Cropland management impacts on soil organic carbon stock changes in US croplands from 1990 to 2015
Data files
Jul 25, 2023 version files 3.64 MB
-
Counterfactual_Scenario_geospatial_data.zip
-
README.md
Abstract
This geospatial dataset represents soil organic carbon stock changes estimated from a counterfactual analysis of climate-smart soil management practices that were adopted in U.S. croplands between 1990 and 2015. The counterfactual scenarios are relative to historical cropland management implemented in the U.S. for the temporal domain of this study. These data provide a large-scale overview of the carbon stock changes in US cropland agricultural soils associated with conservation tillage, manure amendments, cover crops terminated with cultivation, cover crop terminated with herbicide, hay and pasture in rotation with annual crops, set-aside/Conservation Reserve Program lands. Data were generated using the DayCent ecosystem model driven by cropping histories in the USDA National Resources Inventory (NRI) and associated agricultural management data. The average annual stock change was calculated for each management practice to determine the impact. Average rates of annual stock changes on a per-hectare basis (averaged from 1990 to 2015) are presented as a gridded dataset. Data are in a GeoTIFF format on a 5 km grid.
Methods
Six grids, one for each counterfactual scenario, are provided as GeoTIFF raster data files. Each GeoTIFF file has 627 rows x 967 columns with a 5 km resolution. Each grid cell value represents the change in soil carbon due to the management practice and is in units of metric tons of carbon per hectare per year. The values are averages from 1990 to 2015, and a positive value represents an increase in soil C given the management practice.
Point-level scenario stock differences are interpolated to a gridded map product. They were created using an interpolation process with an inverse distance weighting spatial method that determines each grid cell value using a linear-weighted combination of sample points within a threshold distance of 20 km. NRI survey locations closer to the cell centroid are given more weight in calculating the SOC stock change than points further from the centroid. We required a minimum of 5 NRI survey locations within the 20 km threshold to calculate a grid cell value; otherwise, the grid cell is set to a fill value of -9999. In addition, a mask is used to calculate values in cells where cropland should exist based on the National Land Cover Dataset (NLCD). Rasters are projected in a spatial reference of Albers Equal Area Conic in units of meters, with a central meridian at -96 degrees longitude and standard parallels at 29.5 and 45.5 degrees latitude. The North American 1983 Datum is used.
- Upper-Left coordinate: 3312635, -2493045 m
- Bottom-Right coordinate: 2341955, 177635 m
GeoTIFF Raster File Names:
1. Each GeoTIFF layer is comprised of 4 different files (.tif, .tfw, .tif.aux.xml, .tif.ovr)
Counterfactual Scenario GeoTIFF File Figure (see attached JPG file).
Figure: Scenario: GeoTIFF File:
A. Conservation tillage ConsTill_dSOC_MTCpha.tif
B. Manure additions ManureAmend_dSOC_MTCphs.tif
C. Cover crops terminated with herbicide CovCrop_Herb_dSOC_MTCpha.tif
D. Cover crops terminated with tillage CovCrop_Cult_dSOC_MTCpha.tif
E. Hay/pasture in rotation with crops HayPast_dSOC_MTCpha.tif
F. Set-aside/CRP land use CRP_dSOC_MTCpha.tif
Usage notes
Any program or image processing software that is compatible with GeoTIFF formats (e.g., ArcGIS).