Developing a decision support tool for optimising organo-mineral fertilisation strategies and improving nitrogen use efficiency

Johannes Biala1, Daniele De Rosa1, David Rowlings1, Peter Grace1

1Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia,,


Farmers are under pressure to operate more efficiently and reduce negative environmental impacts while maintaining or increasing production. Accurate accounting for nutrients supplied with organic soil amendments and appropriate reduction of mineral fertiliser inputs provides an easy way of achieving these goals. This paper outlines what is necessary to develop a decision support tool for optimising fertilisation strategies that utilise both organic and synthetic nutrient sources and improve nitrogen use efficiency. Novel aspects of the proposed calculator are that (i) it integrates organic and synthetic N sources, (ii) it caters for repeat applications and accounts for long-term nutrient release, (iii) it incorporates a paddock-scale nutrient budget, and (iv) it has scope for future expansion to include changes in soil properties brought about by the use of organic soil amendments.