Calibrated SoilOptix ® estimates of soil pH and exchangeable cations in three agricultural fields in western Canada - implications for managing spatially variable soil acidity.

Spatial variability in soil pH is a major contributor to within-field variations in soil fertility and crop productivity. An improved understanding of the spatial variability of soil pH within agricultural fields is required to determine liming requirements for precision farming. This study with the use of proximal sensors, firstly assessed the spatial pattern of soil pH and how it can be used to determine site-specific, spatially variable lime requirements.