Increasing Profit from N, P and K Fertiliser Inputs into the Evolving Cropping Sequences in the Western Region

⁠⁠⁠Systems for prediction of fertilizer requirements take account of the complex biophysical and economic context within which our crops are grown. They involve an understanding of the current nutritional status as impacted by soil type and past history of application, crop specific response functions, yield expectations including likely climatic constraints as well as input costs and prices and the potential for residual value of applied fertiliser. Much has changed in recent times with cropping systems and sequences in the Western Region meaning that the context surrounding input information for fertilizer decisions has changed. We need to continuously update our understanding of the factors that connect fertilizer use to crop profitability. This is particularly relevant at times like the present when systems and crop sequences are rapidly evolving and input costs and prices are volatile.

This GRDC investment is to:
Nitrogen
* By 30 June 2022, complete a program of research and generate new knowledge and understanding of N within the farming system with a focus on:
* Direct measurement of the quantities and fate (including plant uptake) of N immobilised and mineralised from the soil organic pool, different types of stubble (species, amount, management, fallow), residual N fertiliser, legume-derived pools (including different species).
* Assessment of changing N mineralisation rates due to increasing summer/autumn rain in the Western Region and the impact on crop N requirements.
* The economics of N decision making in Western Region farming systems.
* By June 30 2022, update and make available the Select Your Nitrogen (SYN) model incorporating new knowledge from output 1.

Phosphorus
* By June 30 2022, complete a series of experiments and generate new knowledge to determine the impact, including economics, of repeatedly applying low rates of P at crop establish. The research should focus on wheat, canola and lupins.
* By June 30 2022, complete a series of experiments and generate new knowledge to understand P availability and measurement thereof within the soil profile.
* The extent, impact and ways to correct P deficiency in sub-soils.

Potassium
* By 30 June 2018 complete a technical and economic review and present GRDC with a report on the suitability of soil test methods to predict K responsiveness for the key soils in key environments across the Western Region.
* By 30 June 2022, complete a series of experiments and generate new knowledge and understanding of K in the dominant soil types in Western Region. The research will focus on:
* Understand K transformations and the fate of soil and fertiliser K.
* Physiology of plant uptake of K and K use efficiency in wheat, canola and barley.
* K movement into and through soils including the extent and depth of K leaching.
* The extent, impact and ways to correct K deficiency in sub-soils.
* The economics of K application in Western Region farming systems.

Additional Outputs
* By June 30 2022, at least one (1) post-doc researcher and two (2) PhD students have completed projects.
* Research topics can be N, P, K or trace elements.
* Annually, for the life of the project, upload all field trial results to the Better Fertilisers Decisions Cropping database.
* By June 30 2022, at least seven peer reviewed journal articles published communicating the results of the research in outputs 1 to 7.
* Annually, for the life of the project, deliver extension and training to increase the skill of at least 600 growers, advisers and industry professionals. As a minimum this will include;
* Presentations at field days and Updates workshops in Perth and regional areas.
* At least three workshops per annum delivering technical knowledge to advisers.
* At least five workshops per annum extending research outputs to growers.
* By March 2018, and each subsequent year, an Annual Progress Report detailing the key findings of the project for the reporting period.
* By June 2022, a Final Technical Report amalgamating the key findings, new knowledge and conclusions of the project to provide an overall interpretation of the work.