Comparison of a digital soil map and conventional soil map for management of topsoil exchangeable sodium percentage

The soil in the sugarcane growing area of far north Queensland is often sodic (exchangeable sodium percentage—ESP > 6%). Gypsum therefore needs to be applied to reduce potential for land degradation. To accurately map ESP, a digital soil map (DSM) approach can be used. In this paper, we compare and contrast various aspects of DSM for mapping topsoil (0–0.3 m) ESP, including a suitable model (i.e. linear mixed model (LMM), Cubist and...