Meteoric Beryllium-10 as a tracer of cumulative erosion due to post-settlement land use in west-central Minnesota, USA

Authors: JELINSKI, NICOLAS - University Of Minnesota; WILLENBRING, JANE - University Of Pennsylvania; SCHUMACHER, THOMAS - Retired Non ARS Employee; LI, SHENG - Agriculture And Agri-Food Canada; LOBB, DAVID - University Of Manitoba; Schneider, Sharon; YOO, KYUNGSOO - University Of Minnesota

Submitted to: Journal of Geophysical Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2019
Publication Date: 2/20/2019
Citation: Jelinski, N.A., Willenbring, J.K., Schumacher, T.E., Li, S., Lobb, D.A., Papiernik, S.K., Yoo, K. 2019. Meteoric Beryllium-10 as a tracer of cumulative erosion due to post-settlement land use in west-Central Minnesota, USA. Journal of Geophysical Research: Earth Surface. 124(874–901). https://doi.org/10.1029/2018JF004720.
DOI: https://doi.org/10.1029/2018JF004720

Interpretive Summary: Understanding landscape change in regions dominated by agricultural land-use is critical to predicting the future sustainability of soils for agronomic and environmental benefits. In this study, we used meteoric Beryllium-10 (10Be) to quantify pre- and post-settlement erosion rates across a hillslope in an intensively cultivated landscape. This work is novel because few studies have used 10Be to determine spatially-explicit long-term erosion rates from upland soils in agricultural landscapes. Results suggest that erosion rates were about 100 times higher after settlement than before: pre-settlement erosion rates on the cultivated transect averaged 0.38 ± 0.16 Mg ha-1 y-1, whereas total post-settlement erosion rates average 31 ± 20 Mg ha-1 y-1. Cultivation and cropping for >100 years have effectively removed 26 cm (10 inches) of soil from upper hillslope positions. The rates derived from 10Be are comparable to those derived using another isotopic tracer (137Cs), and with soil erosion determined using the WATEM model. Other properties of the soils at this site (soil carbon, etc.) support these erosion estimates. We conclude that applying 10Be to study long-term erosion in upland agricultural soils holds strong potential, and can result in novel insights into the influence of land-use change on erosion rates.

Technical Abstract: Soil sustainability in agricultural landscapes is highly dependent upon the pattern and intensity of wind, water, and tillage erosion, and is closely related to carbon cycling, nutrient status, and crop productivity. Radioisotope tracers such as 137Cs have long been used to study soil erosion due to land-use on timescales from days to decades. In contrast, meteoric Beryllium-10 (10Be) has been under-utilized in anthropogenic landscapes as a tracer of erosion and soil truncation despite its ability to provide insights into erosion and landscape change on timescales of centuries to millennia. In this study, we present meteoric 10Be data from paired uncultivated and cultivated sites in west-central Minnesota, USA, and determine the relationship of 10Be to soil organic carbon (SOC), soil inorganic carbon (SIC) and 137Cs data across land-uses. Meteoric 10Be concentrations were highly correlated to SIC but not 137Cs activities. We apply conversion models to 10Be data in order to estimate pre- and post-European settlement erosion rates across the cultivated transect. Results suggest that pre-settlement erosion rates on the cultivated transect averaged 0.38 ± 0.16 Mg ha-1 y-1, whereas total post-settlement erosion rates average 31 ± 20 Mg ha-1 y-1. The rates derived from 10Be are comparable to those derived from 137Cs and previously simulated water and tillage erosion rates based on topography driven models (WATEM). Meteoric Beryllium-10 is an important tool for anthropogenic systems, which, when used in conjunction with shorter-lived isotopes, models, and geospatial data, can provide novel insights into the evolution and long-term sustainability of agricultural landscapes.