The science of Nitrogen (N) cycling in dairy systems can be poorly understood by dairy farmers and their agronomists, and consequently current farm practice is often to apply N at a set rate based on expected pasture growth. Amounts of N supplied to the pasture through mineralisation, and the variation in this supply over seasons, is not understood sufficiently to influence fertiliser decisions.

This project aims to gain a better understanding of the amount of N supplied through mineralisation to dairy pastures under dryland and irrigated conditions in one of dairy’s largest producing regions, South West Victoria. The findings will be utilised to develop a tool for farmers and advisers which will reliably estimate mineralised available N so that N fertiliser inputs can be adjusted accordingly. Further investigation of new N assessment technologies will also be undertaken. The outcomes of the project will provide opportunities to reduce costly N fertiliser inputs resulting in reduced loss to the environment and increased profit.