As a result of reaching this audience, it was expected that the cumulative effect of the cascading extension strategy and input of BFDC Interrogator critical nutrient concentrations in commercial soil analysis interpretation software would indirectly and directly influence the crop nutrient management decisions of up to 5000 Australian grain farmers in the year after the commencement of training activities. Exit survey results, conducted as part of the BFDC train-the-trainer workshops, were aggregated across all Level 1 workshops. These survey results showed that the most significant benefit of the training was the usefulness of the BFDC Interrogator training manual and the additional teaching aids supplied. The importance and significance to the industry of the collation of data through BFDC was also highlighted as a benefit. Reflecting industry knowledge gaps (e.g. crop x nutrient x geographic region interactions), the lowest ranking survey results focused on the ability of the BFDC National Database to provide usable critical soil test criteria for several situations. Yet despite this reported shortcoming, participants recognised the significance of the structure, tools, skills, and knowledge gained through the training workshop and the importance of the established critical levels. While face-to-face training enables robust discussion, the 'time-poor' nature of roles for agricultural professionals appeared to limit the uptake of training opportunities. Therefore, training materials are being developed into an online course focused particularly on university requirements and the development of agricultural professionals.Scientists readily suggest that research and development is not complete until findings and conclusions are reported in the peer-reviewed literature. The authors suggest that industry-specific relevant research and development is actually not complete until the key outputs are extended to primary stakeholder groups. In the case of 'Making Better Fertiliser Decisions for Cropping Systems in Australia' (BFDC), this meant training key members of the grains and fertiliser industries, where nitrogen, phosphorus, potassium, and sulfur recommendations are derived from soil tests and provided to farmers. The BFDC project applied a two-part cascading approach to extension and training to reach the grains and fertiliser industries. The train-the-trainer program (Level 1) was undertaken and targeted at influential and experience persons such as technical leaders and those who influenced crop-nutrition decision support systems (DSS) within interested organisations. Level 2 activities targeted individuals within organisations who had direct discussion with farmers about soil testing, and their training was facilitated by a Level 1 trained colleague. Development of extension plans, training course structure, and training resources was conducted in parallel with the development of the BFDC National Database and BFDC Interrogator from the commencement of the project. In so doing, it was agreed that controlled access to the information should be established to maintain a consistent standard of use and to provide a platform for gathering feedback to guide future developments (e. g. of the BFDC Interrogator or prioritising future experimental investment). The BFDC extension approach targeted 100 individuals from the Level 1 audience and 30 individuals from the Level 2 audience through seven train-the-trainer level workshops conducted across Australia.