Research Question

Growers who attended the Tatyoon NGN Forum (2022) identified a need to better understand soil nitrogen (N) reserves and supplies, the efficiency of the uptake of N from fertiliser applications into the crop, and how to best optimise fertiliser decisions to maximise returns in the high rainfall zone (HRZ). Factors affecting fertiliser efficacy in the HRZ extend to waterlogging and loss pathways such as denitrification and leaching, further contributing to uncertainty around fertiliser decision making. Attendees at the NGN Forum, believe they are losing 20-50 % of the urea applied, and are keen to reduce N losses. Southern Farming Systems is running a series of workshops aimed at upskilling advisors and farmers to better understand the key drivers of efficient and profitable use of N fertilisers. The workshops will investigate fundamentals such as measuring soil N, mineralisation, N loss pathways, N products, timing of application and placement. Establishment of a trial site in the area will also provide N response data which can be used in the program. This will then lead into an exercise that would explore how diminishing returns are calculated, and more advanced learning of how systems contribute to the N balance. Focus paddocks will be used so growers can test their new skills learnt in monitoring their N usage and efficiency. The workshop group will also have a catch up the following season to discuss outcomes from 2024.

Research Information & Objectives

Workshops

Workshop 1 - Economics & Diminishing Returns, 19 June 2024, Mininera

Knowing what type of nitrogen to buy and when for your farming system; Understanding of when to start and stop applying nitrogen; Understanding the market and what market changes can mean to your farming business and decisions.

Presentations:

Vitor Pistoia, Analyst, Rabobank

James Hagan, Economist, Queensland Department of Agriculture & Fisheries

Craig Drum, Agronomist, Dagro Agronomy

Workshop 2 - The N Factor : Soil & Nitrogen Interactions 1 April, 2025

Nitrogen Cycle; Understanding soil & nitrogen interactions, Understanding soil types and nitrogen, use, loss and tie-up

With Dr Mark Farrell CSIRO, Jon Midwood Tech Crop and Greta Duff, SFS

Workshop 3 - How technology can help manage Nitrogen

Understanding the precision agriculture tools available to manage Nitrogen through testing to application and the benefits.

Workshop 4 - Decision Making

Understanding the drivers you use when making decisions, using a decision matrix, understanding critical factors that effect your decision, bringing together economics and agronomics in the decision.

Trial Reports

Duff, G (2025) The development of nitrogen yield curves in South-West Victoria, Southern Farming Systems Trial Results 2024, P22-29

• Greta DuffResearch and Extension Coordinator0428 871 900gduff@sfs.org.au