Iowa Soil Water Content – 15 Bar Maps (wilting point) [gSSURGO]
Author: Meyer Bohn
Water content, -15 bar, is the amount of soil water retained at a tension of -15 bars, expressed as a volumetric percentage of the whole soil material. Water retained at -15 bars is significant in the determination of soil water-retention difference, which is used as the initial estimation of available water capacity for some soils. Water retained at -15 bars is an estimation of the wilting point. Water content varies between soil types, depending on soil properties that affect retention of water. The most important properties are the content of organic matter, soil texture, bulk density, and soil structure.
Map Details
File Content
The zip file contains the base GeoTIFF soil property rasters, OVR pyramid files (reduced resolution for faster display), AUX auxiliary files (Raster color map, statistics, histogram, table, pointer to pyramid file, coordinate system, transformation, projection information), TFW world files (GeoTIFF coordinate system information), and a LYRX file (stored symbology for viewing in ArcGIS Pro v 2.2 or later) and a LYR file (stored symbology for viewing in ArcGIS for Desktop), and associated metadata in a RTF file.
Metadata – Sources – Limitations
Produced by: Meyer Bohn, Joshua McDanel, and Bradley Miller January (2019)
Created with the gSSURGO mapping toolset for ArcGIS for Desktop 10.6. Available for download at:
https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053628
Raster Format: 10-m resolution GeoTIFF, 32-bit floating point
Projection: NAD83 UTM Zone 15N
Extent – West: -96.801571 East: -90.007463 North: 43.644364 South: 40.302683
Soil Survey Staff. 2018. Natural Resources Conservation Service. United States Department of Agriculture. Gridded Soil Survey Geographic (gSSURGO) Database for Iowa. Accessed 27 Oct 2018.
Use limitations: See “Sources of Apparent Error on Existing Soil Maps”. Soil Survey Staff. 2018. Soil Survey Manual – Ch. 4: Soil Mapping Concepts. Natural Resources Conservation Service. United States Department of Agriculture. Available at:
https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_054254#quality
Scale Range: Not intended for use at scales larger than an order 2 Survey (1:12,000 to 1:31,680).
Available Depths
- 0 – 5 cm • 5 – 20 cm
- 0 – 20 cm • 20 – 50 cm
- 0 – 30 cm • 50 – 100 cm
- 0 – 100 cm • 100 – 150 cm
- 0 – 150 cm • 150 – 200 cm
- 0 – 200 cm