Author: James Hunt (The University of Melbourne, CSIRO Agriculture and Food), Corinne Celestina, Arjun Pandey (The University of Melbourne), Yolanda Plowman (Birchip Cropping Group), Sam Trengove, Sarah Noack (Trengove Consulting), Rachael Whitworth, Barry Haskins (Ag Grow Agronomy + Research), Lindsay Bell and Rick Llewelyn (CSIRO Agriculture and Food) || Date: 5 Feb 2025

Take home messages

• The ‘right’ N fertiliser decision maximises profit, replaces N taken out in grain plus any N lost from the soil, and minimises chances of losing money in any given year.
• It is difficult to make the ‘right’ N decision every year, but ‘good’ decisions are relatively easy and are more likely to be ‘right’, particularly when reviewed over several years.
• There are many ways of making ‘good’ N decisions that suit different decision-making preferences – pick one that suits you and use it.
• Check that your ‘good’ decision-making system is ‘right’ in the short-term using grain protein, and in the long-term using a partial N balance.

Author: Lindsay Bell (CSIRO), Ismail Garba (CSIRO), Jeremy Whish (CSIRO), Jayne Gentry (QDAF), James Hunt (CSIRO / University of Melbourne)  | Date: 27 Feb 2025

Take home messages

• Getting your nitrogen (N) fertiliser strategy right is critical to maximising yield potential while avoiding risks of N losses, soil fertility decline and managing costs
• N budgets that target higher seasonal yield predictions, don’t require extra N year after year, as excess N is cycled into subsequent years and is not wasted.
• Rather than applying a crop-by-crop approach to N supply, take a multi-year perspective to maintain the soil N status to avoid continued soil fertility mining
• Setting an annual target N supply rather than tailoring this to each season can perform well in northern farming systems

Author: Peter Hayman (SARDI Climate Applications), Barry Mudge (Mudge Consulting) | Date: 06 Feb 2024

Take home messages

• When choosing a single target yield for N budgeting, a grower has one chance in 10 of selecting the right rainfall decile and only considers the year of application. . Concern about applying too much N contributes to conservative rates which have been identified as an important cause of the gap in actual and potential yield and profit.
• For growers and advisers who do want to consider a seasonally responsive approach to N management, we have developed the Fast Graphs for Slow Thinking spreadsheet (Figure 2), which uses the 40kg N/t wheat rule to consider the upside and downside by budgeting across all 10 deciles. We also encourage users to vary the rate of N carryover and see how this changes the risk and reward outcome.

Author: James Hunt (The University of Melbourne) | Date: 06 Feb 2024

Take home messages

• Nitrogen (N) fertiliser rate decisions based on soil test data and a formalised decision process are more profitable than fixed rates or decisions based on ‘gut feel’.
• This article goes back to basics on N budgeting and is designed to help young agronomists make better N fertiliser recommendations.
• The article simplifies a lot of complex topics and should just be a starting point for learning about N management in southern Australian farming systems.

Author: Yolanda Plowman, Kate Finger (Birchip Croppin Group), Jame Hunt, Arjun Pandey (University of Melbourne), Mark Farrell (CSIRO) | Date: 17 Jul 2024

Take home messages

• Some growers struggle with making informed nitrogen decisions but decision support systems or approaches like Yield Prophet® and N banks can help.
• Both strategies produce ideal outcomes, however Yield Prophet may be an ideal tool for ‘active’ managers, whereas N banks may be ideal for ‘passive’ managers.
• In a multi-year N management trial (2018-2023), the YP50% and NB125 strategies provided high gross margins, whilst mitigating environmental N loss through lower (but positive) partial N balances.

Author: Lindsay Bell (CSIRO), Ismail Garba (CSIRO), Heidi Horan (CSIRO), James Hunt (University of Melbourne) | Date: 30 Jul 2024

Take home messages

• Developing a robust nitrogen (N) fertiliser strategy is critical to maximising seasonal yield potential while avoiding long-term carbon decline and mitigating risks of N losses
• Tactical N budgeting in the face of uncertain seasonal outcomes is tricky and has high data demands to make helpful predictions of seasonal yield potential
• Longer-term strategic approaches can be simpler and have advantages of incurring costs following higher profit years, but have higher risks of N losses
• Take a multi-year perspective on nitrogen use efficiency and return on investment rather than just the year of application
• Strategic approaches like N banking can perform well in northern farming systems allowing yield potential to be maximised while avoiding environmental losses
• Setting the appropriate N target to balance the upside and downside risks is likely to be influenced by your risk attitude.