RiskWi$e Project – Theme 2 Managing Phosphorus in the Farming System (Enterprise Agronomic Decisions)
GRDC National Risk Management Initiative (RiskWi$e): NSW Action Research Group (ARG) – 2023 to 2028
NSW ARG is led by CSU, with the project funded by GRDC.
The national RiskWi$e initiative is a long term GRDC funded project, aimed at improving decision making for grain growers by helping them to better understand and manage risk.
For more information on the national RiskWi$e project please click on the link below:
Theme 2: Phosphorus savings in Farming Systems – what risk?
The Participatory Action Research (PAR) process identified phosphorus (P) management as a priority amongst growers and advisors in the area. With nitrogen work underway, P is the next largest, unavoidable expense for growers. In the target area (wider Griffith region) many of the soils have Colwell P values >40 mg P/kg soil.
As growers have gradually accumulated P in their soils to above the critical range, they wanted to know where budget forecasts show low or negative profit outcomes, can they reduce P inputs without impacting profits in the year of implementation and in subsequent years.
As a result, Ag Grow Agronomy is testing P saving decisions to inform risk/reward and profit by testing P application methodologies to establish:
- if short term input cost savings can be achieved with little or no risk to profit outcomes and
- if more flexible P input arrangements produce similar results to the set input arrangements
A small plot experiment was established in 2024, setting up initial starting Cowell P values (~40 ~60 and ~90), allowing P saving strategies to be tested from 2025. From 2025 yield and cost outcomes from different P replacement strategies for different starting Colwell P values will be tested.
