Farm Tender

Optimising Fertiliser investments

Work is underway to provide grain growers in the southern cropping region (Victoria, South Australia and Tasmania) with the confidence, knowledge and ability to make more effective and profitable nutrient management decisions.

A new Grains Research and Development Corporation (GRDC) investment is focused on increasing growers’ use of soil and plant testing data to better inform their fertiliser decision-making.

The three-year investment, led by Agronomy Solutions in conjunction with Australian Precision Ag Laboratory (APAL), CSIRO, Landmark, Hart Field-Site Group and AgCommunicators, will develop an economic framework to quantify the likely returns from improved nutrient management techniques and the opportunity to boost farm profit while managing risk.

By 2022 – as a result of this “Using soil and plant testing data to better inform nutrient management and optimise fertiliser investments for grain growers in the southern region” investment – the GRDC aims to improve nutrient management best practice through the increased use of soil testing.

Leading the project on behalf of Agronomy Solutions is consultant Harm van Rees (project coordinator), who is being supported by research leader Sean Mason, of Agronomy Solutions.

Dr Mason says the project will begin with an initial economic analysis of soil and plant testing approaches – including aspects such as frequency, phase in the rotation, sampling intensity, soil depths and sampling in controlled traffic paddocks.

“There will also be a series of consultative focus groups this year, which will investigate grower attitudes and motivations, barriers to adoption and key extension and communication messages,” Dr Mason says.

“We are looking for feedback from a whole spectrum of growers – from those who base their fertiliser decisions on regular soil testing, those who have previously used soil tests but don’t anymore, growers who rely on recommendations from their advisers, through to those who have never used soil tests but instead adhere to an entrenched fertiliser regime.

“We are keen to know why these growers do what they do when it comes to making decisions about their fertiliser programs, as their insights will help to inform our approach to influencing practice change.”

Project adviser Sean Mason, of Agronomy Solutions: “We are keen to know why all these growers do what they do when it comes to making decisions about their fertiliser programs, as their insights will help to inform our approach to influencing practice change.”

From here, an intensive, high-impact soil and plant testing demonstration program involving approximately 100 growers across the southern region will then be undertaken throughout 2019 and 2020.

Growers interested in improving fertiliser returns will be invited to participate in the program and those who do will be provided with subsidised soil sampling and analysis, interpretation of results and fertiliser recommendations for about six paddocks per grower each year.

At nutrient responsive sites, participating growers will be encouraged to instigate fertiliser test strips to illustrate responses, supported by plant tests. The impact on nutrient use efficiency and profit for each grower (costs, input savings and/or increased income) will be estimated and soil data will be compiled and trends across the region summarised each year.

Dr Mason says about 5000 soil profile samples will be collected each year which will include measuring at least 40,000 individual analytes annually through the two-year demonstration program. This will provide a useful snapshot of nutrient status and soil fertility in the southern region, and could be used to highlight emerging issues such as soil acidity and declining organic matter.

The project will involve field days and crop walks, and further workshops will be held in 2019 and 2020 to provide growers and advisers with updated knowledge and insights from the work.

“GRDC surveys currently indicate that there is low adoption of soil and plant test data to underpin their fertiliser programs, which is why this project has been initiated by the GRDC,” Dr Mason says.

The economic value of nutrient management practices in terms of increased nutrient use efficiency – including savings where soil nutrient levels are high, or increased crop production, quality and income from increased fertiliser inputs where soil nutrient levels are low – will be widely promoted throughout the duration of the project and beyond its completion.

Picture - Harm van Rees