Functional soil mapping for site-specific soil moisture and crop yield management

To advance site-specific management, detailed functional (application-orientated) soil maps are desirable. This study presents an example of a functional soil map for the management of crop yields and soil moisture in an agricultural landscape located in central Pennsylvania, USA. A high-intensity soil map was prepared using electromagnetic induction (EMI), terrain attribute, and soil core data. Two soil properties, A horizon texture and depth to clay layer were found to be significantly correlated (p < 0.05) with soil moisture and crop yields (corn and soybean). A functional soil map was generated by overlaying these two properties on the high-intensity soil map. Spatial and temporal variations in soil moisture and crop yield within different functional map units were statistically compared with those within different map units on the second-order and the high-intensity soil maps. While soil moisture and crop yield did not show obvious difference among map units of the second-order soil map, clear differences were observed among the functional soil map units developed in this study. This study demonstrates that the accuracy and utility of second-order soil maps for site-specific management can be improved using EMI and functional soil mapping approaches.

► A functional soil map was generated from EMI, soil sampling and terrain analysis.
► Soil moisture was better captured in the functional soil map than general soil maps.
► Crop yield was better captured in the functional soil map than general soil maps.
► This study proposes an improved approach for accurate and functional soil mapping.