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  • Billie White

N&P budgets for sugarcane

N&P budgets were introduced in late 2019 but were not compulsory until the 2022 season. From December 2021, all sugarcane growers in the Wet Tropics, Burdekin, and Mackay-Whitsunday regions are required to have an N&P budget. It is compulsory to have a nitrogen (N) and phosphorus (P) budget for the 2023 season before applying any fertiliser to sugarcane.

Things to know!
  • If you apply mill mud or mill mud/ash mixtures at 100t/ha or higher, you must take this into account when calculating your N and P application amounts for that paddock.

  • District Yield Potential: If you are in the Burdekin where there is more than one DYP (150t/ha and 180t/ha), you need to have historical yields showing three blocks that have yielded above 150t/ha in the last 15 years to use the 180t/ha DYP N rates.

  • Soil samples must be taken prior to applying planting fertiliser and are valid for 12 months after the sampling date. For more information, please see the following:

What is an N&P budget?

An N&P budget is the total calculated kilograms (kg) of nitrogen and phosphorus that you can apply to your sugarcane area (excluding fallow). Soil sample data and the SIX EASY STEPS (6ES) are used to calculate these amounts. However, there is now added flexibility about where you can apply N and P; if you do not exceed your total calculated amount of N and P applied to the farm, the rates applied to each block are not regulated. An N&P budget also includes management zone maps if it is deemed that the farm requires different management zones. N and P can be moved around the farm to suit block requirements. Do you have a lower yield potential in late cut or older ratoons and want to invest more nutrition in your plant cane or early ratoons? Nutrient can be moved from low returning blocks to high performing areas. If you are comfortable with your farm productivity after fertiliser application according to your 6ES recommendation, there is no requirement for you to move N and P around your farm.

How do I prepare an N&P budget?

The first N&P budget (and every 5th year thereafter) needs to be developed by an Appropriate Person. An Appropriate Person is a person with professional qualifications, training, skills, or experience relevent to completing an N&P budget. However, as a grower, you can update your own N&P budget for the following 4 years. A grower may be their own Appropriate Person if they demonstrate that they have the appropriate skills, qualifications and/or experience to develop an N&P budget. You do not need to be an Appropriate Person to update your budget.

How can I use an N&P budget?

An N&P budget allows you to manage according to priorities. You can use your budget to have one fertiliser rate across your top dress for your plant cane or minimise the fertiliser rates across your ratoons. Keeping track of your fertiliser applications through the season will help gauge how much N and P you have remaining in your budget towards the end of the season. It also gives you the opportunity to change rates in response to any variations you made in your initial plan. This ensures you remain within the allowable limits of your N&P budget. For example, if you planned to use a blend with sulphur and accidentally ordered the same blend but without sulphur (and applied it at the same rate) the N% will likely be higher, resulting in a higher than intended N rate being applied. Catching this early means you can potentially reduce the N rate on a late cut ratoon, bringing your total N (kg) used within the allowable limit. The regulatory changes means that if total N applied to the farm is within the calculated amount for the farming area, growers are compliant.

This article was originally published in the Autumn 2023 issue of Farmacist News. Download the printable version using the link below:

N&P Budgets for Sugarcane Autumn 2023
Download PDF • 78KB


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