Project code: NA
Project manager: Adam Hancock
Project duration: July 2023 to June 2024
About the project
This project aims to improve nitrogen fertiliser decision making on farming landscapes, both to maximise agronomic return and minimise environmental impact. Through plant breeding and improved soil management, intensive farming practices have increased and with it an increase of nitrogen fertiliser application. Nitrogen fertiliser requirements on farm have increased faster than local research has kept up with validating and extending improved practices and decision making. This poses challenges in landscapes which host sensitive environmental sites. Further work is needed for farming practices to continue to maintain the health of the environmental sites which they host.
The project will focus on one of the highest nitrogen demanding crops in the Limestone Coast, Durum wheat. Durum wheat has a high protein demand (the nitrogen requirement calculation for 6t/ha durum at 13% protein is (6 x 13 /0.57) x 50% efficiency = 273kg of N or 594kg of urea). This high nitrogen demanding system provides an ideal platform for this project to educate the community on modern nitrogen budgeting practises which includes improved measurements of soil nitrogen cycling, soil organic carbon mineralisation modelling and also improved understanding of organic matter immobilisation. This results in a more accurate nitrogen application both in rate and timing. The project seeks to extend new terminology into nitrogen decisions; in the future, landscape managers will need to consider the amount of free nitrate nitrogen in the soil profile. Improved budgeting using modelled mineralisation reduces the mean residency time of nitrate nitrogen in the farming landscape which is a more measured way of preventing soil organic carbon decline from modern high nitrogen demanding economies.
Because the high nitrogen demand is largely driven from the high protein output, the project will validate research in the field using the chlorophyll sensors relationship to final wheat grain protein. Readings will be collected at a stage during the season while there is still a 21-day window to manipulate nitrogen application to improve grain protein, meaning this relationship could be utilised in season to make nitrogen fertiliser decisions. Improving the communities understanding of synchronising nitrogen application to nitrogen demand in any farming system is a proven method to reduce nitrogen loss pathways to the environment including leaching, run off and gases loss via volatilisation and denitrification, a process with the potential to produce powerful nitrous oxide greenhouse gases.
The location for the high nitrogen demanding system demonstration will focus on flood irrigation in the upper Limestone Coast.
Nitrogen application budgeting commonly utilises soil testing, nitrogen mineralisation modelling and forecast crop demand to make recommendations. The project aims to upskill the community to provide more detail into a nitrogen application budget by adding to the quation carbon nitrogen ratio and cycling of organic matter. This will provide a better understanding of nitrogen use efficiency by forecasting the nitrate nitrogen status of the soil.
The project will also take the opportunity to use and educate land managers on the latest research using enhanced nitrogen fertilisers with inhibitors to prevent denitrification.
Project Objectives
- Establish a replicated randomised trial site in a Durum paddock at Padthaway on flood irrigation with 14 nitrogen treatments.
- To observe a nitrogen response to urea applications and observing the application of new enhanced nitrogen fertiliser products.
- Improve N budgeting calculations through including additional nitrogen and carbon pathways.
- To assess the relationships between tissues testing and chlorophyll sensor readings at critical growth stages against final grain yields and protein.
- Create a model from the chlorophyll sensor and final grain protein at certain growth stages to validate if growers could use this tool to synchronise nitrogen application with crop demand.
- Communicate outcomes of project with local growers and others in the community.
This project is funded by:
This project is supported by the Limestone Coast Landscape Board Grassroots Grants program and is funded by the regional landscape levy.

This project is delivered in partnership with:
Southern Australian Durum Growers Association
Elders
SARDI
Project resources:
2024_The Prosperous Farmer podcast_Season 5, Ep 5_Nitrogen fertiliser decision making on durum wheat with Adam Hancock
2023 MFMG_Trial Results Book_Chapter 3