Mapping soil in Saskatchewan at the quarter-section level using image analysis

Abstract

Soil variability must be characterized if comprehensive, farm-scale management plans are to be developed in Saskatchewan. It has been suggested that image analysis of scanned black and white air photos could be used as a cost-effective method to characterize the variability of soils at the quarter-section scale. We examined the variability of soil groups and properties within a quarter-section mapped as a Oxbow association using field sampling and image analysis. The tonal variations within the scanned air photos were closely related to the organic carbon and inorganic carbon levels of the surface soil increment, and distinctive ranges of organic and inorganic carbon were in turn associated with the soil subgroups at the site. The image analysis resulted in a soil map of the quarter-section with a minimum cell resolution of 5m2. This technique holds considerable promise for extending the current series of 1:100 000 soil maps for the province to the quarter-section scale.