Data from: Soil organic carbon and isotope composition response to topography and erosion in Iowa

The dataset includes topographic information, soil properties, and 137Cs levels collected from a 15 ha cropland under soybean/maize (C3/C4) rotation in June 2002. The cropland is located in the central-western part of the Walnut Creek watershed, Story County, Iowa. 128 sampling locations were collected and three soil samples were obtained using a 3.2 cm-diameter push probe from the 0 to 30 cm soil layer within a 1 m × 1 m quadrat at each sampling location. Deeper soil samples were collected from 30 to 50 cm layers in locations where sediment deposition was observed. The three samples from each sampling location were mixed and analyzed to determine soil properties, SOC content and its carbon (C) isotope composition (C12 to C13 ratio), and 137Cs levels. For landscape topography of each sampling location, topographic metrics were derived from a digital elevation mode using LiDAR (Light Detection and Ranging) data. These data are useful in investigating the fate of eroded SOC in croplands and its responses to landscape topography.

For more information about this dataset contact: Gregory W. McCarty: Greg.McCarty@ars.usda.gov Xia Li: xiali626@umd.edu

• Resource Title: Topographic metrics of the study site.

  File Name: Topograhic_metrics.csv

  Resource Description: The file includes fourteen topographic metrics. All of the selected metrics were reported to affect soil erosion and deposition in the literature.




• Resource Title: Soil properties of the study site.

  File Name: Soil_properties.csv

  Resource Description: Soil texture, soil redistribution, soil organic carbon and its isotopes were included. Soil redistribution were calculated using the Mass Balance model II (MBMII) by Walling et al. (2011)




• Resource Title: Data Dictionary.

  File Name: Data_Dictionary.csv

  Resource Description: Data definitions and units for the variables in the soil property and topographic metric data files