Validation of precision agriculture soil mapping services under practical conditions

This study confirmed that soil mapping services can produce good quality soil maps showing within-field spatial variation of clay and soil organic matter contents. The results were better when there was a wider range of variation of the parameter in the field. In those cases, correlation coefficients in regression analyses between soil analysis laboratory reference data and soil mapping service data were high (R-2 between 0.7 to 0.8). A proximal sensor system based on gamma radiation and on EC plus NIRS provided the best soil maps on spatial variation of clay and soil organic matter content. The remote sensing sensor system applying hyperspectral imaging scored a bit less than the two proximal sensor systems mentioned, yet still useful in precision farming.