carlo-based inversion method identifies two scenarios to account for our data: an increase in erosion rate by 1-2 orders of magnitude between similar to 2.6 and 1.1 ka, or a discrete event stripping similar to 1-2 m of soil between similar to 1.9 and 1.1 ka. Coupled environmental and cultural factors in the Late Holocene signaled the onset of the pervasive human imprint in the Andean Altiplano seen today.

Automated summary

Soil sustainability in the Andean Altiplano has been evaluated by measuring soil erosion and production rates during the late Holocene, revealing a significant increase in erosion linked to environmental changes and the development of Neolithic agropastoralism. The study used in situ cosmogenic C-14 measurements on cultivated hilltops to quantify soil loss and compared it with background soil production rates to identify two scenarios explaining the data. This research highlights the impact of environmental and cultural factors during the late Holocene in the Andean Altiplano.