Soil varies from location to location as a result of complex combinations of soil forming factors and processes operating at different scales and intensities. The scale-dependent variability in soil properties causes challenges for the characterization and mapping of soils. With the advent of technologies, proximal sensors such as gamma radiometrics can characterize soil spatial variability and the digital mapping of soil properties. In this study we aim to characterize scale-dependent variability of proximal gamma radiometrics and its complex relationship with soil properties at different scales using wavelet transform and wavelet coherency. We measured gamma radio metrics (gamma-ray potassium (K-40), uranium (U-238), thorium (Th-232) and Total Count (gamma-TC)) using a hand-held device in the field every 25 m along a 3.0 km transect. At each point we measured elevation (m) and land use and collected soil samples to determine key soil properties (electrical conductivity EC1:5, pH (CaCl2), soil organic carbon (SOC), cation exchange capacity (CEC), exchangeable potassium (exch. K), and Colwell P). Wavelet spectra identified significant (P < 0.05) variations at different scales and locations for both gamma-ray and soil properties. There were significant localized variations with changes in elevation and land use also important. In most cases a 'global' Pearson correlation between the gamma-ray and soil properties was not significant. In contrast, wavelet coherency provided a more powerful scale-and location-specific relationship between gamma-ray, elevation and land use with selected soil properties. For example, a strong correlation (18% of the area was significant) was detected between land use and soil EC1:5 at all scales (800 m) there was significant positive correlations between gamma-TC and SOC (36% by area). At medium scales (similar to 400 m) there was significant and positive correlations between K-40 and CEC (23% by area), but only along the first half of the transect which was underlain with Bushy Creek Granodiorite. These findings provide an improved understanding of the spatial variability of gamma-ray-soil relationships. The approach used shows the scope and significant potential to use wavelet analysis of gamma-soil property relationships that are scale-specific and would be useful for digital soil mapping. Moreover, scale-specific spatial information of soil properties aids understanding of soil formation processes and it illustrates an approach to improve future soil sampling strategies. (C) 2017 Elsevier B.V. All rights reserved.