The soil biological nitrogen cycle is mediated by physiologically diverse microbial communities that have evolved in accordance with heterogeneous soil microhabitats. It is likely that the distribution of microbial taxa and functions associated with the transformation of the many forms of soil nitrogen is characteristic of the diverse microhabitats of Australian soils. Assisted by various genetic sequencing technologies and databases such as BASE (Biome of Australian Soil Environments; Bissett et al 2016) and other industry supported databases, over 1000 samples are utilised to describe the mainly bacterial and archaeal taxa that are typically associated with nitrification in the major climatic zones of Australia, incorporating Christmas and King Island and northern Antarctica. It compares the impacts of disturbance associated with agriculture and non-agricultural across a range of soil orders on the distribution and abundance of prominent autotrophic taxa implicated in ammonium and nitrite oxidation. It also presents an examination of the distribution and abundance of genes typically associated with the N cycle such as amoA, amoB and nifH and the key physical and chemical correlates that explain geographical occurrence patterns. The implications of describing the abundance and distribution of taxa and N cycle genes for measuring, monitoring and managing soils in food and fibre production systems in Australia are explored.