NPK
Financial outlay dedicated to fertiliser applications, is the single biggest variable expense in
producing successful crops.
In this emerging era of climate challenges new thinking needs to be applied to old practices
regarding more efficient use of soil nutrients and fertilisers.
Most available sources of crop nutrient management come from older research.
A 14.6 million dollar crop nutrition investment strategy is being applied to update the understanding,
and the approach.
Nitrogen, phosphorus and potassium crop use efficiency, soil storage and yield responses
are all under the microscope of review...
One of our key focuses for phosphorous management is how soil type influences the response to
fertiliser P. So most of our knowledge has been developed on sandy surface soils or loamy
surface soils and over the last 5 to 10 years it's become apparent that our current recommendation
systems don't work that well for gravelly soils in particular the forest gravel soils.
Nutrient availability is under pressure from a variety of factors such as declining rainfall,
soil amelioration and evolving crop sequencing.
So all of our work, all of our field experiments are designed so that we can use them for economic
analysis so our intent is to build large data sets that we can do economic analysis on as
the project progresses and examine where the profitable responses are.
Collaboration between project lead, the University of WA and research industry partners DPIRD,
Murdoch University and CSIRO is instrumental to plugging the knowledge gap.
Soil sampling and nutrient analysis are also key to the project.
With all of our field experiments we are heavily focussed on characterising the nutrient supply
at those sites so we have a heavy focus on soil sampling at our long term sites, we're
measuring the surface and profiles annually to track changes over time, and we're also
measuring shoot nutrient concentration at each site over each year as well, which allows
us to monitor plant nutrient status over time and relate plant nutrient status to soil nutrient
supply.
University researchers are contributing expertise to help increase grower confidence in fertiliser
application.
As part of this project we have a postdoctoral researcher fellow at University of Western
Australia and and at the moment he's working on characterising soil phosphorus forms in our soils and how
that relates to soil supply to our crops.
So the Laboratory work that we have at the moment is focussing on residue decomposition.
So the residue type and environmental factors that affect residue decomposition.
It's still early in the project but updated guidelines and decision support models are
expected to be delivered towards the end of 2021 and 2022.
Meanwhile growers are encouraged to apply new thinking - with renewed confidence: nutrient
supply and greater fertiliser efficiency, nutrient distribution after soil renovation,
and new in-field soil sampling methods ultimately aimed at boosting crop profitability.
At the end of the day this project is really about achieving greater profit so if we have
better understanding of soil nutrient supply, we can match our fertiliser inputs better
and achieve greater profit from them.