[Music plays] (Simon Speirs) In Australia, approximately half
of our grain growers use soil testing once
every three years to help understand
soil nutrient status and to assist with
fertiliser decision making. This low frequency of
use of soil testing reflects variable levels of confidence
amongst advisors and grain growers. There are continuing doubts over the
reliability of soil testing methods as a means of predicting
plant nutrient requirements. There is also concern
about the accuracy and reproducibility of analyses between different laboratories. While for some there tends
to be limited understanding of the soil processes that contribute
to crop nutrient requirements, and among others a
view that collecting soil samples is time
consuming and unprofitable. The grains and
fertiliser industries have made several moves to
overcome these challenges. [Music plays] (Ken Peverill)
So almost 30 years ago, ASPAC, the Australasian Soil
and Plant Analysis Council, introduced a regular program of
inter-laboratory proficiency testing in order to help improve
analytical reproducibility between different soil
testing laboratories and to restrict the range
of soil tests used. About the same time,
ASPAC also undertook the task of collating all soil
test interpretation guidelines from agricultural trial work and they incorporated this
in the reference book “Soil Analysis: an interpretation
manual” that was published in 1999. In 2008 Fertilizer
Australia introduced the Fertcare
accreditation scheme which applies for individuals
and corporate systems so that they may best set
best management practices in soil sampling, soil analysis,
interpretation of data and formulating fertiliser
recommendations. (Simon Speirs) Between
2008 and 2012, ‘Making Better Fertiliser Decisions
for Cropping Systems in Australia’ was undertaken with funding of
more than three million dollars from the Grains Research
Development Corporation and collaborators in the grains
and fertiliser industries. The principal project aim was to improve
the reliability and consistency of soil test interpretation
for preferred nitrogen, phosphorus, potassium
and sulphur soil tests. The project undertook the challenge
of collating all suitable experiments into a single
repository known as the Better Fertilisers
Decisions National Database. The database includes
1,800 nitrogen, 2,600 phosphorus, 460 potassium, and 290 sulphur experiments. Experiments had been undertaken
predominantly in wheat, but there were also moderate
numbers of experiments for barley, canola and lupins as well as a small number of
experiments for other grain crops. The team developed a web-based tool,
called the BFDC Interrogator, to enable calibration
relationships to be derived from the soil test-crop response
data held in the national database. The BFDC Interrogator
enables registered users to rapidly derive calibration criteria
for soil test interpretation. To assist users the team developed
and rolled out a train-the-trainer package to the grains and
fertiliser industries. This enabled people from the
industry to train others and this approach was possible
through the ongoing collaboration of the fertiliser industry and through key agribusinesses
partners in the project team. (Ken Peverill) This Special Edition
in the Crop and Pasture Science outlines the development
of the BFDC Interrogator and the calibration methods used to
derive critical soil test criteria. It represents a condensation of
outputs from the BFDC Interrogator for various N, P, K and S soil tests
used across a range of cereal, oilseeds and pulse crops. Two papers also address different
soil P tests in order to determine what is measured and how
different soil test methods compare when the same
data set is used. The special edition concludes with
reports on the training approach used to roll out the national
database to advisors and identifies lessons learnt
and makes recommendations for future R&D in crop
nutrition requirements. [Music plays]