Geographic Soils Information


Soil Spatial Variability in the Field

  • Small-Scale Soil Variability

       Central Wisconsin Farm





  • Medium-Scale Soil Variability

Drainage Catina





  • Large-Scale Soil Variability




Techniques & Tools For Mapping Soils

  • Soil Description -
    • The heart of soil mapping is still the soil pit
    • Once dug, detailed observations are recorded



              35cm Active Soil Layer. Ice Wedge at 55cm.








  • Delineating Soil Boundaries




(a) Hand-powered soil auger

(b) Truck-mounted hydraulic soil probe

(c) Air photo with soil boundary outline









(a) Regularly spaced grid pattern of sample locations is labor intensive.

(b) More efficient is apply knowledge where scientist expects soil properties to change.





Modern Technology For Soil Investigations

  • Ground-Penetrating Radar






USDA - Natural Resources Conservation Service
Ground Penetrating Radar Program








  • Electromagnetic Induction


Map of a 7 ha field showing the apparent electrical
conductivity (EC
a) in the surface 90 cm of soil as measured
by an electromagnetic induction [EM] meter.






  • Global Positioning Systems




Remote Sensing Tools For Soils Investigations

  • Air Photos
    • Air Photos As Base Maps

  Willamette valley of western Oregon







Satellite imagery

1973 Landsat satellite images showing a portion of an irrigation project in western Marja, Afghanistan.